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IB Geography- Ultimate Study Guide
Patterns and Change
This is the core theme for DP Geography and it helps to provide a foundation for exploring key global issues. It encompasses four key units:
Populations in transition
Disparities in wealth and development
Patterns in environmental quality and sustainability
Patterns in resource consumption
Populations in Transition
Population Trends:
Global population change 1930-2020
In most regions, population growth has increased between 1930 and 1960, and then again between 1960 and 1990 (Africa, South America, Australia, Asia) except North America and Europe.
In contrast, the projected changes for 1990-2020 show that the population growth rate will fall all over the globe
Exponential growth
Increasing/accelerating growth rate
The world’s population is growing rapidly, most of it being recent
Global pop. Doubled between 1650 and 1850, 1850 and 1920, and 1920 and 1970 (taking less and less time to double)
Up to 95% of pop. growth is taking place in LDC
This trend of growth is defined as exponential growth
Despite this, world population is expected to stabilize at about 12 billion by around 2050-80
This growth creates:
Pressures on the government to provide for their people
Environmental pressure
Increased risk of disease and malnutrition
Greater differences between poor and rich countries
Demographic change and global trends
The annual growth rate is found by subtracting the crude death rate (% of deaths per thousand people, also referred to by number of deaths per thousand) from the crude birth rate (% of births per thousand people, also referred to by the number of births per thousand) and is then expressed as a percentage
The highest growth rates are found in Africa, and lowest in North America and Europe
Birth Rates:
Measurements of fertility
Crude birth rate (CBR) = total number of births/total population x 1000 per year (doesn’t consider age and sex structure of population), total number of births per thousand.
Standardized birth rate (SBR) in contrast to the CBR, gives a birth rate for a region based on the premise that the region’s age composition is the same as that of the whole country.
Total fertility rate (TFR) is the average number of births per woman.
The general fertility rate is the number of live births per 1000 women of reproductive age in a country
GFR = number of live births/number of women in reproductive age x 1000 per year
The age-specific birth rate (ASBR) = number of births/women of any specified age x 1000 per year
In general, the highest fertility rates are shown in LEDCs (Less economically developed countries) and the lowest in MEDCs (More economically developed countries), with the TFR in MEDCs being an average of 1.7, and in LEDCs an average of 5.8.
Changes in fertility
Changes are a result of a combination of sociocultural and economic factors
Sociocultural factors and fertility
Status of women
The status of women is assessed by the gender-related development index (GDI), which measures the inequality between the sexes in life expectancy, education and the standard of living.
In countries where the status of women is low and few women are educated or involved in paid employment, birth rates are generally higher
An example is Singapore, where the status of women has improved, and from 1960 to 2000, because of this improvement, the rate fell from 3.0 to 1.5
Level of education and material ambition
In general, the higher the level of parental education, the fewer the children
Middle-income families with high aspirations but limited means tend to have smaller families
To improve standards of living, they limit family size
An example is Ethiopia (2005) where uneducated women had TFR’s of 6.1 and educated ones with a TFR of (2.0)
Type of residence
People in rural areas have more children than in urban
This is because:
More rigid social pressures on women
Greater freedom and less state control in rural areas (e.g. China’s one-child policy is enforced less rigorously in rural areas)
Females in rural areas have fewer educational and economic opportunities
In some urban areas, such as shanty towns, there are high levels of fertility because of their youthful population structure
Religion
In general, most religions are pro-natalist and favor larger families (are against abortions, sterilization, etc.)
The health of the mother
Sometimes, women who are unhealthy and have some miscarriages become pregnant more often to compensate
Economic factors and fertility
Economic Prosperity
Not complete correlation, but there are some links
Economic prosperity favours an increase in the birth rate while increasing costs lead to a decline in the birth rate
The UN believe that a reduction in the high birth rates in the LEDCs can be achieved only by improving the standards of living in those countries
In addition, equitable distribution of wealth tends to lower the fertility rate
Canada has a higher level of GNP per capita (US$) than Tanzania (20,000 to 200) and therefore has a lower TFR (1.6 in comparison to 5.5)
The need for children
High infant mortality rates increase the pressure on women to have more children (replacement/compensatory births)
Larger families in agricultural societies help provide labour for the farm
Mortality:
Measurements of mortality
The crude death rate (CDR) = total no. of deaths/total population x 1000 per year(number of deaths per 1000 per year)
Poor measurement of mortality (doesn’t consider many other factors, Pakistan’s crude rate of 7.8% is less than that of Denmark’s 11%
Better measures are the standardized mortality rate (SMR), and age-specific mortality rates (ASMRs) such as the infant mortality rate (IMR)
IMR = total no. of deaths of children <1 year old/total no. of live births per year x 1000
The child mortality rate (CMR) = total no. of deaths of children aged 1-5 years/total number of children aged 1-5 years x 1000
Life expectancy (E0) is the average number of years that a person can be expected to live, given the demographic factors are constant
Patterns of mortality
Patterns of mortality differ from MEDCs to LEDCs
In MEDCs, the death rate falls steadily to 9% with high life expectancies (75+)
In LEDCs, the opposite can be seen, but due to steady improvements over the past few decades in the food supply, water, sanitation and housing, the situation is improving
However, this trend has unfortunately been reversing as a consequence of AIDS
Population Pyramids:
Population pyramids tell us a great deal of information about the age and sex structure of a population:
A wide base suggests a high birth rate
A narrowing basis suggests a falling birth rates
Straight or near-vertical sides show a low death rate
A concave lope suggests a high death rate
Bulges in the slope indicate high rates of immigrant
Deficits in the slope show out-migration or age-specific or sex-specific deaths
Population pyramids can also be used to show the racial composition of a population or the employed population group
Pop. Pyramids are important because they tell us about population growth.
They help planners to find out how many services and facilities, such as schools and hospitals will be needed in the future
Demographic transition model:
4 stages
Stage 1: Pre-transition
High BR
High infant mortality rates
High DR
High fertility
Many young, few old
Upwards curving population pyramid
Stage 2: Early-transition
DR declines rapidly (better medical care)
BR + FR remain high
Many you people
Infant mortality declines
Triangle shape population pyramid
Stage 3: Late-transition
BR declines rapidly
DR declines slowly
FR declines
Increasing older people
Rounded triangular shape
Stage 4: Post-transition
Low BR + DR
Fertility rate around 2.1 (replacement rate)
Greying society
Stable/slow pop growth
Bullet-shaped population pyramid
Gender and Change:
Gender and population growth
High rates of population growth are associated with a low status of women in society
The UN Decade for Women, from 1975 to 1985 recommended three important points for action:
There should be legal equality for women
Further development needs to improve on the substandard role that women play
Women should receive an equal share of power
Gender and social role
In 1970, Esther Boserup identified women as having been left behind in the development process
The social roles that women have are mostly
Biological reproduction
Social reproduction
Economic reproduction
These three roles create a great deal of physical and psychological stress
It is believed in sub-Saharan Africa that:
Up to one-third of women are pregnant or breastfeeding at any one time
Women comprise over half the workforce, sometimes 70%
Women grow over 80% of the food eaten and contribute half of the region’s cash crops
Women and development
Strategic or political change is needed to attain equality and empowerment
Progress for sexual equality has been painfully slow
For example, the illiteracy rate is much higher for girls than boys, and generally, women are becoming poorer (supposedly)
Gender inequalities in adult literacy are higher in African and Arab cities
The reasons for slow progress
Conditions are deteriorating in a large part of Africa
As a result of structural adjustment programmes (SAPs), countries spend less money on health and social welfare (disproportionately borne by women)
There is a lack of commitment to women by man countries and by donors
Women have to work as well as be the head of the household, but they have little legal status
Responses to high and low fertility:
Political factors and family planning
Most governments in LEDCs have introduced programmes aimed at reducing birth rates
Effectiveness depends on:
Focusing on family planning and not just birth control
Investing sufficient finance in the schemes
Working in consultation with the local population
Where birth controls have been imposed by the government, less successful (except China)
In MEDCs, financial and social support for children is often available to encourage a pro-natalist approach
However, where fears of negative pop. Growth (Singapore), more direct measures taken to increase birth rates
Dependency ratios
The dependency ratio measures the working population and the dependent population
Population aged <15 + population aged >60 (dependents)/Population aged 16-59 (economically active)
In the developed world, there is a high proportion of the elderly
In the developing world, there is a higher proportion of youth
Aging ratios
The future trend in the old-age dependency ratio for the EU countries is increasing
Currently for working individuals for each person 65 or older
Will drop down to two, or worse, generally due to the low birth rates
Migration:
Types of movement
Migration is the movement of people, involving a permanent (more than one year)change of residence
Internal or external (international), voluntary or forced
Patterns of migration according to Ravenstein
Most migrants proceed over a short distance
Due to limited technology and transport, (poor communications), people know more about local opportunities
Migration occurs in steps
Typically from rural to small town, to large town to city (people become “locked in” to the urban hierarchy)
As well as movement to large cities, movement away (dispersal)
The rich move away and commute from nearby villages and small towns
Urban dwellers migrate less than rural dwellers
Fewer opportunities in rural areas
Women are more migratory than men over short distances
Especially for marriage and in societies where the status of women is low
Migration increases with advances in technology
Transport, communications, spread of info
Migration according to Lee (1966)
Described migration in terms of push and pull factors
Push factors are negative features causing a person to move away from a place(unemployment, natural hazards etc.)
Pull factors are the attractions (better wages, schools etc.)
Limitations of models
Models have many assumptions
Are all people free to migrate?
Do all people have skills, education etc. allowing them to move
Are there barriers to migration
Is distance a barrier to migration
Migration:
Origin of disparities:
Inequalities in development
Despite considerable economic growth in many regions, the world is more unequal than it was 10 years ago
Some countries left behind in the “poverty cycle”, aren’t able to develop as fast as others
Even within the group of countries that are commonly thought of as poor, there is variation in levels of poorness
For example, both Taiwan and South Korea have extremely high levels of GNI per capita
Employment
The gulf between formal and informal economies
Widening gap between skilled and unskilled labour
Growing disparities in health, education and opportunities for social, economic and political participation
Inequalities between and within countries have accompanied globalization
These have had many negative consequences in many areas, including employment, job security and wages
Unemployment remains high, especially youth unemployment
Youths are two to three times more likely than adults to be unemployed and currently make up as much as 47% of the total 186 million people out of work worldwide (most labor markets unable to absorb them)
Millions are working but remain poor (don’t reach the poverty threshold of 1$ a day)
A large majority of the working poor are informal agricultural workers (globalization led to an explosion of the informal economy)
In many countries, wage inequalities (esp. between skilled and unskilled workers)
Falling real minimum wages and sharp rises in the highest incomes
Rich countries with income gap, such as Canada, UK and USA
Parental education and inequality
Link between investment in education and poverty is extremely fundamental
Education may raise incomes of those with it (and those with higher qualifications tend to have less children)
Global disparities and change:
Changing global inequalities
PPP: what a person can by with their income at local prices
Until 200 years ago, Asia was the dominant world economic power
Today rapid econ. growth rates are helping the region regain its former position
Used to be Asia dominant, with Europe and Africa in 2nd and 3rd around the year 100
Currently, Asia is almost dominant, with Australia, Canada, New Zealand and the US combined in second, then after that Europe, Latin America, Japan, Africa and USSR
Income Inequalities (“Twin Peaks” of rich and poor)
The greatest contributors to income inequality are the largest countries at either end of the spectrum, the “Twin Peaks”
One pole represents the 2.4 billion people whose mean income is less than $1000 a year and includes people living in India, Indonesia and rural China. With 42% of the world’s population, this group receives just 9% of the world’s PPP incomes
The other pole reps 500 million people whose annual income exceeds $11500
Group includes USA, Japan, Germany, France and the UK
Combined, account for 13% of the world’s population but use 45% of the world PPP income
In the last 25 years, the main changes in come between diff. regions of the world include:
The continued rapid econ. growth in the already rich country relative to most of the rest of the world
The decline in real income of sub-Saharan Africa and eastern Europe
Relatively modest gains in Latin American and Arab states
Some most important global disparities relate to lack of decent work and low incomes
According to ILO (international labour organization), about 200 million people don’t have any form of work
Social inequalities
Despite some progress, health and education inequalities have widened, especially within countries
Sub-Saharan Africa and parts of Asia are in the worst predicament
Wide gaps in access to immunization, maternal and childcare, nutrition and education
Gender gaps in access to education have narrowed somewhat, but persist
Indigenous people, persons with disabilities, older people and youth are typically excluded from decision-making processes that affect their welfare
Environmental impacts
Today’s disparities are also closely linked to human impact on environment
Poor frequently end up with poor land, water, fuel and other natural resources (limit productivity)
Patterns in environmental quality and sustainability
Atmosphere and Change:
Global warming
Refers to the increase in temperatures around the world that has been noticed over the last 50 years or so, and in particular since the 1980`s
Greenhouse effect is the process by which certain gases (water vapour, CO2, methane etc.) allow short-wave radiation from the sun to pass through to heat up the earth, but trap an increasing proportion of long-wave radiation from the earth
Enhanced greenhouse effect is increased amount of greenhouse gases in the atmosphere due to human activities
CO2 levels have risen from about 315 ppm in 1950 to 355 ppm and are expected to reach 600 ppm by 2050
Caused by burning of fossil fuels, deforestation (also removes trees that convert the CO2 to oxygen)
Methane is the second largest contributor to global warming (increasing rate of 1% per annum)
Cattle convert 10% food they eat into methane, emit 100 million tonnes of methane each year
Natural wetlands and paddy fields also emit 150 million tonnes annually
CFCs are synthetic chemicals that destroy ozone and absorb long wave radiation from the earth
Increasing at rate of 6% per annum, and are up to 10000 times more efficient at trapping heat than CO2
Effects of global warming
A rise in sea levels caused flooding in low-lying areas such as the Netherlands, Egypt and Bangladesh (over 200 million could be displaced)
Increase in storm activity
Changes in agricultural patterns (decline in the US grain belt, increase in Canada`s growing season)
Reduced rainfall over the USA, southern Europe
Extinction of up to 50% of species of wildlife
Implications of climate change
Global warming
Climate change
Extreme events
Long term change
Temperature, wind, pressure, precipitation, humidity
Storms, drought, fire, erosion, landslides, sedimentation, avalanches, pests and diseases
Sea level rise
Coastal erosion, flooding, salination
River flooding, bank erosion,
Waves, Tsunami
Policies to combat climate change
Emission of main anthropogenic (man-made) GHG, CO2, influenced by size of the human population, amount of energy used per person, level of emissions resulting from that use of energy
A variety of options which could reduce emissions, especially from the use of energy, are available
Reducing CO2 emissions can be done through:
Improved energy efficiency
Fuel switching
Use of renewable energy sources
Nuclear power
Capture and storage of CO2
Another measure involves increasing the rate at which natural sinks take up CO2 (i.e. increase the number of forests)
Water usage and change:
Changing supply and demand
Use of water has increased six time in past century, world population tripled
Some rivers that formerly reached the sea no longer do so, diverted for our use (example of Colorado in the USA)
Half world’s wetland disappeared, today 20% of freshwater species are endangered or extinct
Many aquifers are being depleted, and water tables in many parts of the world are dropping at an alarming rate
World water use is projected to increase by about 50% in next 30 years
Estimated by 2025, 4 billion people will live under conditions of sever water stress (conditions particularly severe in Africa, Middle East and south Asia)
May fuel armed conflicts
Currently estimated 1.1 billion people lack access to safe water, 2.6 billion without adequate sanitation, and more than 4 billion do not have their waste water treated to any degree
Water supply
Depends on several factors in the water cycle, including rates of rainfall, evaporation, use of water by plants (transpiration), river and groundwater flows
Less than 1% of freshwater available is available for people to use (everything else locking in ice sheets and glaciers)
Globally, 12500 km3 of water are considered available for human use on an annual basis
About 6600 m3 per person per year
Only 4800 m3 likely per person in 2025
Freshwater is not evenly distributed around the world
Three-quarters of rainfall occurs in areas containing less than one-third of the world's population (whereas two-thirds of the world's population live in areas receiving only one-quarter of the world`s annual rainfall)
20% of global average runoff each year is accounted for by the Amazon Basin, a vast region with fewer than 10 million people
India gets 90% of its rainfall during the summer monsoon season (other times rainfall is extremely low)
Water stress
When per capita water supply is less than 1700 m3 per year, an area suffers from ``water stress”, and is subject to frequent water shortages
In many areas, less than 1000 m3 per capita, causing problems for food production and economic development
2.3 billion people live in water-stressed areas
Water stress will affect 3.5 billion people (48% of world pop.) projected by 2025
Water use
Currently, quantity of water used for all purposes exceeds 3700 km3 per year
Agriculture is largest consumer (two-thirds of all water from rivers, lakes and groundwater
1960, water used for crop irrigation risen by 60-70%
Industry uses about 20% of available water, and municipal uses about 10%
Pop. growth, urbanization and industrialization have increased the use of water in these sectors
As world pop. and industrial output have increased, by 2025 global availability of freshwater expected to drop 25% from year 2000 figure to 5100m3
Water scarcity
Two types of water scarcity affect LEDCs in particular:
Physical water scarcity
Occurs where water consumption exceed 60% of the usable supply
To help meet water needs, countries such as Saudi Arabia and Kuwait import much of their food and invest in desalinization plants
Economic water scarcity
Country physically has sufficient water, but additional storage and transport facilities needed (embarking on expensive water development projects, of too high a cost)
In addition, in LEDCs access to adequate water supplies is most affected by exhaustion of traditional sources such as wells and seasonal rivers
In many poor countries farmers use, on average, twice as much water per hectare as industrialized countries, but their yields are three times as low (six times difference in efficiency of irrigation)
Water quality
Needs to be of adequate quality for consumption
WHO estimates 4 million deaths each year attributed to water-related diseases (cholera, hepatitis, malaria and other parasitic diseases)
Real problem of drinking water and sanitation in developing countries is too many people lack access to safe and affordable water supplies and sanitation
Global water supply and sanitation
Urban areas are better served than rural ones, and countries in Asia, Latin America and the Caribbean are better off than African countries
Many piped water systems however do not meet water quality criteria, leading more people to rely on bottled water (as in major cities in Columbia, India, Mexico, Thailand, Venezuela and Yemen)
Some cases, poor pay more than rich for water
Port-au-Prince, Haiti, survey have shown households connected to water system typically paid around $1.00 per cubic metre, while unconnected customers forced to purchase water from mobile vendors paid from $5.50 to $16.50 per cubic metre
Sanitation and population growth
Fewer people have adequate sanitation than safe water, and global provision of sanitation is not keeping up with pop. growth
Between 1990 and 2000 number of people without adequate sanitation rose from 2.6 billion to 3.3 billion
Least access to sanitation occurs in Asia (48%), especially in rural areas
Still pressure points, especially in areas of rapid pop. growth
Squatter settlements in many of world’s poorest cities, local authorities unable to or legally prevented from providing sanitation, situation is likely to deteriorate rapidly
Patterns in resource consumption
Ecological Footprints:
Calculating ecological footprint
Everything used for our daily needs comes from natural resources
Ecological footprint measured in acres or hectares, calculates amount of earth`s bio productive space needed to keep a population at its current level of resource consumption
Calculation takes into account:
Arable land:
Amount of land required for growing crops
Pasture land:
Resources required for growing animals for all forms of consumption
Forests:
For fuel, furniture etc., also providing many ecosystem services such as climate stability, erosion prevention
Oceans:
For marine products
Infrastructure needs:
Based on built-up land used for these needs
Energy costs:
Land required for absorbing carbon dioxide emissions and other energy wastes
Ecological footprint, global and national
Planet`s biological productive capacity (biocapacity)is estimated at 1.9 ha per person
Currently, countries are using up to 2.2 ha per person, beyond the planet`s biocapacity to sustain us by 15%
The deficit is showing up as failing natural ecosystems – forests, oceans, soil, water etc.
Planet`s biocapacity is affected by global population as well as rate of consumption
Increased consumption depletes the planet’s carrying, renewal and regeneration capacities
The ecological footprint estimated available to each person would be reduced to 1.5 by 2050
If we continue at the consumption rates of the rich Western countries, we will need 4 to 5 earths to sustain ourselves
The USA is a country with the largest per capita footprint in the world – 9.57
If everyone lived like Americans, Earth could only support 1.2 billion people, but if everyone was like those in Bangladesh, it could support 22 billion people (footprint of 0.5 ha)
Global ecological footprint grew from about 70% of capacity in 1961 to 120% in 1999
The future projections show growth of about 180 to 220% by 2050
Environmental Sustainability:
Environment sustainability index
ESI was produced by a team of environmental experts at Yale and Columbia
Using 21 indicators and 76 measurements including natural resource endowments, past and present pollution levels, and policy efforts, the report creates a “sustainability score” for each country, with higher scores indicating better environmental sustainability
10 most sustainable countries as ranked by the ESI are dominated by wealthy, sparsely populated nations with an abundance of natural resources
Finland ranks first, with Norway, Sweden and Iceland all in the top 5
The only developing nations in the top 10 are Uruguay and Guyana, which have relatively low pop. densities and an abundance of natural resources
Conversely, the only densely populated countries that have received above-average rankings are Japan, Germany, the Netherlands and Italy, some of the richest countries on the list
Environmental sustainability is essential in aiding the poor
Highly dependent on the environment and its resources which provide roughly two-thirds of household income for the rural poor
Climate change is dramatically reshaping the environment on which poor people depend
Climate change increases rainfall variability (droughts and floods), food security, spread of disease, increased risk of accidents and damage to infrastructure
Poor are most vulnerable to these changes and have limited capability to respond to them
Overfishing has led to the collapse of many fisheries, and one-quarter of global marine fish stocks are currently overexploited or significantly depleted
About 60% of the ecosystem services resources evaluated by the UN’s Millennium Ecosystem Assessment (a measure of how ecosystems benefit people), are being degraded or are being used unsustainably
Between 10% and 30% of mammal, bird and amphibian species face extinction
Global timber production has increased by 60% in the past four decades, meaning roughly 40% of forest area has been lost, and deforestation continues at a rate of 13 million ha per annum
Challenges and solutions
Environmental concerns are fundamental to long-term sustainable development
Efforts must be made to improve understanding of the environmental impact of development strategies and to recognize the link between environmental degradation and poverty
The poor, who are most dependent on natural resources and are most affected by environmental degradation, lack the information or access to participate in decision-making and policy development
In contrast, those who influence policy development have little understanding of the costs and benefits associated with environmental policy
Economic growth and the environment are often still viewed as competing objectives
But investing in environmental management can be cost-effective, and it contributes to improving livelihoods
Managing the Korup National Park
Created in 1986 by the government of Cameroon with the support of the WWF
Under the law, human activity in the park is limited to tourism, research and recreation
The project aims to integrate the National Park into the local economy and regional development plans
An example of sustainable development in Korup is that of community forests
These are large areas of forest in which villagers obtain and manage a part of the communal forest sustainably (reviewed regularly by the government and WWF)
Management of Korup is important, contains over 400 species of trees, 425 species of birds, 120 species of fish and 100 mammal species
Over 60 species occur only in Korup, and 170 are considered to be endangered or vulnerable
The changing importance of alternative energy sources:
Renewable resources
Include hydroelectric power, solar, wind and tidal
World potential renewable energy
Wind Energy is the smallest, mostly in North America, Northern Europe, Japan Australia and New Zealand, South America, China, India
Biomass biggest, mostly in South America, North America, the Former Soviet Union and Eastern Europe, Southern Africa, Northern Europe
Hydroelectricity second largest, mostly in North America, South America, Northern Europe, the Former Soviet Union and Eastern Europe
Solar energy is lowest with similar countries possessing the potential to use it
Trends in renewable energy sources
Renewable energy is growing fast
Rates of development of renewable energy sources are far exceeding those of fossil fuels such as oil, coal and natural gas
2006, wind and solar development grew by 20% and 40% respectively
The market for renewable energy sources was about $55 billion worldwide in 2006, with forecasted growth to $226 billion by 2016
Conservation, waste reduction, recycling and substitution:
Recycling
refers to the processing of industrial and household wastes (such as paper, glass and some metals and plastics) so that materials can be reused
Saves scare raw materials and helps reduce pollution
UK fallen behind other EU countries with recycling because there are more landfill sites which are cheaper to use (has recycling target of 33% by 2015)
Reuse
Refers to multiple use of a product by returning it to the manufacturer or processor each time (more energy and resource efficient than recycling)
Reduction
Using less energy, such as turning lights off when you don’t need them
Substitution
Using one resource rather than another (renewable verse non-renewable)
Landfill
Burying of waste in the ground, and then covering over the filled pit with soil and other material
Cheap but not always healthy (mostly domestic waste, some hazardous waste allowed as well)
Fly-tipping
When people/companies dump waste/old equipment
Increasing problem
Done because of increased costs of landfills
Also more goods, such as TVs, computers and refrigerators classified as hazardous and subject to restrictions on how they are disposed of
Introduction of strict new EU regulations means high proportion of new products must be recycled (costly to manufacturers and purchasers)
The Freshwater System
The Hydrological Cycle
Key Terms
Precipitation: the transfer of moisture (rain, snow etc) to the earth's surface from the atmosphere.
Interception: the capture of raindrops by plant cover, which prevents direct contact with the soil.
Runoff: precipitation that does not soak into the ground but flows over it into surface waters.
Groundwater: water held underground in soil or porous rock, often feeding springs and wells.
Evapotranspiration (EVT): the loss of water from vegetation and water surfaces to the atmosphere.
Potential evapotranspiration (pEVT): the rate of water loss from an area if there were no shortages of water
Maximum sustainable yields (MSY): the maximum level of extraction of water that can be maintained indefinitely for a region.
The hydrological cycle, also known as the water cycle, is the continuous movement of water on, above, and below the surface of the Earth.
It's a complex system with various interconnected processes responsible for distributing freshwater globally.
The water cycle involves the exchange of energy, which leads to temperature changes.
For instance, when water evaporates, it takes up energy from its surroundings and cools the environment.
When it condenses, it releases energy and warms the environment.
These heat exchanges influence climate.
The evaporative phase of the cycle purifies water which then replenishes the land with freshwater.
The flow of liquid water and ice transports minerals across the globe.
It is also involved in reshaping the geological features of the Earth, through processes including erosion and sedimentation.
The hydrological cycle is a closed system because water can not be added or lost.
Although water can not be added or lost it can be found in different states and in different locations.
Despite the planet being covered in water, the vast majority is sea water (97.5%). Of the remaining 2.5% the majority is held in glaciers and ice sheets.
Only a very small amount of the world’s water is easily accessible in rivers and lakes (0.00069%)
Closed System:
In a closed system, there is no exchange of matter with the surroundings, only energy.
Hydrological Cycle as a Closed System:
When considering only the movement of water molecules within the Earth's system, it can be simplified as a closed system.
The total amount of water on Earth remains constant, although it continuously changes states and locations through the various processes of the cycle.
Open System:
In an open system, both matter and energy can be exchanged with the surroundings.
Hydrological Cycle as an Open System:
When considering the energy transfers involved in the water cycle, it's clearly an open system.
Solar energy from the sun drives the entire cycle, causing water to evaporate and eventually return as precipitation.
Additionally, a small amount of water vapor escapes Earth's atmosphere, entering the open space, making it a truly open system in that sense.
Precipitation:
This is the initial stage where water vapor in the atmosphere condenses and falls back to Earth as rain, snow, sleet, or hail.
Factors like temperature, pressure, and wind currents influence precipitation patterns, leading to uneven distribution across the globe.
Types of precipitation:
Convectional precipitation: Occurs due to rising warm air, common in tropical regions.
Orographic precipitation: Forced uplift of air over mountains, leading to rain on windward slopes.
Frontal precipitation: Warm and cold air fronts colliding, resulting in widespread precipitation.
Interception:
Before reaching the ground, precipitation encounters various surfaces like leaves, branches, and vegetation.
Some water gets trapped or evaporates directly back into the atmosphere.
Factors affecting interception:
Type and density of vegetation
Leaf surface area
Rainfall intensity and duration
Infiltration:
Water that doesn't evaporate penetrates the ground surface, entering the soil zone. Soil texture, porosity, and moisture content determine the infiltration rate.
Infiltration pathways:
Macropores: Large channels allowing rapid infiltration (e.g., cracks, wormholes)
Micropores: Smaller spaces facilitating slower infiltration
Infiltration impacts:
Replenishes soil moisture crucial for plant growth
Contributes to groundwater recharge
Runoff:
Water that doesn't infiltrate either evaporates or flows over the land surface as runoff.
Types of runoff:
Overland flow: Water sheet flow directly over the land
Channel flow: Water concentrated in streams and rivers
Subsurface flow: Water infiltrating shallow soil layers and moving laterally towards waterways
Runoff factors:
Rainfall intensity and duration
Slope and topography
Soil permeability and saturation
Land cover (e.g., vegetation, urbanization)
Evapotranspiration:
This combined process involves the evaporation of water directly from soil and water bodies and the transpiration of water vapor from plants through their leaves.
Types of evapotranspiration:
Evaporation: Direct change of liquid water to vapor from surfaces
Transpiration: Release of water vapor from plant stomata during photosynthesis
Evapotranspiration impacts:
Returns water vapor to the atmosphere for further precipitation
Regulates surface temperature and humidity
Influences plant growth and ecosystem health
Groundwater Recharge:
A portion of infiltrated water percolates deeper into the soil, eventually reaching the saturated zone below, replenishing groundwater aquifers.
Factors affecting recharge:
Soil permeability and depth
Groundwater table depth
Rainfall patterns and intensity
The Water Balance
The water balance basically looks at the balance between inputs and outputs.
You can look at the water balance at a global level (hydrological cycle), at a local level (drainage basin cycle) or even just a field.
At a global level oceans tend to experience greater outputs (evaporation) than inputs (precipitation).
This is because oceans are large areas with no shade that have regular winds blowing saturated air on land, allowing greater evaporation.
In addition oceans don’t tend to suffer from the same amount of relief and convectional rainfall as land does.
On land, inputs (precipitation) tends to be greater than outputs (evaporation).
This is because lands suffers from larger amounts of frontal, relief and convectional rainfall, as well as much of the lands water being protected underground or in shaded areas reducing evaporation.
At a global level there obviously has to be an equilibrium between inputs and outputs.
The excess precipitation on land is returned to the oceans by channel flow, surface run-off and to a lesser extent groundwater flow.
The excess of evaporation is returned to the land from the sea by winds blowing saturated air on land.
Drainage Basins and Flooding
Key Terms
Drainage basin: the area drained by a river and its tributaries
Water balance: the relationship between the inputs and outputs of a drainage basin
Soil moisture excess: when soil moisture and groundwater is replenished. The excess may lead to saturation and increased surface run-off
Drainage divide or watershed: the line defining the boundary of a river or stream drainage basin separating it from adjacent basins
Discharge: the volume of water passing a given point over a set time
Peak rainfall: The highest rainfall (usually measured in mm) during a storm.
Drainage Basin
Inputs:
The main input to the system is precipitation.
The type of precipitation (rain or snow, etc), the intensity, the duration and frequency all have an effect on the amount of water in the system.
Each subsystem of the drainage basin system will also have inputs and ouputs, and the output from one stage of the diagram will form the input for another.
Precipitation: Any moisture that falls from the atmosphere.
The main types of precipitation are rain, snow, sleet, hail, fog and dew.
Inter-basin transfer: Water that either naturally (due to the alignment of the rock) or with human involvement (pumps and pipes) moves from one drainage basin to another.
Transfer:
The sum of all the water flowing over the drainage basin’s surface is called runoff.
It is made up of streamflow, which is flow through permanent river channels and overland flow or surface runoff.
Overland flow transfers water through the basin either as sheetwash, across the surface, or in tiny channels called rills.
Beneath the surface, water is transferred via throughflow, which is the movement of water through the lower soil towards rivers, and groundwater flow.
Groundwater flow is typically very slow.
Water that has been intercepted by foliage may also be transferred, either directly as throughfall, or by running down branches and stems via stemflow.
Stem flow: When intercepted water runs down the trunks and stems of vegetation.
Canopy drip: When intercepted water drips off the leaves of vegetation (drip tip leaves in rainforests are actually designed to allow this to happen).
Throughfall: Precipitation that falls directly through vegetation.
Infiltration: Water that moves from the surface of the earth into the soil below.
Throughflow: Water that travels through unsaturated ground.
Pipeflow: Water that travels through holes left by root systems and animals burrows.
Percolation: Water that travels from unsaturated into saturated ground.
Groundwater flow (baseflow): Water that travels through saturated ground.
Capillary action (or rise): Water that may move upwards towards the surface.
Channel flow: Water that travels in a river.
Surface run-off (overland flow): When water travels across the surface of the earth e.g. down a hill.
Storage
Water is stored in a drainage basin on the surface in lakes and channels or underground in the groundwater store.
Water reaches the groundwater store via the processes of infiltration and percolation.
During these processes, some water will be stored in the soil and rock.
The amount of water stored will vary depending on the porosity of the soil and on the permeability of the rock.
Water can also be temporarily stored via interception.
This refers to the storage of water on leaf and plant stems.
Dense foliage may result in little water reaching the ground, since it often evaporates from the leaves.
Interception: When water is caught and held by vegetation or man-made structures like buildings.
Surface store: When water is held in the surface of the earth.
This may be a puddle, a lake or a garden pond.
Soil moisture store: When water is held in unsaturated soil.
Groundwater store: When water is held in saturated ground.
Outputs
The final release of the water in a drainage basin is known as its output.
Typically, rivers flowing into the sea will be the main output of a drainage basin. Some water will also be lost via evapotranspiration.
This process refers to direct evaporation, and also to the extend that moisture lost from leaves will result in plants withdrawing water from the soil via their roots.
Evaporation: The process of water turning from a liquid into a vapour. Evaporation only takes place from a body of water e.g. a lake, puddle or the sea.
Transpiration: The evaporation of water from vegetation.
Evapotranspiration: The combined action of evaporation and transpiration
Inter-basin transfer: Water that either naturally (due to the alignment of the rock) or with human involvement (pumps and pipes) moves from one drainage basin to another.
River discharge via channel flow: Water entering the sea and leaving a drainage basin.
A very small amount of water also enters the sea via throughflow and groundwater flow (baseflow).
River Profile
Split into upper course, middle course, and lower course
As river flows, it is shaped by erosion, transportation, and deposition
Erosion
River erosion is the wearing away of the land as the water flows past the bed and banks.
There are four main types of river erosion:
Attrition: occurs as rocks bang against each other gradually breaking each other down (rocks become smaller and less angular as attrition occurs)
Abrasion: this is the scraping away of the bed and banks by material transported by the river
Solution: chemicals in the river dissolve minerals in the rocks in the bed and bank, carrying them away in solution.
Hydraulic Action: this is where the water in the river compresses air in cracks in the bed and banks.
This results in increased pressure caused by the compression of air, mini 'explosions' are caused as the pressure is then released gradually forcing apart parts of the bed and banks.
Transport
Material may be transported by a river in four main ways: solution; suspension; saltation and traction.
The type of transport taking place depends on the size of the sediment and the amount of energy that is available to undertake the transport.
The chemical composition of the parent rock from which sediments originate.
In the upper course of the river there is more traction and saltation going on due to the large size of the bed-load, as a river enters its middle and lower course there is a lot of finer material eroded from further upstream which will be carried in suspension.
Deposition
Where material carried by the river is dropped and occurs when there is no longer sufficient energy to transport material.
May result in the formation of features such as slip off slopes (on the inner bends of meanders); levees (raised banks) alluvial fans; meanders; braided streams and the floodplain.
Eroded material carried in suspension and solution will be dropped last.
Discharge
Discharge is the volume rate of water flow (velocity), which is transported through a given cross-sectional area. Discharge is normally measured in cumecs (cubic metres a second).
Discharge = cross section of channel (m2) x velocity of water (m/s)
Bed: The bottom of the river channel
Banks: The sides of the river channel.
Channel: The confines of the river, encompassing the bed and two banks.
Wetted Perimeter: The total length of the bed and the banks in contact with the river.
Cross-sectional area: The width of the river multiplied by the depth of the river.
Because the depth of the river will vary across its width, an average depth reading is normally taken. The cross sectional area is normally given in m2.
Velocity: This is the speed that the water in a river is travelling at. The unit of measurement is normally meters a second (m/s). River velocity can be measured using a flowmeter
Channel roughness – as large angular boulders create a rough channel shape and therefore, a large amount of its bed friction.
This creates more resistance to flow than a river with smooth clays and silt forming its banks.
The roughness coefficient is measured using Manning’s ‘n’, which shows the relationship between channel roughness and velocity.
Regimes - variations in a river flow
The regime of a river is expected to have a seasonal pattern of discharge during the year.
This is due to factors such as climate, local geology and human interaction.
Equatorial rivers have regular regimes but in the UK where seasons exist one or two peaks may be recognisable.
Simple regimes: these show times of high water levels followed by lower levels. They exist as a result of a glacier melt, Snowmelt, or seasonal rainfalls such as monsoons.
Complex regimes: if a river has more than one period of high water levels and/or low water levels, this results. It is more common on large rivers that flow through a variety of relief and receive their water supply from large tributaries, for example, the Rhine.
Two types of flow:
Laminar Flow: This rarely occurs, water flows smoothly in a straight channel. It is most common in the lower parts of a river.
Turbulent flow: This is far more common, it occurs where the shape of the rivers channel is varied with pools, meanders, and rapids. A great deal of turbulence results in sediment being disturbed. The greater the velocity the larger the quantity and size of particles that can be transported.
Bradshaw Model
The Bradshaw model, developed by Dr. Anthony D. Bradshaw in the 1980s, provides a framework for understanding the relationships between various factors that influence the morphology (shape and form) of river channels.
This model is especially helpful in analyzing natural, unmodified rivers, although it can also be applied to modified systems with some adjustments.
Key Variables:
Discharge: The volume of water flowing through a channel at a given time. This is the primary driver of channel morphology, with higher discharge leading to wider, deeper channels.
Sediment supply: The amount and size of sediment (sand, gravel, etc.) entering the channel. High sediment supply can lead to braided channels, while low supply can result in meandering channels.
Channel slope: The steepness of the channel bed. Steeper slopes promote faster flow and deeper channels, while flatter slopes encourage meandering and deposition.
Bank material: The strength and cohesion of the material forming the riverbanks. Stronger banks are more resistant to erosion, allowing for steeper channel slopes and narrower channels.
Vegetation: The type and extent of vegetation along the banks and within the channel. Vegetation can stabilize banks, reduce erosion, and influence sediment transport.
Relationships and Interactions:
The Bradshaw model emphasizes that these variables are not independent but interact and influence each other.
High discharge may increase sediment transport capacity, leading to adjustments in channel width and depth.
Channel slope can influence the size of sediment transported, impacting bank erosion and channel form.
Bank material plays a role in how the channel responds to changes in discharge and sediment supply.
Vegetation can modify flow patterns, trap sediment, and influence bank stability.
Hydrographs
The drainage basin system is said to be open as both inputs and outputs of energy and material occur.
All rivers receive a water from it.
The boundaries of the basin are known as the watershed and will usually be marked by areas of higher land.
Drainage basins have many different characteristics that influence how quickly or slowly the main river within them responds to a period of intense rainfall, these are outlined in more detail in the section relating to storm hydrographs.
Physical Factors affecting river discharge:
Impermeable Rock (e.g. granite) - Water is unable to infiltrate through, resulting in more surface runoff, increasing volume of the channel and its speed.
Permeable Rock - More infiltration, resulting in less surface runoff and less volume in the river
Size of drainage basin - Small -> Water will enter the river quicker and faster
Relief of drainage basin - If the slope of the basin is more steep, water in the river is likely to move down faster, increasing its speed
Percipitation - heavy rain can cause saturation in the soil and hence cause more water to reach the river (runoff). This also means that the speed of the river increases.
Vegetation - allows more infiltration and interception, causing less surface-runoff and slowing down the speed of the river
Human Factors Affecting River Discharge:
Impermeable man-made surfaces - Concrete and tarmac can cause rivers in urban drainage basins to have a higher discharge due to higher amounts of surface runoff. Speed is also increased due to drainage systems and ground.
Destruction of vegetation (deforestation) - Less infiltration + interception causes more surface run off and increases speed of the water.
River Management - Presence of dams allow river flow to be controlled, which may cause more discharge (before the dam) , or less (below the dam).
Base flow - the normal day to day discharge of a river
The rising limb - the rapid increase of discharge resulting from a rainfall.
Peak flow - when the river reaches the maximum capacity that it can hold.
The recession limb - when the discharge starts to decrease and river levels fall.
Basin lag time - the time difference between the peak of the rain event to the peak flow.
Factors that affect shape of Hydrograph:
Drainage basin
Type of rock (impermeable or permeable) - Impermeable rock will not allow water to seep in, thus causing larger amounts of surface runoff and a shorter lag time.
The gradient of the drainage basin - Steep gradients will cause greater overland flow and a shorter lag time.
Size of drainage basin - larger basins will take longer to reach the river, hence a longer lag time
Present conditions of the drainage basin - soil either saturated, very dry or even frozen
Shifts and Changes to Curve
Type and amount of Precipitation
Rapid rain - soil will saturate at a very rapid rate, excess water quickly transfers by surface runoff thus causing a short lag time
Land Use and Human Impact
Impermeable man-made surfaces - e.g. concrete and tarmac roads, shorter lag times
Vegetation area -infiltrates more and intercepts water, a longer lag time, reducing discharge
Area of deforestation - short lag time, increases discharge
Time/season of the year
Summer - evapotranspiration rates are higher, reducing surface run off, longer lag time
Temperatures
Water Use
Dams and reservoirs near area - slow down the rate of discharge, a much longer lag time, and may also cause a reduced amount of discharge
Case Study: Floods
Flooding in Rio de Janeiro (2011)
Located in the south east of Brazil and is the capital of Rio de Janeiro state flood started on 11 Jan. and continued for days after floods and mudslides killed over 900 people and lost over 3000 homes which caused $1.3 billion of damage
Much of the state is on the drainage basin of the river Paraiba do Sul - total area of 57000km squared
Human Causes:
Deforestation of hillsides - reduced strength of hills by removing root system, decreases interception and transpiration, which means that soil becomes saturated more quickly (also increase in surface run-off causing landslides)
Building on marginal land - increasing rates of rural-urban migration meant more building on marginal land (includes floodplains and steep slopes unsuitable for settlement building)
No building regulations - informal settlements (favelas) on marginal land, vulnerable during times of flood; most will not have any drainage system, which increases saturation of soil and likelihood of floods
Population density - any flood is going to affect a large population
Poor transport and communication - many poor people received no warning because they had no access to media sources; rescue efforts were also made much more difficult
Physical causes:
Steep drainage basin and valley sides - mountainous areas and steep valleys mean rainfall reaches streams and rivers very quickly causing flash floods
High levels of precipitation
Tropical climate - south east of Brazil experiences over 4m of rain a year, meaning that during the summer, the ground remains largely saturated, thus decreases infiltration rates and increases surface run-off
Mudslides - secondary hazard of flood water; flood water saturated the ground, increases stress on slopes, causing mudslides
Flooding in Bangladesh
Much of Bangladesh has been formed by deposition from 3 main rivers - the Brahmaputra, the Ganges, and the Meghna
Sediment from these and over 50 other rivers form a large delta (80% of Bangladesh is located on the delta, thus under the threat from flooding and rising sea level)
Densely populated (900 people per km squared) and rapid growth (2.7% per annum)
High total rainfall and very seasonal - 75% of annual rainfall occurs in the monsoon between June and September
Ganges and Brahmaputra carry snowmelt waters from the Himalayas
Peak discharges are immense (due to snowmelt in the Himalayas combined with heavy monsoonal rain) - up to 10,000 cumecs
Types of flooding - river floods, overland run-off, flash floods, back-flooding and storm surges
Reasons for flooding:
Discharge peaks of big rivers
High runoff from the Meghalaya Hills
Heavy rainfall
High groundwater tables
Spring tides
Causes and Effects
Outside monsoon season, heavy rainfall cases extensive flooding (leads to destruction of agricultural land); however, may be advantageous to agricultural production due to new source of nutrients
Effects of flash floods due to heavy rainfall in northern India have been intensified by destruction of forest, which reduces interception, water retention and increases rate of surface run-off
Human activity exacerbated the problem - attempts to reduce flooding by building embankments and dikes have prevented the back flow of flood water into the river - leads to a ponding of water (drainage congestion) and back-flooding
Embankments have led to a increase in deposition in drainage channels and can cause large-scale deep flooding
Coastal flooding - storm surges caused by intense low-pressure systems are funneled up the Bay of Bengal
4750 people killed, 130,000 cattle killed, 660,000 hectares of crops damaged
66% of land flooded
23m made homeless
400 factories closed, 11000km of roads damaged, 1000 schools damaged or destroyed
Advantages of flooding:
Flood waters replenish groundwater reserves
Provide nutrient-rich sediment (alluvium) for agriculture in dry season
Provide fish (fish supply makes up 75% of dietary protein and over 10% of annual export earnings)
Reduce need for artificial fertilizers
Flush pollutants and pathogens away from domestic areas
Management Issues and Strategies
Dams and Reservoirs
Dam: a barrier constructed to hold back water and raise its level, forming a reservoir used to generate electricity or as a water supply.
Reservoir: a large natural or artificial lake used as a source of water supply.
Multipurpose scheme: a scheme or project built for more than one purpose. For example to prevent flooding as well as irrigate the land and also generate HEP
Hydrological changes resulting from the construction of dams and reservoirs:
Changes to the hydrology upstream of dams –
Increased evaporation rates because reservoirs have a larger surface area than rivers.
An increase in the amount of surface store (reservoirs are an artificial store).
A reduction in the velocity of the river upstream.
The river was effectively flowing into a stationary store of water.
Increased sedimentation can lower the depth of the river and the reservoir.
Again this will reduce velocity and may also reduce storage capacity.
Changes to the hydrology downstream of dams –
River discharge will decrease because water is being held behind the dam.
A rivers’ discharge may become more regular (less extremes) because the flow of water is regulated.
Clear water erosion may cause the bed of the river to lower.
There is no sediment (load) to be deposited to replace erosion.
The amount of load transported by the river will reduce because less sediment is reaching downstream.
The salinity of the water and the ground may increase.
The temperature of the water may reduce, as water released from reservoirs is often colder (reservoir deeper than river).
The water may also be less oxygenated than natural free flowing water.
With smaller discharge the velocity of the river may decrease, because the level of the river is further below bank-full discharge so the hydraulic radius is smaller.
The amount of depositional landforms may reduce e.g. alluvial fans, levees, deltas and slip off slopes.
Case Study: Dams
Aswan Dam on the River Nile
Built on the River Nile, south of the city of Aswan in Egypt
2 dams - Aswan Low Dam and Aswan High Dam (completed in 1902 and 1970)
Advantages:
Flood and drought control - dams allow good crops in dry years, e.g. 1972 and 1973 in Egypt (reduces dependency on food imports)
Irrigation - 60% of water from the Aswan Dam is used for irrigation and up to 4000km of the desert are irrigated
HEP - accounts for 7000m kW hours each year (45% of Egypt’s energy needs)
Improved navigation upstream and downstream due to less seasonal variations downstream as the amount of water released is regulated (improved tourism on the river Nile)
Recreation and tourism (dam itself is a tourist attraction)
Amount of fishing behind the dam increased, supporting local fishing industry
Building and maintenance of the dam created many jobs and taught local workers new skills
(Estimated that the value of the Aswan High Dam to the Egyptian economy is about $500m each year)
Costs:
Water losses - dam provides less than half the amount of water expected
Salinization - crop yields have been reduced on up to ⅓ of the area irrigated by water from the dam due to salinization
Groundwater changes - seepage leads to increased groundwater levels and may cause secondary salinization
Displacement of population - up to 100,000 Nubian people have been removed from their ancestral homes
Seismic stress - earthquake of November 1981 is believed to be caused by the dam; as water levels in the dam decrease, so does seismic activity
Channel erosion (clear water erosion) beneath the channel; lowering the channel by 25mm over 18 years
Increased sedimentation may put stress on dam, reduce lake depth, storage levels and preventing the nutrients from reaching farmland downstream
Loss of nutrients - $100m worth of artificial fertilizers used annually to replace nutrients (alluvium) trapped behind the dam
Decreased fish catches - sardine yields are down 90% and 3000 jobs in Egyptian fisheries have been lost
Spread of diseases due to increased stagnant water
Floodplain Management
Channel Prosses and Fluvial Forms
Erosion:
Erosion is the wearing away of something. When talking about rivers it normally means the wearing away of the bed, banks and its load. Types of erosion are:
Attrition:
This when load in a rivers flow crash into each other, causing pieces to break off.
Hydraulic Action:
This is when air and water gets trapped in cracks on a rivers beds and banks. The build up of pressure within the cracks causes bits of the bed and banks to break off and the cracks to get bigger.
Corrosion (solution):
When the slight acidity of water cause bits of load and the bed and the banks to dissolve.
Corrasion (abrasion):
When bits of load crash into the bed and banks. This process causes the load, bed and banks to wear away.
Transportation
When a river has surplus energy it may carry some of the material that it has eroded. The different types of erosion are:
Traction: Load that is rolled along the bed of the river.
Saltation: Load that is bounced along the bed of the river.
Suspension: Load that is transported in a rivers’ flow (current).
Solution: Load that is dissolved by a river and then transported by it.
Flotation: Material transported on the surface of a river.
Deposition
When the velocity of a river falls causing its energy to fall.
Because the energy of the river is falling so does its capacity and competence, causing to put down its load. This process of putting down load is deposition.
Hjulstrom Curve: A graph that shows the relationship between river velocity and particle size when looking at a rivers’ ability to erode. transport and deposit.
The Hjulström Curve is a graph used to determine whether a river will erode, transport, or deposit sediment depending upon the flow velocity.
The x-axis shows the size of the particles in mm.
The y-axis shows the velocity of the river in cm/s.
Competence: The maximum diameter of a piece of load that a river can transport.
Capacity: The maximum amount of load that a river can transport.
Critical Erosion Velocity: The minimum velocity that a river needs to be traveling for it to start eroding and then transporting material.
Settling (or fall) Velocity: The velocity that a river needs to fall below to start depositing its load.
What apparent anomaly with the Hjulstrom curve is that it can erode sand at a much lower velocity than it can erode clay and silt.
This is because that clay and silt are very cohesive (they stick together).
This means that even though the particles sizes are small they have a very strong bond between them.
Upper Course
The upper course is nearest the source.
This is where load is biggest and most erosion is vertical.
Most landforms are made by erosion and include; waterfalls, gorges, rapids, v-shaped valleys and interlocking spurs.
Alluvial River: any river that carries load.
Nearly all rivers (except some rivers flowing over ice shelves and glaciers) carry load.
Fluvial: Anything found on or made by a river. This includes all landforms.
Characteristics:
Lowest volume of water
A narrow channel with a steep gradient;
The river erodes downwards.
This vertical erosion results in a number of distinctive landforms including:
V shaped valley cross section
narrow valley floor
interlocking spurs
river's load is of various sizes and angular.
V-Shaped Valley Formation:
Vertical erosion in the river channel
Weathering of the sides of the valley sides
Mass movement of materials down the valley sides,
Material is gradually transported away by the river.
As the river flows through the valley it is forced to swing from side to side around more resistant rock outcrops (spurs).
As there is little energy for lateral erosion, between spurs of higher land creating interlocking spurs
Middle Course and Lower Course:
The middle course when the river leaves the mountains and enters are more hilly environment.
The valley floors starts to widen as you get more horizontal erosion.
The landforms found in the middle course include alluvial fans and meanders.
The lower course is closest to the mouth.
Here the river is travelling over much flatter land and the load is much smaller and smoother.
This is more horizontal erosion here as the river nears its base level.
The landforms found in the lower course include meanders, oxbow lakes, braided rivers, levees and deltas
Meander:
A meander is when water flows in a curvy, bendy path, like a snake.
As a river makes its way through an area that is relatively flat, it often develops bends as it erodes its way through the path of least resistance.
Forms as a watercourse erodes the sediments of an outer, concave bank and deposits sediments on an inner, convex bank (point bar), leading to a meandering channel
Oxbow Lake:
An oxbow lake is a meander that has become cut off from the main river channel.
If you have the outside of two meanders near each other they will eventually connect.
They connect because erosion is at its maximum on the outside of the meander.
When they eventually connect the thalweg (fastest flow) will no longer go around the old meander, but actually go in a straight line.
This means that the outside of the river channel now has a slower flow so deposition takes place cutting off the old meander.
Braided River:
A braided river is a river with a number of smaller channels, separated by small and often temporary islands called eyots.
Braided rivers usually form on rivers with the variable flow (wet and dry season or snow melt season) and high quantities of load.
When a river is at maximum discharge it is able to transport most of its load.
However, when the discharge falls along with the velocity an energy of the river, deposition starts to take place, creating eyots.
Delta:
Form when a river tearing sediment reaches a body of water
Deltas are found at the mouth of a river, where the river meets the sea.
At this point the river is carrying too much load for its velocity and so deposition occurs.
The top of the delta is a fairly flat surface.
This is where the coarsest river load is dropped.
The finer particles are carried into deeper water.
The silt is dropped to form a steep slope on the edge of the delta while the clay stays in suspension until it reaches the deeper water.
Levees:
Levees are embankments found on the sides of a river channel. Levees can be made by or enlarged by humans, but we are only interested in levees that are made naturally.
Levees are made when a river exceeds bankfull discharge i.e. it is in flood.
Floodplain:
The floor of the valley floor that gets flooded when a river exceeds bankfull discharge.
Floodplains tend to be much wider in a rivers’ lower course where horizontal erosion has had a greater effect.
Bluff line:
The outer limits of the floodplain.
The bluff line is basically the edge of the valley floor.
Strand line:
A line of load (usually sticks and litter) that is deposited at the limit of a flood.
Alluvial deposits (alluvium):
Load that is deposited by a river in time of flood.
Floodplains and leveés are formed by deposition in times of river flood.
The river’s load is composed of different sized particles.
When a river floods it deposits the heaviest of these particles first. The larger particles, often pebble-sized, form the leveés.
The sands, silts and clays are similarly sorted with the sands being deposited next, then the silts and finally the lightest clays.
Every time the river floods deposition builds up the floodplain.
Meanders & Oxbow Lakes
deposition and erosion
Floodplains, Levees & Deltas
deposition
The river is now flowing over flatter land and so the dominant direction of erosion is lateral (from side to side).
The river has a greater discharge and so has more energy to transport material. Material that is transported by a river is called its load.
Deposition is also an important process and occurs when the velocity of the river decreases or if the discharge falls due to a dry spell of weather.
Materials Transported Downhill:
Traction: boulders and pebbles are rolled along the river bed at times of high discharge
Saltation: sand sied particles are bounced along the river bed by the flow of the water
Suspension: Find clay and sans particles are carried along within the water even at low discharges
Solution: some minerals dissolve in the water (Ex. Calcium carbonate). THey require little energy
Case Study: Floodplain Management
River Conwy, North Wales - Floodplain Management
Source in Snowdonia and mouth in the Irish Sea
Only 27 miles long but has regular floods
Steep gradient and sits on impermeable slates (little infiltration, high rates of surface run-off)
Weather near source is very wet, receives up to 4m of rainfall a year
During spring, the river is also fed by snowmelt
Deforestation and tidal rivers make it very prone to flash floods
Flood in 2005 damaged railways, roads, farmland, parkland, houses and businesses
Management techniques used:
River wall - a 3m concrete wall built to protect the village of Llanrwst
River training - rocks placed in river channel to slow river near village and cause deposition (redirected away from village)
Channelization - little tributaries that flow through Llanrwst have been lined with concrete; aim is to get water through the villages quicker by reducing friction
Embankments levees - raised banks built along river sections to increase river’s cross-sectional area and reduce flood risk
Raised buildings and pathways - built on stilts so they don’t get damaged if river bursts its banks
Controlled flooding - low value farmland allowed to flood to protect high value settlements
Flood proofing houses - designed with no carpets and removable furniture on lower floors
Human Modifications to Floodplains
Urbanization: Urbanisation tends to cause deforestation reducing interception and transpiration. Sewers also reduce surface stores and therefore evaporation. Urban areas usually create large impermeable surfaces which can lead to greater surface run-off.
Sewer Systems: Generally sewer systems create artificial channels, which often reduces a rivers’ lag time and can lead to increased flooding downstream.
Pollution: Transport, industry and housing all create pollution which works its way into the water system. Areas that don’t have proper sewers and water treatment tend to be effected more. Metals and chemicals are particularly polluting.
Water table (groundwater depletion): Unsustainable use of groundwater can cause subsidence.
Mexico City has experienced subsidence because of aquifer depletion underneath the city. On the scale, London has actually seen its water table rise since deindustrialisation has meant the demand for water has fallen.
Deforestation: Deforestation reduces interception and transpiration. Removal of trees can also increase the risk of mudslide by reducing slope stability and stops root uptake. Less interception speeds up the rate the ground become saturated and therefore increases the risk of flooding
Micro-climate: Urban areas create heat islands which can increase convectional rainfall. Particulates released by industry and transport also make excellent condensation nuclei.
Channelization: Artificially smoothing channels may remove river discharge from one area, but areas down stream that haven’t been smoothed are likely to experience an increase risk of flooding.
Alternative Stream Management Strategies
Channel Enlargement (widening/deepening): Making the width and depth of the river wider and deeper to increase its cross- sectional area.
Advantages: By enlarging the cross-sectional area you are increasing the bankfull discharge of the river along with its hydraulic radius.
This will increase the velocity of the river and reduce the chances of it flooding in the immediate area by moving the floodwater further on downstream.
Disadvantages: If buildings are built up to the river bank it might not be possible to enlarge the channel.
Also the process can be expensive and can cause problems to areas downstream who are receiving more flood water quicker, but with an un- enlarged channel.
Channel Straightening: Removing meanders from a river to make the river straighter.
Advantages: By removing meanders the velocity of the water through a settlement will increase.
This will stop a backlog of water and should reduce the risk of flooding. It also improves navigation.
Disadvantages: By changing the course of the river, you might remove flowing water from industries that depend on it.
There might also be building that have to be demolished to allow straightening.
Again it is expensive and may cause flooding problems downstream.
Flood Relief Channels: Building new artificial channels that are used when a river nears bankfull discharge.
Advantages: They take the pressure off the main channels when floods are likely therefore reduce flood risk.
Disadvantages: It can be hard find land to build relief channels, they are expensive and when empty can become areas to dump rubbish, etc.
If river levels rise significantly it is also possible for relief channels to flood as well
Artificial Stores: Creating reservoirs or lakes that can store excess water in times of flood.
Advantages: They can remove pressure of the main channel and can become new habitats and serve other purposes e.g. leisure, drinking water.
Disadvantages: Building dams, sluices, diversion channels are all expensive.
They also involve flooding areas of land which may be hard to find near large vulnerable urban populations
Flood Embankments (levees): Like levees these increase the channel depth of a river, raising its bankfull discharge and reducing the risk of flood.
Advantages: They increase the cross-sectional area of the river and therefore its hydraulic radius.
This should reduce the risk of flooding.
Disadvantages: Like in New Orleans under extreme conditions, embankments may fail causing even bigger problems.
They are expensive to build and again may cause problems downstream.
Controlled Flooding: Allowing low value land e.g. farmland to flood, therefore protecting higher value areas.
Advantages: By allowing the river to flood naturally you are taking the pressure of high value areas, you are letting the river behave more naturally and it adds alluvium to the floodplain.
Disadvantages: You have to make the decision what is worth protecting which is always going to upset someone.
You also have to protect areas that you don't want to flood which costs money (cost benefit analysis)
Afforestation / Reforestation: Simply planting more trees in a drainage basin.
Advantages: This is a natural process, increasing the amount of interception, transpiration and root uptake.
People would not normally protest against trees being planted.
Disadvantages: It is not possible to cover the whole drainage basin in trees, so if it rains in an area with no trees, then there is no reduction in flooding.
Also, most trees lose there leaves in autumn and winter reducing interception in those months.
Flood Proofing: This is making property less vulnerable to flooding or flood damage. This might be temporary like using sandbags or design by removing carpets downstairs.
Advantages: This can be done on an individual level and can be relatively cheap.
Temporary protection can be removed under normal circumstances so it does not change the aesthetics of properties.
Disadvantages: Temporary defences can usually only protect against minor floods.
Not everyone will be happy with having to redesign their houses.
Insurance: Although it doesn't prevent flooding, it can help individuals and industries to recover and protect against future flooding.
Advantages: It helps individuals and settlements to recover after flood events and may help them protect property and be less vulnerable in the future.
Disadvantages: They do not actually prevent flooding.
Not everyone can afford insurance and insurance companies may not insure high risk areas.
Land Use Planning (zoning): Mapping areas by looking at there likelihood to flood and then only building low value uses on areas with high flood risk.
Advantages: Very good at removing high value areas and high density populations from hazardous areas.
Disadvantages: It is not always possible to change land uses that already exist in an area.
You have to decide what size flood to map for e.g. a once in ten year flood or once in one hundred year flood.
Often poor will still choose to live on marginal land.
Contour Ploughing and Strip Cultivation: Either creating temporary surface stores or leaving vegetation to increase interception and transpiration
Advantages: Contour ploughing is simply a cheap and easy change in existing farming methods.
Keeping vegetation is natural and relatively cheap.
Disadvantages: Won't protect against big floods and farmers may not be happy giving up farmland, simply to grow trees.
Interception Channels: These are channels that divert a rivers' discharge around settlements.
The old channel remains but with a smaller discharge.
Advantages: They remove pressure of the main river and areas of high land value.
They may also develop into new habitats for plants and animals.
Disadvantages: They are expensive, may flood themselves in times of heavy floods and may restrict future urban
Settlement Removal: Moving settlements from high risk flood areas to less vulnerable locations often on higher land.
Advantages: Is probably the most effective because you remove high value property and humans from vulnerable areas.
Disadvantages: It is usually not practical to move whole settlements, because of the cost and the problems of finding alternative locations.
Also many settlements depend on water for their survival.
Dams: Often built as part of a multipurpose scheme, they create artificial stores which can hold water in times of increased precipitation.
Advantages: They can store large amounts of water and can be used for other purposes.
Disadvantages: If rain is downstream of the dam then they have no effect.
In large flood events they are vulnerable to breaking and are expensive to build.
Wing Dykes: Barriers placed out into a river, these can be used to divert the cause of rivers by shifting the thalweg of rivers.
This may move the channel away from high value areas.
Advantages: They can move the main channel from vulnerable areas to protect high value areas.
Disadvantages: They are expensive to build and during big flood events the flood water may go over the wing dykes.
Also if there is property on both sides of a river, which side do you protect.
Electronically Controlled Sewers: Advanced sewers which can control the flow of rain water tostop increased discharge into rivers and therefore flooding.
Advantages: They can be very effective at controlling smaller floods.
They are underground so do not cause any visual pollution.
Disadvantages: This involves a complete redesign of sewers.
Sewers usually have to be increased in size and electronic sluices have to be added.
They also have to be operated from a central command centre and with all electronically operated equipment can break.
Also they might not be able to cope with large scale floods, so water has to be released into rivers anyway.
Channelization: The concreting of beds and banks.
Advantages: Reduces friction and increases velocity of river, removing water from the channelised area quicker.
Bank erosion is also reduced.
Disadvantages: It is expensive and is not natural so vegetation and animal life will find it harder to grow and live.
Flooding maybe caused downstream of the channelised area.
Dredging: The removal of material from the bed of the river deepening it.
Advantages: Channel cross-section is increased so the river can hold greater discharge.
It can look more natural because no structures are built.
Disadvantages: Deposition can mean that dredging needs to happen regularly.
River bank conservation: Protecting the banks and sides of the river to reduce erosion.
This can be done through planting vegetation.
Advantages: It looks natural, promoted wildlife and is relatively cheap compared to hard-engineering.
Disadvantages: During large flash floods vegetation can be easily removed.
River restoration: Returning a river to its natural state before it had been managed. This might involve removing channelization.
Advantages: This looks natural, is attractive and can attract wildlife. Can allow the floodplain to become more fertile.
Disadvantages: Can't protect against big floods and may have to coincide with zoning
Groundwater Management
Key Terms
Artesian basin: An artesian basin or aquifer is a confined aquifer containing groundwater under positive pressure.
This causes the water level in the well to rise to a point where hydrostatic equilibrium has been reached (balance between pressure on the aquifer and pressure from the aquifer).
Aquifer: Rocks that can hold water.
Saturated: When all pore space is full and rocks or soil can hold no more water.
Groundwater: Water held under the surface of the earth.
Depletion: When something is reducing, aquifers can become depleted in dry periods or when they are managed unsustainably.
Aquiclude: Rock that will not hold water or allow its movement. i.e. they are non-porous and impermeable
Causes of Groundwater Usage:
Evapotranspiration from shallow stores, capillary action will draw moisture up to near the surface
Natural discharge by springs and into lakes, rivers and oceans
Artificial abstraction (removal) for domestic, industrial and agricultural use
Leakage into nearby aquifers
Interbasin transfers
Causes of Groundwater Recharge:
Artificial recharge. Either leakage from irrigation channels and reservoirs or the pumping of water into aquifers.
Infiltration and percolation after precipitation or snow melt
Seepage from river channels, lakes and oceans
Leakage from nearby aquifers
Interbasin transfers
Case Study: Groundwater Management
Groundwater Pollution in Bangladesh - Groundwater Management
Increase in incidence of cancers in Bangladesh
Caused by naturally occurring arsenic in groundwater pumped up through tube wells
As many as 85m of the country’s 125m population will be affected by arsenic-contaminated drinking water
UNICEF has sunk millions of tube wells in Bangladesh, providing a convenient supply of drinking water free from bacterial contamination of surface water
But the water from wells was never tested for arsenic contamination, which occurs naturally in the groundwater
1 in 10 who diners water containing arsenic will ultimately die of lung, bladder or skin cancer
Arsenic poisoning is a slow disease - skin cancer occurs 20 years after people start ingesting the poison, then internal cancers
One solution is a concrete butt, collecting water by pipe from gutters
Another is a filter system
Freshwater Wetland Management
Wetland is an area of land where soil is saturated with moisture either permanently or seasonally.
Such areas may also be covered partially or completely by shallow pools of water. Wetlands include swamps, marshes and bogs.
The water found in wetlands can be saltwater, freshwater, or brackish (a mixture of fresh and salt water).
The world’s largest wetland is the Pantanal which straddles Brazil, Bolivia and Paraguay in South America.
Brackish water: Water that has a higher salinity content than freshwater, but not as high as saltwater.
Importance of Wetlands
Flood control:
Many wetlands are covered in vegetation which can intercept precipitation, absorb rainwater and transpire water.
Wetland vegetation can also reduce the velocity of rivers flowing into them or from them and act as natural stores of water.
If you remove or drain areas of wetland more pressure is placed upon the main river channel.
Coastal and marine wetland areas can also absorb the energy of tropical storms, tsunamis etc.
Groundwater recharge:
Wetlands can collect large areas of precipitation and river discharge.
As this water is held in storage it will infiltrate and percolate into the ground to recharge groundwater.
Transport Network:
Wetland provide many natural waterways that people can move around on easily.
Tourism and Leisure:
Some wetlands, like the everglades in Florida or the fens in East England become tourist attractions.
They also become popular locations to bird watch, fish and hunt.
Flora and Fauna:
Many wetlands are unique habitats that support indigenous aquatic plants and animals.
Many wetlands support rare reptilian and amphibian species.
Many migratory birds also rest in wetlands flying to and from nesting and breeding grounds.
Fisheries:
Wetlands can support large numbers of fish which can support local populations.
Wetlands are not normally viable commercial fisheries.
Water purification:
The soils, geology and vegetation of wetlands can help clean and purify water.
Storage of organic matter:
Wetlands support large areas of organic matter that can hold large stores of methane (greenhouse gas).
Coastal stabalisation:
Wetlands that occur along the coastline and on river banks have prevent erosion from the sea or by rivers.
Factors Causing Loss and Degradation of Wetlands
Increased demand for agricultural land:
As the world population grows there is an increasing demand for food.
With the amount of viable agricultural land decreasing, increasingly areas of wetland are being artificially drained to make ways for agricultural land e.g. the draining of the fens in East England.
Population growth:
As the world’s population grows, it demands more water, more food and more land.
The increasing demand for water can mean wetlands are drained of their water or their source of water.
This problems is made worse as the world’s population develops and uses more water e.g. showers and toilets.
Urbanization:
With the world population growing, there is a greater demand for housing. Increasingly this demand for housing is in urban areas.
With urban areas growing more and more wetland areas are being drained or inhabited.
Urbanisation on or near wetlands can cause pollution, changes in river flow and river channels and disturbance of wildlife.
Land reclamation is the process of reclaiming land from the water.
Sea level rises:
Global warming is causing glaciers and ice sheets to melt causing sea levels to rise.
These rising sea levels can flood coastal and marine wetland areas.
Even if the whole wetland is not flooded, water conditions can be changed from fresh to brackish.
River flow changes:
Many rivers have been channelised and straightened, reducing the amount of wetlands.
Others have been drained or dams have altered flow.
Some have been polluted or redirected.
All these natural changes are removing or changing the ecosystems of many wetland areas.
Pollution:
Any form of pollution, but particular chemicals and metals can change the delicate ecosystems of wetlands.
Process like eutrophication, caused by fertiliser run-off can completely kill whole wetland areas by preventing the wetland oxygenating properly and receiving sunlight.
Infrastructure projects:
As populations grow and we become more mobile, there is an increasing demand for new roads, airports, railways. etc.
Unfortunately wetlands are often drained or disrupted (bridges, dykes and causeways) to make way for these projects.
Alien species invasion:
Many alien species like the cane toad in Australia or the American mink in the UK have been introduced to wetlands and devastated indigenous species.
The introduction of any alien, however small can disrupt food webs and ecosystems.
Tropical storms:
Although wetlands can be a natural defence against tsunamis and tropical storms, they can also been damaged by them.
Freshwater wetlands in particular can be flooded by storms surges associated with tropical storms, changing the salinity of water and damaging vegetation.
Case Study: Wetland Management
Kissimmee River - Wetland Management
In south central Florida, drainage basin of 7800km squared and approximately 200km long was home to wetland plants, fish and wading birds.
However, the 5km wide floodplain with populated settlements nearby were regularly flooded.
Thus, the river was channelized and transformed into a 90km, 10m deep drainage canal - to provide an outlet canal for draining floodwaters from upper Kissimmee lake basin and to provide flood protection for land adjacent to the river
Impacts of channelization:
Loss of 12000-14000 hectares of wetlands
Floodplain dried up after channelization - no longer exceeds bankfull discharge
Egret, heron, and wood stork populations decreased by ⅔
Catches of largemouth bass decreased
Fishing, bird watching and hunting tourism declined
Concerns about the sustainability of existing ecosystems led to the Kissimmee River Restoration Project (large scale, supported by the state and federal)
Aim: restore over 100km squared of river and wetland floodplain by 2015
Started in 1999
River is being de-channelized by refilling the flood canal and re-establishing the old natural course of the river
Restored sections now flood naturally - restored floodplains could benefit avian species e.g. wading birds and waterfowl, by providing increased feeding and breeding habitats
Dissolved oxygen levels have doubled in restored sections
Increase in revenue from tourism potential could significantly enhance local and regional economies
Possible negative impacts from restoration:
Greater evaporation due to more surface stores
Increase risk of flooding
River will be less navigable in dry periods
Restoration will cost $578m
Agriculture and Irrigation
Agriculture:
Agriculture the artificial cultivation (growing or rearing) of plants or animals.
Agriculture that grows crops is known as arable agriculture, agriculture that involves rearing animals is known as pastoral agriculture.
Irrigation:
This means artificially watering the land.
There are three main types of irrigation; gravity flow, sprinklers and drip systems.
Eutrophication:
This is the processing of artificially adding nitrates and phosphates (through fertilsers and sewage) to wetland areas e.g. rivers and lakes.
The added nitrates and phosphates causing excessive growth of algaes.
The algae growth can reduce the oxygen content of the water as well as reducing the amount of sunlight that it receives.
The nitrates and phosphates often come from agro-chemical run-off, but can also come from domestic sewage and industrial waste.
Salinisation:
This is the increase in the salt content of water.
Salinisation can happen because of evaporation or unsustainable water extraction.
If the water become to salinated it becomes less fertile.
Growing Demand for Agricultural Products:
The world’s population is growing.
The current population is about 7 billion, but it is expected to peak at nearer to 9 billion.
Because fossil fuels are finite, alternative forms of energy are being looked at.
One form of renewable energy being used are biofuels.
Biofuels are made out of biological matter and therefore are increasing the demand for agricultural products.
Economic development.
As more of the world’s population is removed from poverty, their calorific intake increases.
This increase in food consumption, is increasing the demand for agricultural products.
Pastoral farming.
As the world population increase, the demand for meat also increases.
Most farm animals are omnivores or herbivores so need agricultural products like corn to eat.
Decreasing Supply of Agricultural Products or Land
Urbanisation.
As the world develops, urbanisation increases tends to happen increasing the size of urban areas.
As urban areas grow they eat into greenfield sites in rural areas, reducing the amount of agricultural land.
Land degradation and desertification.
Land that is overcultivated or overgrazed can become degraded (less fertile).
As farmers try to react to demand by growing more intensively, more land is being degraded.
In extreme circumstances, the land may turn to desert (desertification).
Rising sea levels.
Some of the earth’s most fertile agricultural areas are floodplains and deltas.
As world sea levels (eustatic changes) increase much of this fertile land is lost.
Conversion to biofuels.
Although not strictly reducing the amount of agricultural products (biofuels are agricultural products), this does decrease the supply of agricultural products available for human consumption.
Biofuels are often favoured by farmers, because they demand a higher price.
Hazards.
Natural hazards like tropical storms, volcanoes and tsunamis can reduce the amount of agricultural land available for cultivation.
Disease.
There is an increasing amount of intensive monoculture (growing of one crop) taking place.
Monoculture always runs the risk of been impacted by the outbreak of diseases or pests that attack the particular crop e.g. wheat leaf rust fungus.
Competing Demand for Water
Competition on Local Scale
Case Study: Local Scale Competition for Demand for Water
Israel’s Aquifers - Demand for Water: Local/national Scale
Water is one of the most sensitive and unsolvable problems in the Middle East
Created friction between the Arabs and Jews (Israeli-Palestinian tensions)
For decades, Israel has obtained up to 80% of the 670m cubed of water provided by mountain aquifer mostly located under the West Bank
Israelis have occupied the West Bank since 1967 and have prevented the Palestinians from obtaining better access to the resource
Mountain aquifer is important for Israel as it provides:
⅓ of its water consumption
4% of its drinking water
50% of its agricultural water
120,000 Jewish settlers in the West Bank use 60m cubed annually compared to 137million m cubed used by 1.5m Arabs
The WB and Gaza are served by Israel’s water carrier and groundwater in aquifers
WB’s aquifers, replenished by rainfall, flow west, north, and east from the watershed
Palestinians were forbidden to dig new wells or deepen old ones (Israel claims that they have the right to use the aquifer because some of the water flows into its territory) - thus kept very short for their crops
The Gazans, like West Bankers, get little domestic water from Israel’s national carrier - most of their supplies come from an aquifer that has been exploited - Gazans pump twice as much as can be safely withdrawn, leading to salt water intrusion (kills citrus trees)
Gaza Strip is part of the Palestinian territories - coastal aquifers becoming exhausted and at threat of salt water intrusion and domestics and industrial pollution
Competition on International Scale
Case Study: International Scale
The Mekong - Demand for Water: International Scale
South-east Asia’s largest river flat, well-watered and fertile land in the basin lies around Tonle Sap Lake, but annual flood makes intensive agriculture difficult there surface area of lake can increase up to ten times during the monsoon remained untouched until 1990s
First dam non the river, at Man Wan, in China was completed in 1993
Population growth and economic growth - place strain on the Mekong
HEP potential of the Mekong and its tributaries is considerable - so far, only 5% of the lower basin’s HEP have been developed
Dams generate electricity, aid irrigation and regulate flooding
However, caused damage to fisheries - annual harvest amounts to 2m tonnes
Case Study: International Scale
The River Nile - Conflict at International Scale
Importance of the River Nile:
Tourism - rapids in Uganda
agriculture and irrigation - Egypt depends on the Aswan Dam to irrigate the desert
Transport - promote trade
Wildlife
Drinking water
HEP - drought control
Longest river in the world, 6650km long
2 main tributaries - White Nile and Blue Nile
Confluence is in the Sudanese capital, Khartoum
Source of WN: Burundi
Source of BN: Ethiopia
WN, BN and the Nile flow through 11 countries
Conflicts:
Have arisen since Ethiopia began dam building
In 2010, 6 of 9 upstream countries signed a Cooperative Framework Agreement seeking more water shares from the Nile
Sudan and Egypt rejected agreement because it challenged their historic water allocations
A major dam on the BN, called the Grand Renaissance Dam is under construction by Ethiopians
Egypt, draws much of its drinking water, natural resources, and energy from the Nile, has protested the dam’s construction (will siphon resources away)
Dispute between Egypt and Sudan over the dam construction has reignited a 60-year old dispute (Sudan, downriver of the Nile, has supported Ethiopia’s attempts to build the dam)
Ethiopia denies that the dam would damage Egypt’s water supplies
Egypt now hope to pull the Europeans to its side ad to pressure Ethiopia before protesting before the security council
Egypt has threatened to defend its historical claims over the Nile in numerous occasions - it will even use air power against other countries to protect its flow of the Nile
Oceans and Coastal Margins
1. Introduction to Ocean Currents
Ocean Currents: surface ocean currents are caused by the influence of prevailing winds steadily blowing across the sea
Gyres Ocean Currents: the dominant pattern of surface ocean currents which is roughly a circular flow. This is clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere due to the Coriolis Force due to the Earth’s rotation. The only expectation is the circumpolar current around Antarctica
Gulf Stream Ocean Currents: Narrow flowing current which is the return flow of westward piling water, caused by the circulation of gyres and the Earth’s rotation)
transports heat northwards and then eastwards across the North Atlantic
creates mild winters & cool summers in the British Isles
Transfer of Nutrients and Energy:
Nutrient Transfer due to Ocean Currents: eastern oceans experience upwelling currents, where the ocean currents move nutrient-rich cold water from the ocean flow to the surface
Energy Transfer due to Ocean Currents: Warm currents from regions near the equator raise the temperature of the polar area, while cold currents may reduce summer temperature when the wind blows from sea to land
Specific Heat Capacity: the amount of energy needed to raise the temperature
Takes more energy to heat water than land
Coastal regions are cold during the day and mild at night
The Pacific Ocean
Two atmospheric states: are warm surface water in the west and cold surface water in the east (and vice versa). Warm surfaces cause low pressure, and as air blows from high pressure to low pressure, it causes a movement of water from colder areas to warmer areas
Ocean Conveyor Belt/Thermohaline Circulation (THC): a global thermohaline circulation driven by the formation and sinking of deep water and responsible for a large flow of upper ocean water
Thermocline: the boundary between 200-800m below which the surface waters do not mix with deeper layers; region marked by rapid discrete in temp as depth increases
Halocline (salinity) and Pycnocline (water density): both increase with increasing depth.
Halocline exists in the same depth as thermocline
Salinity rapidly increases and temp decreases, which leads increase in water density
marked by proc line
El Nino vs La Nina:
El Niño: a reversal of the normal atmospheric circulation in the southern Pacific Ocean, beginning arm water and low pressure to the eastern Pacific, and cool water and high pressure to the western Pacific
Occurs once every 2-10 years and lasts 12-18 months
La Niña: intensification of normal atmospheric process
The cold current that flows from the east across the equatorial Pacific Ocean
Occurs when low pressure in the western Pacific becomes even lower
Hurricanes:
Hurricanes (Tropical Cyclones): low-pressure systems; high-intensity rainfall, strong winds, & heavy waves (flooding & mudslides).
Originate from moist, tropical seas; erratic path; winds spiral rapidly around the calm area (eye); pressure contrast = strong gale-force winds.
Move excess heat from low latitudes to higher latitudes; begin as small-scale tropical depressions (low pressure, warm air rises).
Sea = temp. above 27°C and a depth of 60 m; low-pressure area far from the equator (Coriolis force rotates rising air mass); unstable conditions.
Saffir-Simpson scale = assign hurricane to 1 of 5 categories of potential disaster; based on wind intensity; formed in Atlantic and Pacific
Case Study:
Typhoon Haiyan, Philippines
winds of 314 km/hr
10 000 ppl killed & buildings were destroyed
sea waters rise 6 m
World Food Programme = $2 million in aid
economic cost = $15 billion (many countries pledged aid)
vulnerable community (no savings)
Ocean Role and Acidification:
Ocean Acidification: freshwater = pH of 7 & surface seawater = 8.2 (dropped to 8.1) ; absorption of CO2 by oceans ; 0.1 difference = inc. of 30%
Absorbed 50% extra CO2 during the industrial age; anthropogenic causes (human actions); threatened species (fisheries & coral reefs).
30% of human-made carbon absorbed by oceans; reacts and turns into carbonic acid - reducing calcification of organisms (growth rate Dec. 14%).
Pacific coast = failure of commercial oyster; Great Barrier Reef = coral bleaching; Poles / high latitudes = shellfish (pteropod) reduction
Oceans as a Source and Store of Carbon Dioxide: largest CO2 sink (90% of carbon); carbon on ocean floor lifted (thermohaline circulation) = source.
Cold glacial phases = atmospheric CO2 decreased, stored in oceans ; Warm interglacials = CO2 released from oceans (inc. atmospheric CO2).
CO2 reservoirs = fossil fuels, atmosphere, & oceans ; carbon cycle (photosynthesis produce CO2 & released by volcanic activity, long timescale)
2. Interactions Between Oceans and Coastal Places
Coastal Environments: influenced & shaped by physical and human processes
Lithology Properties (rock); Geological Structure (concordant coastline = geological strata is parallel to the coastline, discordant = perpendicular);
Processes (erosion, deposition);
Sea-Level Changes (interact w/ processes, advancing/retreating coastlines);
Human Impacts;
Ecosystem Type
Waves: wind blowing over the sea surface, tides, or earthquakes (tsunamis); controlled by wind strength & duration, the distance of open water, & depth
Swell waves = open water, travel huge distances, long wavelength, reduced height; Storm waves: destructive waves, local winds, short distance.
Swash = movement of water up the beach (energy transferred to the shore); Backwash = movement of water down the beach, gravity.
Wave Refraction: approach an irregular coastline; refraction reduces wave velocity - wavefronts break parallel to the shore (if refraction is completed).
Concentrate energy onto sides of headlands and dissipate energy in bays
Sediment Supply: littoral cell system (coastal sediment system) - coastal processes & patterns in an area, simplified; input & output balanced.
Dynamic equilibrium: any system = inputs & processes w/in the cell; change in input affects processes & resulting change in landforms
Lithology: characteristics of rocks (resistance, bedding, jointing, permeability); well-developed jointing = cliff, wave erosion (finds weakness)
Composite cliff = more than one rock type; shape & form of cliff depends on strength and structure (impermeable versus permeable rock).
Subaerial and Wave Processes: operate on coastlines & produce landforms.
Weathering: Salt (sodium compounds expand joints), Freeze Thaw (water freezes & expands), Water Layer (tidal cycle), Biological (organisms).
Erosion: Abrasion (tiny particles), Hydraulic Impact (force of water), Solution (acidic water dissolves rock), Attrition (large rocks collide & erode)
Features of Erosion: bays (hard rock = headlands, weak rock = eroded to bays) ; Bayhead beaches = constructive waves, deposit sand b/w headland
Faults erode into sea caves; arch = two sea caves meet; stack = roof of arch collapse (further erodes into stump); energy of wave refraction
Wave-cut (shore) platforms: intertidal, high-tide, or low-tide; high-energy; cliffs eroded to lower-angle cliffs; subaerial processes
Cliffs: depend on geo. Structure and subaerial & marine processes; low resistance rocks = easily eroded, can’t support overhang.
Features of Deposition: requires a large supply of material, longshore drift, irregular coastline, low-energy, & bioconstruction.
Storm waves = winter, Swell waves = summer; destructive waves = reduced beach angle; small sediment = reduced impact of swash & backwash.
Spit: the beach of sand linked at one end to land; indented coastlines or river mouths; thin attached end (proximal end) & larger end (distal end).
Curved, waves undergo refraction; longshore drift = moves sediment along the coast, and irregular coastline = refraction (waves bend).
Beaches & Sand Dunes: large dunes = mid-latitude, storm waves (sand supply, high onshore wind speed, low precipitation & humidity)
The tidal range exposes sand (eroding rivers); free dunes (no vegetation, desert), embedded dunes (vegetation trap sand, humid areas)
Case Study: The Palisadoes, Jamaica; largest deposited coastal system in the Caribbean (13 km, 4000 yrs old)
Longshore drift = east to west provides sediments; located at a sharp bend in coastline (sediment carried westwards); extends the length of the spit
Spit grew longer and linked with small islands (cays); forming a tombolo; an area vulnerable to natural disasters (tropical storms & hurricanes)
Advancing and Retreating Coastlines: isostatic change = localized change in level of land relative to sea level; rise = tectonic uplift (remove ice)
Global warming (enhanced greenhouse effect) raises sea levels, impacts low-lying communities
Retreating = rate of erosion exceeds the rate of deposition (submerged coasts); Advancing = rapid deposition (emerging coasts).
Coastal Processes, Wind, & Vegetation in Sand Dune Development:
Sand moved by wind (up to 1 mm); grains above 1 mm = saltation (move by turbulence); irregular = inc. wind speed, more sediment moved
Shore = soil contains few nutrients, mostly sand, “yellow dunes”; vegetation needed for stable dune (dec. wind speed, deposition can keep up)
Reduce wind speed = less evapotranspiration loss (moist soil, decaying marram add nutrients to soil - more acidic)
Slack (low points b/w dunes) = moist conditions; marsh vegetation; rear of dune system = “grey dunes” - humus in soil
Many shells = calcium, form grasslands; calcium leached from old dunes = acid dunes (outwash of sand and gravel)
3. Managing Coastal Margins
Coastal Erosion and Flooding Management Strategies:
Human pressures = need for coastal management; prevent coastal erosion & flooding by sea; inc. pressure = inc. pop. & temp.
Defense options: do nothing, maintain existing defense, improve defense, manage retreat (protect some areas, let others erode)
Hard engineering = man-made techniques; Soft Engineering = working with nature to protect the coast (offshore reef, beach nourishment)
Cliff defenses: cliff base (sea walls, attempt to absorb the energy of waves, protect from erosion), cliff face (cliff drainage, make cliff less steep)
Norfolk, UK: Major energy development at the gas terminal at Bacton; protected by gabions & concrete blocks
Cost-Benefit Analysis of Coastal Defence: costs of building & maintenance, reduced beach access; protection buildings & rising land price.
New York: Superstorm Sandy in 2012; 14 ft storm surge; defences = 12 ft; $20 B in damages versus $19 B for new defecses
Fukushima-Daiichi tsunami: 2011; surges over 11 m; overt topped 10 m high sea walls
Case Study: Palisadoes spit; storm surges & coastal flooding led to erosion of dune; Jamaican gov. = repair degraded shoreline (cost $65 M).
Rock revetment walls, Caribbean; road - 1 m to 3.2 m above sea level; drainage facilities (excess water); 10 m boardwalk
Case Study: Thames Barrier; 1982, £500 M; protect London from flooding (flood risks rising - sea level rise & subsidence); used 7 times per year.
Conflicting Pressures on Coastlines: the Soufrière Marine Management Area (SMMA); 1995; stewardship resource management approach.
Conserve and protect the marine environment. & sustainable development (fishing & tourism); 11 km of coastline, 5 zones (cater to various uses)
Central west coast of the Caribbean island of St. Lucia; submarine shelf, supports reeds; fishermen competing w/ tourism-related users.
1980s: expand tourism sector; conflicts - inc. competition b/w fishers and yachters, use of fishing areas & reefs.
SMMA = new zoning plan (fishing priority areas, reserves, multiple-use areas); management measures (user fees, incentives).
1997: difficulties in implementing SMMA; involve stakeholders; inc. fish caught & fish biodiversity; less damage to coral reefs
Top-down approach (rules & regulations established w/o public consult); lack enforcement capabilities (limited financials) - SMMA helped
Beaches = target for illegal sand-mining; solid waste from land- and water-based sources; construction infrastructure (affect nature)
Managing Coral Reefs: 25% of species interact w/ coral; temp. above 18°C & below tropics, low acidity & sedimentation; water = 5-30 m
Biological & economic importance (tourism, Great Barrier Reef = $4.6 B); the global value of reefs (fishing, tourism & coastal protection) = $375 B
Advantages: biodiversity (breeding ground), seafood (LIC = 25% of fish catch), medicine (chem. from organisms, bone graft)
Coastal protection: reefs buffer adjacent shorelines from wave action & storm impact; maintain mangrove fisheries & wetland, support econ.
Pressures on coral: human activity (overfishing, tourism, pollution); greenhouse gasses - ocean acidification & coral bleaching
World Resources Institute: 60% of reefs = immediate threat (50 yrs to 2016 = lost 25% of corals); global conservation measures.
Marine Protected Areas (MPAs): status to eco. sensitive areas; restrict harmful activities; 10% of marine areas under conservation.
USA’s National Oceanic & Atmospheric Administration (NOAA); uses drones; to track fishing vessels & monitor temp.
Managing Mangrove Swamps: salt-tolerant forests; grow in tidal estuaries & coastal zones of tropical areas; muddy water = nutrient-rich.
25% of tropical coastline; provide food, fuel, materials, & med.; protect coastlines (absorb the force of storms); natural filters (absorb nutrients).
Pressures on mangroves: lost to rice paddles & shrimp farms; pop. growth in coastal areas inc.; Caribbean & S Pacific mangroves disappeared.
Overexploitation (Sabah = 40% of mangrove for wood ships); mangroves removed for urban expansion (rapid coastal development).
Integrated Coastal Zone Management (ICZM): developed due to pop. growth & mangrove destruction; sustainable use of mangroves.
1760: King José of Portugal, mangrove trees not cut for other uses; 1759: India, intensive management.
Restoration & Afforestation (plant mangrove trees); Managed Realignment (migrate inland); Flow Restoration (artificial flooding of wetland); Generic Protection (legislation to protect mangrove trees); Protected Area (1200 areas globally are protected, conservation/sustainability)
Sovereignty Right of Nations
Exclusive Economic Zone (EEZ): A coastal nation has sovereign rights over all economic resources of the sea, seabed, & soil
Extends up to 200 nautical miles from the coast; impact on the conservation of resources (can exploit, develop, & manage all resources).
90% of oil reserves & 98& of fishing regions under sea fall under a country’s EEZ
Ascension Island: the UK claimed ownership of 200 thousand km2 of Atlantic seabed surrounding Ascension Island.
Mountainous ocean floor up to 560 km from the island in S Atlantic = extensive mineral deposits (no near neighbours, no challenges).
Britain claims underwater territories around Rockall in N Atlantic (international interest in exploring seabed for scarce reserves).
Topic 4: Ocean Management Futures
Developing Abiotic Resources: natural resources found in the ocean (manganese, cobalt, copper, & nickel); difficult to gather (4 km of water)
1970s: industrial commodity prices higher & tech. Advanced; profitable to exploit minerals in ocean
2004: multiple countries were awarded licenses by the International Seabed Authority to explore mining possibilities on deep-ocean seabed
Nautilus Minerals (Canadian) = first deep-water mining company ; ore w/ copper & gold from Bismarck Sea (Papua New Guinea)
Hydrates: compounds of methane molecules trapped in water; found in permafrost (1960) & beneath ocean surface (1970)
Contain more energy than fossil fuel deposits; occur on fault lines; difficult to extract; methane traps more heat (global warming).
Oil: exploration = major activity in the Gulf of Mexico, South China, & North Sea; spills contaminated oceans; toxic effects on wildlife.
Threatens sea corals; hydrocarbons disorientate marine animals; shipping burns bunker oil - more CO2 & particulate matter.
2010: ban single-hulled ships; ban tributyltin (toxic chem. added to paint for ship hulls, kill algae & barnacles)
Case Study: Gulf of Mexico; 2010 = collapse of Deepwater Horizon oil rig; 4.9 M barrels of oil entered Gulf; 160 km of coastline affected
Attempt to plug the leak by pumping mud in a blowout preventer (unsuccessful, the force of oil upwards greater than mud)
Dispersants used to break up oil slick; order US gov. to limit use (prevent further damage to marine life in the Gulf of Mexico)
Topic 5: Environmental, Economic, & Geopolitical Consequences of Overfishing
World Fisheries: 2012 = 160 M tonnes of fish ($215 B); fish supply as food inc. since 1961 (inc. 3.2% per year); Asia = 67% of total consumption
China = 35% in 2010; Globally = feed 3 B ppl, 20% of animal protein; North-west Pacific & Western-central Pacific = largest catches
Fish Stocks: 2011 = global capture production is 93.7 M tonnes; 2012 = 86.6 M tonnes
Declining stocks: catch fewer predatory fish & more small fish further down the food chain; affect the marine ecosystem
70% of global stocks need management; code in the North Sea has declined 10% since 1970; boats from the EU fish in other oceans.
Illegal Fishing: 26 M tonnes ($ 23 B); Satellite Application Catapult = monitoring system, automatic identification system (AIS) from ships
Virtual watch room tracks vessels globally using AIS data; alert when the vessel enters prohibited waters & slows down to fishing speed
Strategies for European Fishing Industry: World Bank report = $50 B per year lost to poor management, inefficient, & overfishing globally
Fishing capacity & some vessels inc.; each boat has a greater capacity (tech.); investment in new tech. wasted (overcapacity)
Amount of fish caught stable since 2016; depleting of fish stocks (more effort to catch remaining fish)
Case Study: Grand Banks, Newfoundland; closed in 1992 to allow stocks to recover; fish numbers not yet recovered (still low)
Cod niche in ecosystem taken over by other species (shrimp & langoustines)
Aquaculture: raise fish commercially (food); fish hatchery releases juvenile fish into the wild (recreational fishing or supplement species)
1980 to 2010 = inc. by 8.8% per year; 2012 = 66 M tonnes ($140 B); vulnerable to disease & environmental conditions
China: 2012 = 40 M tonnes of food fish & 13.5 M tonnes of aquatic algae ; HICs = reduce aquaculture output (competition)
High tech. costs (use antibiotics to keep fish healthy & steroids to improve growth); breeding program cost; high output and efficiency
Farmed salmon = net loss of protein in global food supply; most production uses non-carnivorous fish species
Use other fish species to produce feed for salmon (deplete other fish species); disease spread from farmed salmon to wild stocks
Cause pollution (uneaten food, chemicals, waste); contaminate waters (organic debris & steroids)
Escape of fish affects wild fish gene pool (interbreed w/ wild pop. & reduce genetic diversity, introduce non-natural genetic variations)
Initiatives to Manage Oceanic Pollution: North Sea = 50% of litter from ships; 80% of litter is land-based; 250 000 kg of waste in North Sea
Marine litter causes economic damage (loss for coastal communities, tourism, shipping, & fishing); cost for EU to clean = €630 M per year
Radioactive Waste: 1958-1992 = Arctic Ocean, Soviet Union, 18 nuclear reactors (still contain fuel); nuclear power process & radioisotopes
Nuclear waste remains radioactive for decades; Fukushima Daiichi, Japan = carried across Northern Pacific towards Canada & USA
Plastic: 2006 = 18 000 plastic pieces per km2 of sea (most in central Pacific, 100 M tonnes suspended in jetstream); 90% carried from land
Takes decades to decompose or sink; affects wildlife (eaten by turtles); break up of plastic attracts toxins (conc. in tiny organisms)
Case Study: Great Pacific Garbage Patch (GPGP) - con. of marine pollution by ocean currents; slow-moving mass, N Pacific gyre ; 15 M km2
Currents = circular effect ; pulls debris from North America, Asia, & Hawaiian Island ; Midway Islands = coral reef, birds = plastic in system
Photodegradation of Plastic: split into smaller particles (still plastic) ; particles in GPGP = too small to see
Chinese Expansion in South China Sea: vital trade artery (30% of world trade passes) ; China threatening 70 years of naval supremacy in W Pacific.
2016: installed two launch batteries for surface-to-air missiles on Woody Island (Paracel archipelago) ; claimed right to self-defence facilities.
Paracels also claimed by Vietnam & Taiwan; China insists virtually all of the sea is theirs
Built over coral reefs in Spratly Islands (4 km2 for military use); artificial land on rocks & reefs, claimed by Philippines, Taiwan, & Vietnam
2030: South China Sea on trend to become a ‘Chinese Lake’; legal, diplomatic, & military approaches to moderate China’s behavior
Legal = Philippines brought UNCLOS (United Nations Convention of the Laws of the Sea) to show China’s historic claim
Diplomatically = China negotiates with ASEAN (Association of Southeast Asian Nations) members individually
Military = increase in defense spending in China; USA = only power capable of standing up against China
The USA: wants to turn two Pacific Islands into military training grounds (live fire exercise for 16 weeks per year); Tinian & Pagan (uninhabited)
Changes in the Arctic: sea ice disappearing; potential trade routes & access to oil and gas reserves
Case Study: Arctic ; Canada = year-round presence ; Denmark = prove detached part of Lomonosov Ridge = Greenland ; Russia = staked claim
2008: Canada, Denmark, Norway, Russia, & USA ; divide resources in Arctic Ocean (25% of undiscovered oil, 90 B barrels & natural gas)
2015: Arctic Frontiers conference; planktonic animals abundant (inc. fishing potential)
Environmental groups = ban military & mineral mining; 1982 UN Law of the Sea Convention = tangle of overlapping Arctic claims
El Niño: a reversal of the normal atmospheric circulation in the southern Pacific Ocean, beginning arm water and low pressure to the eastern Pacific, and cool water and high pressure to the western Pacific
Occurs once every 2-10 years and lasts 12-18 months
La Niña: intensification of normal atmospheric process
The cold current that flows from the east across the equatorial Pacific Ocean
Occurs when low pressure in the western Pacific becomes even lower
Hurricanes:
Hurricanes (Tropical Cyclones): low-pressure systems; high-intensity rainfall, strong winds, & heavy waves (flooding & mudslides).
Originate from moist, tropical seas; erratic path; winds spiral rapidly around the calm area (eye); pressure contrast = strong gale-force winds.
Move excess heat from low latitudes to higher latitudes; begin as small-scale tropical depressions (low pressure, warm air rises).
Sea = temp. above 27°C and a depth of 60 m; low-pressure area far from the equator (Coriolis force rotates rising air mass); unstable conditions.
Saffir-Simpson scale = assign hurricane to 1 of 5 categories of potential disaster; based on wind intensity; formed in Atlantic and Pacific
Case Study:
Typhoon Haiyan, Philippines
winds of 314 km/hr
10 000 ppl killed & buildings were destroyed
sea waters rise 6 m
World Food Programme = $2 million in aid
economic cost = $15 billion (many countries pledged aid)
vulnerable community (no savings)
Ocean Role and Acidification:
Ocean Acidification: freshwater = pH of 7 & surface seawater = 8.2 (dropped to 8.1) ; absorption of CO2 by oceans ; 0.1 difference = inc. of 30%
Absorbed 50% extra CO2 during the industrial age; anthropogenic causes (human actions); threatened species (fisheries & coral reefs).
30% of human-made carbon absorbed by oceans; reacts and turns into carbonic acid - reducing calcification of organisms (growth rate Dec. 14%).
Pacific coast = failure of commercial oyster; Great Barrier Reef = coral bleaching; Poles / high latitudes = shellfish (pteropod) reduction
Oceans as a Source and Store of Carbon Dioxide: largest CO2 sink (90% of carbon); carbon on ocean floor lifted (thermohaline circulation) = source.
Cold glacial phases = atmospheric CO2 decreased, stored in oceans ; Warm interglacials = CO2 released from oceans (inc. atmospheric CO2).
CO2 reservoirs = fossil fuels, atmosphere, & oceans ; carbon cycle (photosynthesis produce CO2 & released by volcanic activity, long timescale)
Features of Erosion: bays (hard rock = headlands, weak rock = eroded to bays) ; Bayhead beaches = constructive waves, deposit sand b/w headland
Faults erode into sea caves; arch = two sea caves meet; stack = roof of arch collapse (further erodes into stump); energy of wave refraction
Wave-cut (shore) platforms: intertidal, high-tide, or low-tide; high-energy; cliffs eroded to lower-angle cliffs; subaerial processes
Cliffs: depend on geo. Structure and subaerial & marine processes; low resistance rocks = easily eroded, can’t support overhang.
Features of Deposition: requires a large supply of material, longshore drift, irregular coastline, low-energy, & bioconstruction.
Storm waves = winter, Swell waves = summer; destructive waves = reduced beach angle; small sediment = reduced impact of swash & backwash.
Spit: the beach of sand linked at one end to land; indented coastlines or river mouths; thin attached end (proximal end) & larger end (distal end).
Curved, waves undergo refraction; longshore drift = moves sediment along the coast, and irregular coastline = refraction (waves bend).
Beaches & Sand Dunes: large dunes = mid-latitude, storm waves (sand supply, high onshore wind speed, low precipitation & humidity)
The tidal range exposes sand (eroding rivers); free dunes (no vegetation, desert), embedded dunes (vegetation trap sand, humid areas)
Case Study: The Palisadoes, Jamaica; largest deposited coastal system in the Caribbean (13 km, 4000 yrs old)
Longshore drift = east to west provides sediments; located at a sharp bend in coastline (sediment carried westwards); extends the length of the spit
Spit grew longer and linked with small islands (cays); forming a tombolo; an area vulnerable to natural disasters (tropical storms & hurricanes)
Advancing and Retreating Coastlines: isostatic change = localized change in level of land relative to sea level; rise = tectonic uplift (remove ice)
Global warming (enhanced greenhouse effect) raises sea levels, impacts low-lying communities
Retreating = rate of erosion exceeds the rate of deposition (submerged coasts); Advancing = rapid deposition (emerging coasts).
Coastal Processes, Wind, & Vegetation in Sand Dune Development:
Sand moved by wind (up to 1 mm); grains above 1 mm = saltation (move by turbulence); irregular = inc. wind speed, more sediment moved
Shore = soil contains few nutrients, mostly sand, “yellow dunes”; vegetation needed for stable dune (dec. wind speed, deposition can keep up)
Reduce wind speed = less evapotranspiration loss (moist soil, decaying marram add nutrients to soil - more acidic)
Slack (low points b/w dunes) = moist conditions; marsh vegetation; rear of dune system = “grey dunes” - humus in soil
Many shells = calcium, form grasslands; calcium leached from old dunes = acid dunes (outwash of sand and gravel)
cks
Cost-Benefit Analysis of Coastal Defence: costs of building & maintenance, reduced beach access; protection buildings & rising land price.
New York: Superstorm Sandy in 2012; 14 ft storm surge; defences = 12 ft; $20 B in damages versus $19 B for new defecses
Fukushima-Daiichi tsunami: 2011; surges over 11 m; overt topped 10 m high sea walls
Case Study: Palisadoes spit; storm surges & coastal flooding led to erosion of tourism & coastal protection) = $375 B
pansion (rapid coastal development).
Ital nation has sovereign rights over all economic resources of the sea, seabed, & so Bismarck Sea (Papua New Guinea)
Hydrates: compounds of methane molecules trapped in water; found in permafrost (1960) & beneath ocean surface (1970)
Contain more energy than fossil fuel deposits; occur on fault lines; difficult to extract; methane traps more heat (global warming).
Oil: exploration = major activity in the Gulf of Mexico, South China, & North Sea; spills contaminated oceans; toxic effects on wildlife.
Threatens sea corals; hydrocarbons disorientate marine animals; shipping burns bunker oil - more CO2 & particulate matter.
2010: ban single-hulled ships; ban tributyltin (toxic chem. added to paint for ship hulls, kill algae & barnacles)
Case Study: Gulf of Mexico; 2010 = collapse of Deepwater Horizon oil rig; 4.9 M barrels of oil entered Gulf; 160 km of coastline affected
Attempt to plug the leak by pumping mud in a blowout preventer (unsuccessful, the force of oil upwards greater than mud)
Dispersants used to break up oil slick; order US gov. to limit use (prevent further damage to marine life in the Gulf of Mexico)
hing speed
Extreme Environments
Characteristics of Extreme Environments
Extreme Environment: relatively inaccessible areas that tend to be viewed as inhospitable to human habitation, though they do provide opportunities for settlement and economic activity
Clod & high altitude environments
Polar, glacial, periglacial & high mountains in nontropical areas
Hot, arid environments
Hot deserts and semi-arid areas
Distribution of Extreme Environments
Cold and high altitude environments → uneven distribution
Northern hemisphere → periglacial belt
Located towards the north and south poles where insolation is low
Desert and Semi-Arid environment
Covers ⅓ of the earth's surface
Generally located around the tropics
Due to permanent high-pressure systems that limit rain formation
Reason for Distribution
Both environments
The angle of incidence: the angle at which light strikes the surface of the Earth
The greater the latitude, the less sunlight the area receives
Sun’s rays strike the surface at a lower angle near the polar
Atmospheric circulation
Hot air near the equations rises and moves toward the poles
At around 30 degrees latitude → air pushed downwards due to the Ferrel Cell’s Wind Circulation
Ferrel Cell’s Wind Circulation: Driven by temperature differences, cool polar air masses, and warm subtropical air masses converge, pushing each other upwards along their meeting line around 60 and 70 degrees north and south.
Creates high pressure in the tropics
Cold air at poles is very dense → dense → creates high pressure + low-temperature environments
Reflection and Scattering
Reflection: most of the heat that reaches the surface in polar areas is reflected into space due to the shiny surfaces of ice caps and snow
Scattering: there is a greater thickness of atmosphere near the polar than at the equator that the sun’s ray must penetrate → more energy is reflected and scattered
Due to location sun rays enter the atmosphere in polar areas at an oblique angle → gasses absorb more heat and light, so less reaches the surface
Length of Daylight Hours
On equator → length of days is the same throughout the year (day = 12 hours, night = 12 hours)
Further from equation → more variation
Summer → more daylight
Winter → night lasts longer
Cold Environments
Altitude
The higher in the troposphere (first layer of the atmosphere), the lower the temperature
Lapse Rate: the rate at which temperature drops
Caused by adiabatic cooling
Adiabatic Cooling: the cooling of an air parcel as it rises adiabatically in the atmosphere
Arid Environments
Offshore Currents
Many deserts are on the west coast where the water is cold
Winds blow parallel to the coasting & push surface water towards the sea
Cold water draws upwards (upwelling) to replace surface water
The air’s capacity to hold moisture is diminished
Rainshadow Effect
Rising air at the slope of the mountain towards the wind cools and loses moisture
Descending air on the other side of the mountains warms up → decreasing its relative humidity → causing it to be dry
Characteristics of Extreme Environments
Cold & High Altitude Environments
Climate
Low temperatures all year around
Mountain environments
a large amount of rainfall → due to relief rain
Low rainfall → rain shadow area
High diurnal temperature ranges → Underlying rock weakens due to extreme freezing
Can easily lead to avalanches
Relief
Steep and rocky terrain which is mostly inaccessible
Young mountains have steep gradients and weak rock structures
The area is a frequent risk for rockfall and mass movement
Slope Aspect: the direction that a slope faces
Northern hemisphere (most of highest mountains) → slopes face south
Get more sunshine for longer periods of time
Causes difference in vegetarian and land uses than northern aspect
Altitude and Biosphere
Mountain areas have vertical series of bands of vegetation
Altitude affects temperature
As animals need vegetation for food → distribution is also along the altitude zones parallel to vegetarian
The number of species declines with increasing altitude
Tectonic hazard
Tectonics uplifts → mountain ranges
Still ongoing → creates constant instability
Areas around are affected by earthquakes
Wealthy countries → build earthquake-proof structures
Desert and Arid Environments
Climate
Moist defects
Generally low amount of rainfall
Rainfall Variability
Very high for arid regions
Varies from year to year
Diurnal Fluctuations
Arid regions generally have a large diurnal temperature range
Deserts near the sea have a moderating effect
Seasonal Fluctuations
Equatorial deserts: little season changes in temperatures
Subtropical deserts & mid-latitude deserts: great variation between winter and summer temperatures, especially in high altitudes
Wind
Arid regions are typically windy
Sparse vegetation
More air movements
Lack of frictional drag from trees
Connection can also cause heavy winds
Sun heats the ground and dry air above, which expands and rises, with cooler air coming in to replace
Wind removes moist air → increases evapotranspiration
Flash floods
Normally deserts may have irregular flash floods
Challenges for Human Habitation
Cold and High-Altitude Environments
Cold Environment
Typically have unstable terrain
Waterlogged solid → deteriorates vegetation growth and causes solifluction → unpredictable terrain change
Solifluction: seasonal freeze-thaw action upon waterlogging topsoils which induces downslope movement
Difficult to source liquid water & insulated pipes to carry them
Short growing season → outsources food
Roads ice frequently
Frost heave can cause damage
Ice Heaves: sheets of ice that push against each other or the shoreline. They form when ice sheets expand due to rapid temperature fluctuations. Thermal expansion of the ice occurs when a rapid increase follows a period of very cold weather in temperature
High Altitude Environment
Have great diurnal temperature variations
Think and weak soil → no fertility for agriculture & harsh winds
Generally low rainfall
Steep topography → accommodating infrastructure and communication is difficult to build and maintain
Altitude increases → decrease in air density, water vapor → dehydration, carbon dioxide, and boiling point of water → difficult to cook
Frequent avalanches → destroy settlements
Desert and Arid Environments
Lack of water and precipitation
No freshwater → impossible to farm and maintain livestock
Use chemical weathering to achieve finer soil
Great diurnal temperature variations
extremely high during the day and extremely cold during the night
Extreme temperatures limit vegetation growth
Changing Distributions of Extreme Environments
Glacial advancements and retreats
Glacier: Slow-moving mass of ice formed by accumulation and compaction of snow on mountains or near poles
Although solid, behaves like thick liquid and flows at an extremely slow rate under gravity
Glacial system → balance of inputs (accumulation of snow, avalanches, debris, heat), storage (ice, meltwater, moraine), and outputs (losses due to ablation: melting, sublimation, evaporation)
Ablation: all methods by which the glacier can lose mass. In this zone, there is a net loss in mass when outputs are greater than inputs
If accumulation > ablation → glacier avances
If accumulation < ablation → glacier retreats
If accumulation = ablation → glacier is steady
Glacier will have a positive regime when supply is greater than loss → thicken and advance
Glacier will have a negative regime when wasting is greater than supply → thin out and retreat
Natural Desertification
Desertification: the process by which deserts expand into semi-arid areas or become more intense
Variations in rainfall/drought/increased aridity can cause deserts to expand or retrace
Physical Processes and Landscapes
Glacial Processes and Landscapes
Glacial erosion
Plucking
Occur at the base of the glacier
As ice moves, meltwater seeps into joints and freezes to the rock → ripped out when the glacier moves
Can be used for abrasion
Abrasion
Debris carried by the glacier scrapes and scratches the rock
Finer material will smooth out the rock → producing gently sloping landforms
Factors affecting glacial erosion
Relative hardness of particles and bedrock
Most effects abrasion: har particles + soft bedrock
Ice thickness
Greater the thickness → greater the vertical pressure → more effective abrasion
Basal water pressure
Basal water pressure may lift the glazier above the level of particles that the base, reducing the among of the brain
Sliding of basal ice
Faster the rate of basal slides → greater the rate of abrasion
Movement of debris towards the glacier base
If particles at the glacier base are not renewed → become polished → less abrasion
Debris particle size and shape
Large and angular debris abrade much more effectively than small and round debris
Landforms produced by glacial erosion
Cirque: an oval-shaped depression in the side with a steep back wall and a rock lip
Arete: narrow, knifed-edged ridge
Pyramidal peak: pointed peak with radiating aretes
Glacial trough: steep-sided u-shaped valley
Hanging valley: tributary glacier left high above the main valley
Truncated sur: steep cliff-like valley sides
Rock steps: stepped long profile in a glacial trough
Ribbon Lake: long narrow lack in glacial trough
Cirque lake: small, deep, circular lake
Roche Moutonné: ice-smoothed rocks with steeper side facing down-valley
Striations: rocks scaled with parallel scratches
Periglacial Processes and Landscapes
Freeze-thaw: the process by which the freezing of water puts pressure on rocks (especially jointed rocks). Only occurs when the temperature fluctuates above and below freezing points are there are cycle of strain and release
Mass Movement
Frost Heave: the expansion of fine-grained soils such as silts and clays to form small domes. Results from the direct formation of ice.
The thermal conductivity of stones is greater than spil so they are underneath the stone become colder → ice crystals form
The crystals force the stones above them to rise
Solifluction: Common when surface sediments are poorly drained and saturated with water. Occurs when tyres are above zero and free liquid water is available in the action later
In winter, water freezes in the soil, causing expansion and secretion of individual soil particles
In spring, the ice metals and water flows downhill
Water cannot filtrate the soil due to permafrost → flows over and caries the segregated soil particles and deposits them further down
Frost creep: type of solifluction that occurs because of frost heaving and thawing
Starts with the freezing of the surface ground, angling particles at right angles. As ice thaws in the warm season, contracting surface drops particles in elevation due to gravity → particles move slightly downslope
Rockfalls: occur when fragments of rock break away from a cliff face from freeze-thaw weathering
Periglacial Landscapes Features
Permafrost: permanently frozen subsurface
To be classified as permafrost must be frozen for at least 2 years
Commonly occurs in periglacial environments
Types of permafrost
Continuous
Discontinuous
Sporadic
Thermokarst: irregular, hummocky terrain with marshy or lake-filled hollows created by the disruption of permafrost's thermal equilibrium
Pingos: dome-shaped isolated killed with interrupt flat tundra plains. Form as a result of movement and freezing of water under pressure
Open-system pingos: forms when the source of water is a distance elevate the source
Closed-system pingos: forms when the supply of water is local and permafrost expands
Often form on site of small lakes where water is trapped by freezing from above
Physical Processes in Hot Arid Environments
Mechanical weathering
Salt crystallization: a form of weathering which causes the decomposition of rock by the solution of salt, causing chemical and physical changes in the rock
Disintegration: a form of weathering where the grains of rock become loose and fall out, leaving a pitted surface
Occurs in deserts with lar diurnal temperature ranges
Erosion
Water
Exogenous rivers: rivers that have their source in wetter environments and then flow through a desert
Endorheic Rivers: rivers that drain into an inland lake or sea
Ephemeral rivers: Rivers that flow seasonally or after a storm and tend to have high discharges and sediment levels
Wind
The movement of sediment is crashed by drag and lift forces, also known as suspension, but are reduced by particle size and friction
Deflation: Progressive removal of fine material by the wind leaving behind larger materials
Abrasion: sandblasting action acted by materials as they are moved by alteration
Saltation bouncing of sand particles by wind forces
The process smooths away rock close to the ground
Landscape features in hot arid environments
Formed by deposition
Dunes: develops when sans Grania, moved by saltation and surface creep, are deposited
Form around large rocks, which hold the main part of the dune in place
Formed by wind erosion
Yardangs: extensive ridges of rock. They are separated by troughs, and have an alignment similar to the prevailing winds.
The strata are vertical
Zeugens: tabular masses of resistant rock separated by trenches where the wind cuts vertically through the cap into the underlying soft rock
The strata are horizontal
Rock petals: formed by exposed isolated rocks in the series when a more resistant layer of sedimentary rocks sits above a softer layer
The lower softer rock erodes faster than the higher, more resistance-rich
Oases: fertile spots in the desert where water is found. Formed where natural depressions are deep enough to cut into water table
This leads to semi-permanent water is available near the surface
Formed by water erosion
Wadis: dry river channels that are generally steep-sided and flat-bottomed. May have formed during flash floods or during wetter pluvial periods in the Ice Age when the runoff collected from sheet flood becomes concentrated into deep ravines
Measea: Plateau-like featured with steep-sides
As the mesa is reduced in size by cliff retreats, it rains its flat top and altitude
Buttles: a smaller version of mesas, representing the final stage of erosion before the resistance rock is finally eroded
Managing the Future of the Environment
Agriculture in Arid Areas
Benefits: The environment offers an abundance of heat and sunlight, favoring a lengthy growing season. If water is available, farming can be an opportunity. Opportunities include:
Nomadism
Settled farming with groundwater
Irrigation next to rivers and oasses
Increased use of drought-tolerant species
Challenges and possible solutions: The area is dominated by the lack of fresh water, too much sunlight and heat, low rainfall seasons, alien waters, strong dry winds, poor soil structure, overgrazing, and poor transport. All arid and semi-arid have negative water balance (outputs from evapotranspiration and stores of water exceed this input from precipitation
Soil is arid due to low rainfall and high evapotranspiration
Soil is infertile due to:
Low organic content
Generally thin with few minerals
Lack of clay
Soluble salts in soil which can be toxic to plants
Irrigation access
Not all areas have access to irrigation
To the areas that do, problems include salinization, depletion of groundwater, pollution, and less access to water elsewhere
Salinisation Risk
May occur in areas where the water table is close to the surface & annual precipitation is less than 250 mm
In poor drainage locations (ex. Valleys and basins), surface water evaporates and leaves behind large amounts of salts
Saline soils adversely affect the growth of more crops
Reduces rate of water uptake by roots
Sustainability
Agriculture in arid and semi-arid environments can be made more sustainable by:
Reducing her size and pressure on the amount of limited vegetation
Use solar panels to produce energy
Plant vegetation
Use more efficient types of irrigation
Building check dams to collect water
Using more salt-tolerant plants
Mineral extraction
In extreme environments: opens up opportunities for poorly developed regions, employ opportunities, and can generate significant income from exports
In cold environments: resource development can improve, but can put the environment under pressure and create conflict
Due to inaccessible, there is a high cost of attracting workers
Fragility Of periglacial areas
The limited ecosystem is highly susceptible to interference
Low temperature limits decomposition, which can lead to pollution (especially oil)
Frost heave
Can lift piles for oil pipelines and structure out of the ground → need to be embedded deeper which is expensive
Resource nationalism
Governments tend to assert control of natural resources in their territory and conflict with the interest of multinational corporations
In arid environments: huge potential for development and generate large earnings for countries that develop them
Due to inaccessibility, there is a high cost of attracting workers and protecting people from extreme heat and aridity
Politics
Risk of intruding on rights of Indigenous people
Environmental impact
The movement of people and vehicles can introduce exotic species
Mines can be a major source of dust pollution linked to respiratory disease
Open-pit mining can expose dangerous chemicals and contaminated groundwater
Tourism in Extreme Environments
Cold Environments
Popular destinations due to scenery, rare species, pristine landscapes
Mountain environments have a low carrying capacity and are easily damaged by human impact because of this erodible soil and vegetation
Arid Environments
tourism opportunities may be linked to scenery, wildlife, indigenous culture and outdoor pursuits.
create jobs, provide income for workers,
Challenges include extremes of temperature, accessibility, water shortages and a lack of resources to sustain tourism.
The impacts on the natural environment include mass movement, erosion, land degradation, hazards, aesthetic changes, water shortages, waste, introduction of exotic species and habitat removal.
Future of Extreme Environments
Desertification
Desertification: Land degradation in humid and semi-arid areas (not including non-desert (arid) areas)
Involves the loss of biological and economic productivity and it occurs where climatic variability (especially rainfall) coincides with unsustainable human activities.
Causes
Desertification can be a natural process intensified by human activities. All areas affected by desertification are marginal and have highly variable rainfall, except rainforests desertified by inappropriate farming techniques.
Natural causes
Temporary drought periods of high magnitude and long-term climate change towards aridity.
Overgrazing
Vegetation is lost through grazing and trampling by large numbers of livestock.
Overgrazed lands become more vulnerable to erosion as compaction of the soils reduces infiltration (increasing surface runoff) and trampling increases wind erosion.
Fencing leads to severe localized overgrazing while boreholes and wells cover the water table, leading to soil salinization.
Overcultivation
This leads to diminishing returns (yield decreases every season) and so to maintain the return on agricultural investment, the area of growth must be expanded.
Reducing fallow periods and introducing irrigation help to maintain output, but contribute to further soil degradation and erosion by lowering soil fertility and promoting salinisation.
Deforestation
Occurs where land has been cleared to extend the area of cultivation and in the surrounds of urban areas for firewood.
The loss of vegetation cover increases rainsplash erosion and the absence of root systems allows for easy soil removal by wind and water.
Climate change
Soils exposed to degradation as a result of poor land management could become infertile as a result of climate change.
Climate change may exacerbate desertification through alteration of spatial and temporal patterns in temperature, rainfall, solar radiation and winds.
Access to Resources In Extreme Environments
Arctic region
As ice caps are melting, a military race between the US and Russia competing for its extremely valuable resources
The region is opening up two major shipping lanes, and oil and gas reserves are worth trillions of dollars.
If the Arctic region continues to melt and open up vital shipping lanes, there must be international cooperation to provide security and rescue elements for commercial shipping.
Oil conflicts in the Middle East
Conflicts over oil are the result of long-standing historical disputes, which have developed into the desire to control valuable oil and natural gas assets.
The economic world has become energy-centric, and access to energy resources provides strength and power for some countries, whereas lack of resources leads to vulnerability for other countries.
Countries with surplus energy reserves, and the ability to export energy, often have a disproportionate influence on the world stage.
ISIS: A Sunni extremist group that controls large parts of western Syria and northern Iraq. ISIS controls key oil-producing areas of Syria and oil-refining facilities in Iraq. This, in part, allows it to pay for its military. Such conflicts make it difficult for countries that depend on Middle Eastern oil.
Sustainable development: New technology and sustainable developments in extreme environments
Sustainable development: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs. They should fulfil needs, in particular the essential needs of the world's poor, but are restricted by limitations imposed by the state of technology and social organization on the environment's ability to meet these present and future needs.
Solar power
A completely renewable resource which has non-direct pollution during electricity generation and requires little maintenance.
However, there are high initial costs for solar plants and it is limited in that power cannot be harnessed at night or in countries with low annual hours of sunlight
Desalination
The removal of salts and minerals from seawater and soil.
Due to high energy input, the costs of desalinating seawater are generally higher than the alternatives, but alternatives are only sometimes available and depletion of reserves is a problem in certain locations.
The main criticism regarding desalination and the use of reverse-osmosis technology is that it costs too much.
Aquaponics
An integrated form of farming that enables farmers to increase yields by growing plants and farming fish in the same closed freshwater system.
Mimics natural processes and enables waste to be efficiently reused.
Climate change and EEs
The impacts and management of global climate change in extreme environments, including adaptation by local populations
Climate change impacts on arid environments:
Food security
As temperatures rise, evaporation levels will increase and reduce precipitation effectiveness.
Environmental hazards such as floods and droughts will become more common in arid areas like the Sahel, disrupting agricultural systems
reduce food production and availability and increase prices, food insecurity and hunger.
Poverty will exacerbate the impacts of climate change in these areas.
Local adaptation strategies by Senegal:
Improving soil fertility by the careful use of fertilizers
Improving the efficiency of irrigation systems and pest control
Adopting water and soil conservation techniques using baguettes (stone rows) to reduce run-off on slopes
Developing the Great Green Wall of the Sahara and the Sahel Initiative (GGWSSI), that is, a massive line of trees across the southern Sahara and Sahel to combat the combined effect of resource degradation (deforestation and soil erosion) and drought/desertification
Coping strategies for water shortages
Adaptations to water shortages include:
Increased mobility (the traditional way)
Management of size and composition of herds
Exchange of livestock and livestock products
Increased use of drought-tolerant species
Utilization of wild species and tree crops
Windbreaks to reduce wind erosion of bare soil
Irrigating with silt-laden river water to restore soil
Dune stabilization using straw bales and xerophytic plants
Land enclosure to reduce wind erosion
Climate change impacts on cold environments
Any increase in temperature is likely to have a greater impact in areas where the mean annual temperature is only a little below the freezing point.
risk of degradation and the development of thermokarst (subsidence).
Benefits
The warming climate has made minerals that were once locked in ice accessible.
Farming may become more productive as net primary productivity increases and the length of the growing season increases.
Consequences
Many settlements are located at river mouths, river confluences or islands.
Melting permafrost, coastal erosion, increased flooding and a rise in sea level due to climate change will take a toll on buildings, ports, bridges and roads.
This will increase the number of climate refugees as well as death tolls from unpredictable sea ice.
life in cold extreme environments will become more expensive (e.g. snowmobiles must take longer routes, and buildings are weakened by melting permafrost).
People relying on fishing will either have to go further to catch or alter to take into account changes in species composition.
Hazards and Disasters-Risk Assessment and Response
1. What determines the severity of a hazard?
Duration:
The length of time that a hazard lasts.
As a general rule the longer the hazard the more severe it is likely to be.
Example: an earthquake that lasts 1 minute is likely more severe than one that lasts two seconds and a drought that lasts ten years is likely more severe than one that lasts three months.
Magnitude:
This is the strength of a hazard.
Most hazards are measured on a scale
Example: the Richter scale or the volcanic explosivity index (VEI).
Generally speaking, the stronger the hazard the more severe the hazard is.
Predictability:
Some hazards are easier to predict than others.
Example, volcanoes normally give warning signs before they erupt and tropical storms can be tracked from development to landfall.
However, others like earthquakes are much harder to predict.
Generally speaking, hazards that hit with no warning will be more serious.
Regularity:
If hazards happen often and in quick succession
Example: an earthquake followed by multiple aftershocks then the severity is likely to be greater.
During hurricane seasons, countries can be hit by repeated storms each causing greater damage because it has not been possible to recover from previous damage.
Frequency:
The return interval of hazards of certain sizes.
Example, earthquakes with a magnitude of over 8.0 happen on average once
If the hazard is a less frequent strong event, then it is going to have a bigger impact.
Speed of onset:
If the peak of the hazard arrives first or arrives quickly
Example: an earthquake, then the affects are likely to be worse than one that arrives slowly
Example: a drought.
Spatial concentration:
Where hazards are located or centred.
Example: earthquakes tend to be focused along plate boundaries, whereas tropical storms tend to be located in coastal areas in the tropics.
Hazards that are located in known areas can be better prepared for and managed better.
Areal extent:
If a hazard covers a large area
Example: a drought covering the whole of East Africa, then the severity of the hazard is likely to be more severe, than a flood hitting just one village.
The number of hazards:
If multiple hazards hit a location the effects can be more severe.
Example: hazard hotspots like Indonesia can be hit by earthquakes, volcanoes, landslides and flooding all simultaneously.
2. Predicting Earthquakes
Scientists can attempt to predict by looking at:
Microearthquakes
Changes in rock stress
Ground subsidence, uplift or tilt
Changes in magnetic field and electrical resistivity of rocks
Animal behavior
Seismic history
3. Factors Affecting the Impact of Earthquakes:
Depth: If the hypocentre of an earthquake is close to the surface then it is more likely to cause greater damage than a deep earthquake.
Duration: A longer earthquake is likely to cause greater damage than an earthquake that lasts only a few seconds.
Magnitude: A stronger earthquake is going to have a greater impact than a weaker one.
Time of Day: Time of day can be important. If people are sleeping and get trapped in their beds more people can be killed. In Japan, an earthquake that struck while people were cooking their evening dinner caused widespread secondary hazards (fire) that caused more deaths.
Epicentre Location: If the epicentre of an earthquake is an uninhabited region it is going to have a lesser effect than one under a densely populated city.
Geology: If an earthquake occurs in solid bedrock it is likely to cause less damage than one centred below an alluvial floodplain which may lead to liquefaction.
Economic Development (buildings, planning, preparedness): Generally more developed countries have better zonal planning, building codes and preparedness meaning the effects of the earthquake are less.
4. Hurricanes
Hurricanes are normally measured by using the Saffir-Simpson Hurricane Scale developed by the National Oceanic and Atmospheric Administration.
Hurricanes are measured on a scale of 1-5 depending on their wind speed and storm surge.
Category five storms only sometimes cause the most damage.
The amount of damage caused by hurricanes can depend on several factors including:
Where landfall is (populated or non-populated area)
The development of the country
The warning given to residents and the preparedness of residents.
The existing conditions (saturated ground or not)
5. Drought
Studies conducted over the past century have shown that meteorological drought is never the result of a single cause.
It is the result of many causes.
Scientists don’t know how to predict drought a month or more in advance for most locations.
Predicting drought depends on the ability to forecast two fundamental meteorological surface parameters, precipitation and temperature.
From the historical record, we know that climate is inherently variable.
We also know that anomalies of precipitation and temperature may last from several months to several decades.
How long they last depends on air–sea interactions, soil moisture and land surface processes, topography, internal dynamics, and the accumulated influence of dynamically unstable synoptic weather systems at the global scale.
Meteorologists have made significant advances in understanding the climate system.
It may now be possible to predict certain climatic conditions associated with ENSO (El Nino) events more than a year in advance.
For those regions whose climate is greatly influenced by ENSO events meteorological forecasts can reduce risks in those economic sectors (mainly agriculture) most sensitive to climate variability and, particularly, extreme events such as drought.
Droughts endanger lives and livelihoods through thirst, hunger (due to crops dying from lack of water) and the spread of disease.
Millions of people died in the 20th century due to severe drought and famines.
One of the worst hit areas was the Sahel region of Africa, which covers parts of Eritrea, Ethiopia and the Sudan.
Droughts and famines can have other geographical impacts.
If drought forces people to migrate to a new home it could put pressure on resources in neighbouring countries.
Droughts can have a severe impact on MEDCs as well as LEDCs.
Droughts have caused deaths in Europe in recent years - especially among the elderly.
In the UK in the summer of 2006, there were hose-pipe bans and campaigns to make people save water.
6. What factors influence our risk perception?
Is the risk voluntary? Professional soldiers for example will perceive the risk of being shot differently from a civilian.
Time scale: people perceive immediate impacts of a hazard as more severe and 'real' than long-term ones. In an earthquake for example the risk of a building falling on you is more feared than the long-term risk to your health.
Psychological perception: certain hazards create a very intense fear response in humans for example the fear of fire and any hazard that might cause this will be perceived as worse than an avalanche.
Understanding/Knowledge: We fear what we do not know much about or we fear it less due to a limited understanding of the true risk.
Media: Certain hazards are widely publicised and covered in the international media. This can colour our perception of risk.
For a disaster to be entered into the database of the UN's ISDR (International Strategy for Disaster Reduction), at least one of the following criteria must be met:
A report of 10 or more people killed
A report of 100 people affected
A declaration of a state of emergency by the relevant government
A request by the national government for international assistance
7. Methods available to dealing with hazards:
Preparation:
Governments might consider how they can educate and prepare their populations for a disaster so that they know what to do in a hazardous event.
Also, governments can put into place laws and building codes to govern what can be built and to what standard, so that hazard impacts from hurricanes, earthquakes etc can be reduced.
Prediction:
This is the mechanism by which we try to forecast when and where a hazard will occur.
There are a huge range of prediction methods now for a huge range of hazards, think about the Avalanche risk charts you may have seen whilst skiing.
We can use satellites, river flow meters, sulphur dioxide meters, tilt meters etc to predict different hazards.
We are better at predicting some hazards such as flooding, than we are others, such as earthquakes, because some of the warning signs are clearer and because of the amount of response time to each hazard.
Prevention:
These are the methods that we can put into place as human beings to either prevent the hazard entirely or prevent some of the negative impacts of a hazard.
Some hazards such as forest fires can be prevented, by using fire breaks and prescribed (deliberate fires) major forest fires can be stopped.
Other hazards cannot be prevented, such as Hurricanes.
However, we can prevent some of the flooding during hurricanes by having correct drainage systems and coastal defences.
8. Reducing Vulnerability - Preparation
Aid:
Aid can be used as an adjustment before potential hazards strike or after hazards strike.
Aid before hazards strike will take the form of development aid and may include:
The building of wells to reduce drought and disease
The improvement of irrigation and the introduction of GM crops to reduce famine
The building of dams to reduce the risk of flooding and droughts
The building of roads and mobile networks to improve transport and communication throughout a country
The building of schools to improve education about hazards
The building of hospitals to reduce hazards like disease and treat people injured in hazards
Aid given after a hazard or during a hazard is more emergency aid. Emergency aid may include:
The sending of rescue teams to search for victims
The provision of medicine or doctors to help injured
The provision of food and clean water
The provision of tents and blankets, etc.
Aid may also be given later to help rebuild after a disaster
Example: rebuilding homes, roads, schools, hospitals and electricity supply.
Insurance:
Insurance is the act of insuring (protecting) property, people, businesses, etc. against the risk of something happening.
Example: a person dying or being injured, or property being flooded or burnt down
To insure something it is necessary to pay a premium appropriate to the likelihood of something happening
Example: an 80-year-old person is likely to die fairly soon, so any premium will be high, but the likelihood of a 25-year-old dying shortly is much less so the insurance premium will be much less
Normally insurance policies are taken out with private companies, but if the risk of insuring is too high, then private companies may refuse insurance.
In these circumstances, governments will sometimes offer insurance.
Hazard Mapping (Land use planning or zoning)
Hazard maps are created by calculating the vulnerability of different areas to natural hazards.
Hazard maps are often made to calculate populations’ vulnerability to hazards like earthquakes, hurricanes, volcanoes and floods.
Once potential hazards are known then appropriate adjustments can be taken.
Adjustments may include:
Creating zones where building is not permitted because it is too dangerous
Creating zones where only low-value uses are permitted
Example: farming
Protecting areas that are vulnerable to hazards with the use of defences
Evacuating vulnerable areas (and possibly allowing managed retreat in coastal areas)
Rebuilding vulnerable areas to new building standards
When creating a hazard map several variables will be considered.
Example: scientists creating an earthquake hazard map will look at the following:
Proximity to plate boundary or known fault
Seismic history (frequency and magnitude)
Geology (bedrock is much more stable than alluvial deposits which are vulnerable to liquefaction)
Gradient (flatter ground is generally more stable than steep land)
Possible secondary hazards (proximity to the coast for things like tsunamis, but also hills for landslides (forested/deforested))
9. Responses to a Hazard:
Short-term response:
A response in the days and weeks immediately after a disaster.
Short-term responses mainly involve search and rescue and helping the injured.
Mid-term response:
Responses in the weeks and months following a disaster.
Mid-term responses involve re-opening transport links and getting electricity and water supplies operational again.
It might also involve establishing longer-term refugee camps where there has been large-scale destruction.
Long-term response:
Responses that go on for months and years after a disaster.
It involves rebuilding destroyed houses, schools, hospitals, etc.
It also involves kick-starting the local economy.
Leisure, Sport, and Tourism
1. Changing leisure patterns
Reasons for the increase in leisure time:
Increase in disposable income
refers to the income that is available to a person after tax
In most countries, disposable income has increased
allows people to save a significant percentage of their income for leisure or tourism
in some organizations, 10% of their income is saved and given to them at the end of the year for them to embark on tourism
Increase in advertisement
made it possible for people to know where they can visit for tourism
CNN advertises Malaysia, Azerbaijan, Turkey etc
Inflight advertisements showing places you can visit upon arrival at your destination
increase people’s chances of visiting tourist centres in the country of destination.
Transportation improvement
Improved air, sea and land transport has made it easier and possible to reach many tourist destinations
the world’s fastest aircraft, the Concorde, was twice faster than the speed of sound
high-speed trains that can travel about 300km per hour
shortened the distance between places, thus allowing people to embark on journeys at a much faster rate
Large cruise ships also promote packaged tours to places such as Venice in Italy or other Caribbean islands
contributing to people’s chances of engaging in tourism
Cheaper cost of transportation
Cheaper airfares and cheaper costs of travel by sea have also contributed to reducing the cost of travel
the large passenger plane, Airbus A320 can carry over 400 passengers at a time
many passengers would mean lower airfare per passenger
More leisure time for most workers
teachers have 13 weeks of holidays so they can decide to go anywhere they want
Reduction in the number of working days and hours for some workers in government institutions in some countries
Paid leaves
Early retirement
Development in technology
People spend less time on house chores, hence more time for leisure
Categorization of tourism and sporting activities
Sport:
Group 1- Athletics and Rugby (Archery, American football, Lacrosse, Gymnastics)
Group 2- Dancing and Yoga (aerobics, Pilates)
Group 3- Outdoor sports (fishing, cycling)
Group 4- Swimming, Cycling and gym
Group 5- Racquet sports and running. (Badminton)
Group 6- Bowing
Group 7- Cricket, football, pub sports
Tourism:
Primary tourist/recreational resources – the pre‑existing attractions for tourism or recreation (that is, those not built specifically for the purpose), including climate, scenery, wildlife, indigenous people, cultural and heritage sites
Secondary tourist/recreational resources, which include accommodation, catering, entertainment and shopping.
Ecotourism—tourism focusing on the natural environment and local communities
Heritage tourism—tourism based on a historic legacy (landscape feature, historic building or event) as its major attraction
Sustainable tourism—tourism that conserves primary tourist resources and supports the livelihoods and culture of local people
Mass tourism
Medical tourism
Adventure tourism
Niche tourism
Sex tourism
2. Tourism and sport at the local and national scale
Factors that determine whether the area is a hotspot include:
Climate:
If the area has extreme temperatures, it may not serve as a hotspot, unless there is a special event which requires extremely high temperatures, such as the annual desert race that takes place in the Sahara.
If the area is too cold, then it could serve as a skiing hotspot ( such as in the Alps).
The culture of an area:
If the people have some type of religion (Mecca or Jerusalem), cuisine, clothing (Kente or Bonwire), architecture or education (Oxford, Cambridge) then people would go there to view these things.
Example: Mecca is a hotspot for Islamic pilgrims who visit the Holy Site as a form of religious worship. Jerusalem and the Holy Sites also serve as a hotspot for Christian pilgrimage.
Natural Landscape:
If it is low-lying, it would be adequate for football, rugby, golf etc.
If it is mountainous and cold, it would be adequate for skiing or an attractive area for biodiversity (Mount Verde cloud forest) or paragliding, or hiking.
Sporting Events:
If the area has sporting events, then it is more likely to attract tourists.
Countries such as Barcelona are well known for football, thus people are willing to travel to Barcelona just to watch their football matches.
World Cup events- whenever a country is hosting the World Cup, they see an influx in the number of tourists.
Olympic Events- whenever a country is hosting the Olympics, they also witness an influx in the number of tourists.
Government Investment and Planning:
The government deliberately makes tourism a key aspect of its economic development.
They focus more on providing both primary and secondary resources to attract tourists and this makes such places hotspots for tourism.
Examples: Dubai, Saudi Arabia, and The Maldives.
In the case of Dubai, they believe that in the next few years, their oil reserves will run out.
Thus to maintain the level of economic growth, they decided to deliberately invest in tourism.
Factors influencing the sphere influence of different kinds of sporting and tourist facilities
Affluence:
If the citizens are high-income earners, they can afford to patronise sporting events through stadium attendance, television views, souvenirs etc.
And are more likely to support through these means.
Government and Private Investment:
Government investment in infrastructure to support sports development, meant to attract young people to a sporting event, is more likely to attract many teams from such cities or countries.
China, for example, is investing heavily in football infrastructure.
Growth in popularity:
Well-known sports have a higher sphere of influence than sports that are not well-known.
Advertisement and marketing in new areas:
When a football club advertises its souvenirs and events in new areas, it increases its supporter base, hence its sphere of influence.
Also, rich clubs like Manchester City or Man U, Chelsea etc have been known to tour places such as China and the United States to play games and market merchandise.
Increased wealth and development in the country:
The country can invest in infrastructure that will attract more people to the country
The impact of global competition:
If the clubs play or compete at international levels, their sphere of influence increases
Increased exposure to different media as a result of an increase in technology:
The media in the form of TV, radio and the internet can beam live matches to a large number of viewers all over the world.
This increases the sphere of influence of the sport. Sports such as Football, tennis etc.
Greater population mobility.
Certain factors affect the location of teams and the distribution of supporters:
Population density:
The population is important because it is the people in the settlement that will patronize the club to enable them to get revenue and run the club
The level of income of the residence:
Clubs are usually located in places where fans have a reasonable level of income to be able to buy the tickets to support the clubs
The demographic composition of the population:
Certain sports are located in areas that require a certain age bracket of supporters.
A good example is soccer which requires a largely youthful and working population rather than an aging population while golf requires a larger working and ageing population.
The presence of certain physical activities (topography):
The topography or landscape will determine the location of certain sports or teams.
Example: beach soccer can only be played in coastal areas
The level of infrastructure in the area:
The road networks, stadiums, airports and anything that facilitates the movement of people to and from the area determines the location of a sports team
When the town is politically stable, teams will be located in the area since the teams need peace to thrive.
Government and private investment in infrastructure to support sports development that is meant to attract young people to a sporting event are more likely to encourage teams to emerge from sub-cities or towns.
Cultural and historical factors:
If a country is noted for competing in an event, it will tend to have a large number of clubs.
Example: England has long been noted as a soccer country
Proximity to competing teams:
The essence of being a sporting team is to compete with others for a grand prize.
As such, teams would be located in towns that have other teams.
This reduces the cost of travel, as the teams do not have to go over long distances to play with others.
In Ghana, for instance, the Kpando Hearts of Lions, the only team in the Volta Region migrated to Accra.
3. Tourism and sport at the international scale
Niche tourism strategies
Adventure tourism:
the tourists travel to remote areas or physically challenging environments that are sometimes dangerous to the tourists
Examples:
Travels to Mt Everest, Nepal
Visit to Antarctica
Sahara Tour
Mariana Trench
Extreme environment tourism:
involves dangerous landscapes often with a difficult climate, and remote places that are sparsely settled or not occupied at all
Characteristics of extreme tourists are that they are without children, have high-paid jobs/good income earners etc.
Movie location tourism:
takes place in areas where popular movies have been shot
Examples:
Lord of the Rings acted in New Zealand
Game of Thrones in Northern Ireland
The Hobbit in New Zealand
Theme parks such as Disneyland have created a setting that looks like the movie to attract viewers
Heritage tourism:
travel to experience the place, artifacts, historic sites or indigenous people
sometimes referred to as historical tourism.
Advantages of Niche tourism:
It is environmentally friendly, as it causes less pollution due to the limited number of people involved
It benefits the local population
Tourists can maximize the benefits of their tourist experience
Disadvantages:
It can be dangerous because it sometimes involves extreme and risky activities
It can be expensive
They are more likely to be exposed to various attacks by criminals
Advantages of Mass Tourism:
Travel in large groups thus it is safer.
It is cheaper because the cost is shared among everyone.
It boosts socialization because the tourists travel with people they are familiar with
It is well organised.
Disadvantages:
It is expensive in the long term because some travel and tourism agencies take advantage of the tourists.
Tourists are sometimes forced to visit places they might not want to visit.
It may lead to environmental degradation: noise pollution, water pollution, air pollution etc
Mass tourism may sometimes lead to terrorist attacks.
Economic benefits of tourism to SIDS
Increases the GDP of a country directly and indirectly through the ‘multiplier’ effect.
Multiplier effect: this means that the revenue obtained from the tourism industry could benefit other industries which could yield further income in other industries.
Taxes increase government revenue.
The government obtains tax from the tourists which can be used to invest in other projects in the country such as schools.
Increase the foreign exchange earnings of a country.
This can help to stabilise the country’s currency.
Can be used to import technology and machinery, and invest in other industries through foreign direct investment.
Creates employment for the local people.
Economic costs
This may divert government attention from needy areas of the economy such as education and health.
Requires government expenditure on tourism: The government would have to spend a lot of money providing good roads etc.
Profits may go overseas – In the form of ‘leakage’.
Leakage: when the profit is taken outside the country.
The spread effect is limited and may therefore cause regional inequalities.
It may only bring about regional development and not national development.
Inflates prices for land, housing, food and clothing.
Social benefits
May enhance the role and status of women in society.
How foreigners behave with their wives would usually influence how people in, for instance, LICs would treat their wives.
Encourages female education.
Saves the indigenous culture of the people due to tourist interest in them.
Increases international understanding of diverse cultures.
Culture exchanges stimulate broadening horizons.
Social costs
The breakdown of traditional family values creates a materialistic society.
Social pathology, including an increase in prostitution, drug use and petty crime.
Mass tourism may lead to resentment from the host population
Westernization of culture may lead to the depletion of the cultural heritage of the local people.
Environmental benefits
Improvement in landscape and architectural standards
The establishment of nature reserves and national parks protects the environment.
Promotes interest in monuments and historic sites which encourages preservation and maintenance of the sites.
Environmental costs
Tourist complexes do not reflect local architecture
The natural environment and wildlife habitat could be destroyed to allow for the development of secondary tourist facilities such as hotels, nightclubs etc.
Excessive pressure leads to air, noise and visual pollution
Traffic congestion and pollution
4. Managing tourism and sport for the future
Four types of carrying capacities:
Environmental/physical carrying capacity limit of a site beyond which wear and tear will start taking place or environmental problems will arise.
Perceptual / Psychological carrying capacity –The lowest degree of enjoyment tourists are prepared to accept before they start seeking alternative destinations.
Economic carrying capacity –The ability of a tourist site to absorb tourism activities without displacing or disrupting desirable local activities.
Social carrying capacity –The level of tolerance of the host population for the presence and behaviour of tourists in the destination area, and/or the degree of crowding users (tourists) are prepared to accept by others (other tourists).
Factors affecting carrying capacity in a tourist destination:
The fragility of the landscape to development and change
Fragile landscapes are more likely to be destroyed by a large number of tourists.
This implies that there must be a limit to the number of tourists who can visit such destinations, so as not to exceed the capacity.
The level of tourism development and infrastructure.
If development is rapidly taking place in an area without any effort to sustainably maintain the vegetation, it could lead to deforestation.
In this case, the carrying capacity has been exceeded.
The level of organization of the destination’s management.
The existing level of exposure of cultures and communities to outside influences and lifestyles.
If the local people in the tourist destination are exposed to other cultures (dressing, music etc) they are more likely to accommodate the tourists without complaining.
However, if they are less exposed to other cultures, then they are more likely to complain about it and their social carrying capacity will be excluded.
Level of economic divergence and dependency upon tourism.
If the tourist destination depends heavily on tourism, then the carrying capacity is likely to be exceeded.
However, if the destination has other sources of income, the local people are more likely to place strict rules on the number of tourists who can visit the destination.
The level of employment and poverty.
If local people in the tourist destination are gainfully employed they are more likely to impose strict laws on tourist numbers.
On the other hand, if the people are unemployed they are more likely to exceed the carrying capacity to cash in on large tourist numbers.
The number of tourists.
Type of tourists and their behaviour.
Sustainable tourism
Economic sustainability:
The livelihood of the local people is maintained.
With the development of tourism, the locals will benefit either through trade or by direct involvement in the industry.
Tourist revenue is sufficient to cater for the cost of repairing the facilities to maintain their quality
Tourism is managed such that tourists are encouraged to visit during off-peak periods to avoid excessive damage to the natural resources
Resources used for the construction of buildings and infrastructure are obtained locally. They are used with care to avoid waste
It involves undertaking effective research and development to obtain relevant data on tourist numbers and total revenues as well as new ways to improve the tourist facility
Environmental sustainability:
It minimizes environmental damage to the ecosystem to maintain the flora and fauna of the tourist destination.
For example, hunting and loud noise threaten the stability of the ecosystem and, therefore, are not permitted.
Tourism converses with the natural environment through the creation of nature parks and game reserves.
Waste is minimized and disposed of sustainably and traffic is managed in ways that minimize environmental pollution
Social Sustainability:
Tourist information bulletins and guidelines are published to stress the importance of sustainable practices in the tourist destination
The staff are trained on issues of sustainable tourism management to enable them to embrace the concept of sustainable tourism
The local community forms an integral part of tourism development and must benefit from tourist activities in the area
Tourism supports local communities by providing opportunities for the local economy to benefit socially and economically.
Butler’s tourism model:
Exploration: A new destination, with very few visitors.
They are usually adventurous travellers who have minimal impact.
Involvement: If the tourists like the new destination and the destination are happy to receive tourists, then there may be an investment in tourist infrastructure and involvement by locals.
Tourist numbers grow slowly.
Development: Tourism becomes a big business with further investment and involvement by TNCs.
Holidays become more organised with package holidays arriving.
Consolidation: The area becomes reliant on tourism.
Advertising and marketing attempt to maintain and increase tourism levels.
Facilities like beaches, swimming pools and golf courses may become the domain of tourists causing some local resentment.
Stagnation: There is some local opposition to tourists, there is no new investment, tourists become tired of the same destination and growth stops.
Rejuvenation: Tourism is relaunched through advertising, tourist arrival from new markets increases, new transport links are opened or tourism becomes more sustainable with local involvement.
OR
Decline: There is no relaunch, locals remove their support, TNCs leave and tourism begins to decline.
Urban Environments
1. Introduction to Urbanization
Urbanization is the process of population concentration into cities.
This phenomenon has been a defining characteristic of human development over the last century.
Understanding the factors that drive urbanization is crucial for comprehending the challenges and opportunities posed by the urban environment.
Key Concepts:
Urbanization:
The increasing concentration of populations in urban areas.
Rural-Urban Migration:
The movement of people from rural areas to urban centres.
Push and Pull Factors:
Forces that encourage people to leave rural areas (push) and attract them to urban areas (pull).
Causes of Urbanization:
Industrialization:
The shift from agrarian economies to industrialized societies often leads to the growth of urban centres.
Employment Opportunities:
Cities offer diverse job opportunities, drawing people seeking employment.
Technological Advancements:
Improved transportation and communication contribute to increased urbanisation
Urbanization:
Site: actual land on which a settlement is built; situation: r/s w/ its surroundings
Desirability enhanced with physical, social and economic factors (esp w/ industrialization and trade)
Industrial, service (recreation or transport)/residential role (incl open space) can change in proportion over time
Agricultural roles → steadily diminished in urban areas
Mostly in rural areas where population density is low
Industrialized areas with good access to resources
develop to become cities
Vertical Zoning: same building is used for 1 function:1 floor and another function on another floor to make up for the lack of space in urban areas
Range: max distance people are prepared to travel for G&S
Threshold: minimum number of people required for a G&S to stay in business
Sphere of Influence: area served by a settlement
Low-Order Goods: necessities (need only a small hamlet - dispersed, individual households w/small population to support) → limited range
High-Order Goods: luxuries (shared by a few villages due to specialization) → larger population
Conurbation: ≥ 2 cities merge, millionaire city & megacity,
Metacity: large-scale city regions
Megalopolis: cities sprawl and merge into 1
Large urban areas provide large number of high-order and low-order goods to a large population
Megacities:
Dominated by young adults (migrate searching for jobs) → high birth rates
Rapid EG and urbanization → large generation of wealth and large scale of environmental impacts new forms of planning and management to cope
Urban Growth and Economic Development:
Correlation between urban growth and ED
Commercial, industrial, political, administral and social function
Stimulus for development, EOS for health and education, ethnic, tribal and religious intermixing → weaken ties to traditional rural beliefs and customs
Cannot cope w/ growing population
high rates of unemployment
overloaded & overcrowded
transport systems
air, water and noise pollution
insufficient housing, sanitation and water supplies
deteriorating infrastructure and shortfalls in service delivery
Growing inequalities in access to infrastructure and services due to income gap → increased prevalence of social problems
Many health issues occur as an indirect impact ⇒ decline in quality of life
Urban Settlement Functions:
Trade and comms, mining and industrial areas, tourist resorts, govt services and high-tech industries (administrative center)
Settlements in favored areas have greater growth potential and a greater range of services and functions (may change over time)
Lowland coastal plains w/ links inland
Vance: development of settlements occurred as a result of trade interactions (external influences → centers of innovation for external commercial forces
Losch: cities grow due to transport accessibility that plays a large role in efficiency and can produce corridors or urban areas
Build new towns and new capital cities to deflect growth to accommodate the overspill population and ease chronic overcrowding + redistribute the state's wealth
Relocation of people to ensure their environment for living and working is ideal
Factors of Urban Economic Activity Patterns:
Bid-Rent Theory: limited land at the city centre that is most expensive as it's the most accessible land to public transport
Secondary peaks at intersections of main roads and ring roads (multi nuclei) & increased use of private transport in inner city areas
Low-Order Goods: neighborhood stores and shopping parades (shop clusters)
High-Order Goods: high street shops, dept stores
Out-of-Town Superstores and Retail Parks: large outlets close to residential areas
Congestion and inflated land price in city center → sub & counter-urbanization (increased accessibility to these sites) of more affluent households
Changes:
Economic change → more women in paid work → increased standard of living & car ownership
Demographic change → smaller households, more elderly → online shopping
Tech change→ more families own deep freezers (don't need to shop daily)
closure of high street shops due to changes in shopping habits (govt policies to revitalize retailing in central areas & inner-city redevelopment) - e.g. traffic-free zones
Leads to decentralization of other commercial activity and business parks in suburban sites
Central Business Districts: commercial and economic core of a city (coincides with/ place of peak land value)
Industrial Zones: inner-city areas and brownfield suburban sites (near airports) away from residential areas (pollution)
Those needing skilled labor, access to CBD and urban market for distribution
Cities are major centers of innovation, ideas and fashion → manufacturing centers + access to international market through a variety of labor (skilled and unskilled) → large markets
Planning urban economic activities: restrict development in particular areas (pollution)
Factors Affecting Location of Urban Areas:
Rich | Poor |
places with/ pleasant views and offer recreational activities → high ground that's safe and building standards account for risks | forced to live in areas of steep relief and be at risk of mass movements (informal housing) not protected against hazards |
increased use of private transport → edge of town areas are more accessible | located near city centre as it's close to jobs and they cannot commute from outer areas (live in overcrowded rooms as rent is expensive) |
may resist development of socially affordable housing / move to outer suburbs if this happens | |
can choose where they live and are more willing to pay for the housing → occupy higher-quality land ⇒ private developments prefer this |
Ethnic groups choose to live together for bonding and people to rely on (+ve segregation)
-ve segregation: certain groups excluded from certain areas (legally) - apartheid
Multiracial policy of locating all racial groups target on housing estate for racial harmony
Planning to achieve a balanced social mix (housing types and people)
People in rich neighborhoods may resist development of socially affordable housing / move to outer suburbs if this happens
Priv developments favor the rich: can choose where they live and are more willing to pay for the housing → occupy higher-quality land
Urban Poverty, Deprivation and Informal Activity in Urban Areas:
Deprivation can be measured through physical, social, economic and political indices
Slum: group of individuals living under the same roof in an urban area lacking ≥ 1: durable housing (protection from extreme climatic conditions), sufficient living space (max 3 in a room), access to improved water (sufficient, affordable, obtained w/o extreme effort), access to sanitation facilities, secure tenure (protection against forced eviction)
Dual Economy: mix of formal (foreign owned, more elite) and informal economic activity (small scale, labor intensive, locally owned)
Bazaar Economy: small trade and service establishments (family enterprises) - intense competition keeps prices low and supports a low standard of living
Street Economy: low earnings and standard of living (street hawkers, beggars, prostitutes)
Informal economy relieves the economic problems of the poor by using their energy and small-scale assistance to improve circumstances
Informal economy allows exploitation of the poor by the rich (cheap labor to keep cost of production down)
2. Urban Patterns and Land Use
Understanding the spatial organization of cities is essential for analyzing the urban environment. Urban patterns and land use are influenced by historical, social, and economic factors.
Key Concepts:
Land Use Zones: Areas within a city with specific functions, such as residential, commercial, industrial, and recreational zones.
Central Business District (CBD): The core of a city, usually characterized by high-density commercial and office buildings.
Residential Areas: Spaces dedicated to housing and accommodation.
Industrial Zones: Areas designated for manufacturing and industrial activities.
Urban Patterns:
Concentric Zone Model: Developed by sociologist Ernest Burgess, this model envisions a city with concentric rings, each representing different land use zones.
Sector Model: Proposed by Homer Hoyt, this model suggests that cities develop in pie-shaped sectors based on transportation routes.
Multiple Nuclei Model: Developed by Chauncy Harris and Edward Ullman, this model argues that cities have multiple centres of development.
Challenges of Urban Land Use:
Urban Sprawl: The uncontrolled expansion of urban areas into surrounding rural landscapes.
Gentrification: The transformation of a neighborhood through the influx of more affluent residents and businesses.
Urbanization, Natural Increase and Population Movements
Increase in the proportion of people living in urban areas caused by rural-to-urban migration, higher rates of natural increase in urban areas, reclassification of rural areas as urban ones
Cycle of urbanization, suburbanization, counter-urbanization and re-urbanization
Natural increase & birth rates
Rural-Urban Migration: movement of people away from countryside to towns and cities (people believe they're better off in urban areas)
Push and pull factors
Gentrification: reinvestment of capital into inner-city areas (residential and commercial areas)
Social displacement of poor people: house prices rise poor cannot afford and move out → young mobile population takes their place
Re-Urbanization: revitalization of urban areas and a movement of people back into these areas
Suburbanization: outward expansion of towns and cities (town extensions and increased scope of public transport)
Low IR → lower cost of living + willingness of local authorities to provide utilities - improved public transport → expansion of building societies
Counter-Urbanization: movement of population away from larger urban areas to smaller and newer towns on the edge of city limits
Due to high land price and crime rate, congestion, pollution, lack of community and declining services in urban areas
Urban Sprawl: uncontrolled growth of urban areas at their edges (prevented by green belts)
Urban system growth → increased need to provide access to clean water, sanitation and waste disposal → increase risk of diseases and burden on authorities
Expand transport facilities and telecom networks to attract new economic activity and match pop growth w/ infrastructure growth
The Causes and Consequences of Urban Deindustrialization
Long-term decline in employment in the manufacturing sectors of an economy → job loss
+ve: industries reduce workforce to increase productivity thru rationalization and mechanization → more competitive
Overseas competition from newly industrialized countries (NIC)/introduction of rival product → fall in DD → rationalization (cost cutting and decrease labor → unemployment)
Exhaustion of resources → increasing costs of raw materials/lack of capital - automation and new tech take over
Removal of subsidy/imposition of tax → higher COP (lay off workers to maintain profit)
Gains in service sector but cannot compensate for manufacturing loss
New jobs (part-time and low paid) mostly taken by women - older firms → less competitive and less innovative (unskilled labor)
Areas of disinvestment (massive outflows of capital and labor - filled by commuters from outside the city areas)
Reindustrialization: growth of high-tech industries, small firms and services
3. Urban Challenges and Solutions
The rapid growth of cities presents numerous challenges that require innovative solutions. Understanding these challenges is crucial for sustainable urban development.
Key Concepts:
Sustainability: Meeting the needs of the present without compromising the ability of future generations to meet their own needs.
Infrastructure: The fundamental facilities and systems serving a city, including transportation, water supply, and energy networks.
Challenges:
Traffic Congestion: The result of increased urbanization, inadequate transportation systems, and a growing number of vehicles.
Housing Shortages: High demand for housing can lead to shortages and increased prices.
Environmental Degradation: Urbanization often results in pollution, deforestation, and habitat loss.
Social Inequality: Disparities in income and access to resources can lead to social unrest.
Solutions:
Smart Cities: Integration of technology to improve the efficiency of urban services.
Mixed-Use Development: Combining residential, commercial, and recreational spaces to reduce the need for extensive transportation.
Green Infrastructure: Incorporating natural elements into urban planning to promote environmental sustainability.
Urban Microclimates
Structure of air above urban area and structure of the urban surface
Radiation and sunshine: industrial haze → reduced visibility ; greater scattering of soil water retention by dust & higher absorption of longer waves due to surfaces & CO2 → more diffuse sky radiation
Also heat produced by human activity
Summer: higher incidence of thicker cloud cover vs winter - increased convection and air
Pollution: higher incidence of radiation fog and smog
Concentration of hygroscopic particles increased condensation + higher day temps
Urban pollution and photochemical smog trap outgg radiant energy
Temperature: more heat energy retention and release → heat islands ; heating from below → increased air mass instability overhead ; big local contrasts btw sunny and shaded surfaces
Pressure and winds: severe gusting and turbulence around tall buildings → strong local pressure gradients from windward to leeward walls; canyon effect: deep, narrow streets are much calmer
Turbulence of air may be reduced overall
Higher building height and urban surface roughness → lower wind speed
Lack of avail moisture and higher temp: decrease in RH
Greater instability and stronger convection above built-up areas → higher incidence of thunder and more intense storms & less snowfall and briefer covers
Burning fossil fuels (domestic & commercial use): exceed energy inputs from sun
Buildings have a lower albedo: higher capacity to retain and conduct heat
Surface character, rapid drainage and lower wind speed: reduction in heat required for evapo(transpi)ration
Also changes airflow patterns → reduction of heat diffusion
Fewer open H2O bodies → less evaporation and plants → less transpiration
Urban area is warmer than surrounding rural area especially by dawn during anticyclonic conditions (calm, high pressure)
Develop pollution dome w/ cooler air above it that prevents pollutants from dispersing (day: prevent incoming radiation, night: prevent LWR from escaping → small temp diff)
Air Pollution Patterns
Pop growth in urban areas → industrial development energy and heating → increased air pollution → increase in no. of vehicles and DD for
Indoor air pollution: burning of firewood and paraffin (DCs) for cooking and heating as they do not have as much resources to cope w/ pop growth and provide services
LICs and NICs: weaker economies → minimal I in pollution control + use cheap, inefficient energy resources and cannot tackle air pollution effectively
Worsened by expanding car industries for ED (increased private car ownership)
Roads are also in a poor state which reduces the quality of vehicles
Pollution Management Strategies
Use more energy-efficient tech, public transport, car pooling schemes, cycling/walking → burn less fossil fuels
Use catalytic converters (reduce emissions of NOx)
Raise enforcement of emission standards (cheaper to lower emissions than clean up pollution)
Green spaces can reduce the effects of urban heat island (increased evapotranspiration → lower temperature → lower energy use), noise levels and air pollution
Tree shade has great cooling potential and improves air quality
Traffic Congestion Patterns, Trends and Impacts
More congested on weekdays, start of sch year, festivals and national holidays
Weekdays: morning and evening peak
Noise disturbance may cause people to move due to its associated health risks
Contested Land
2016 Rio de Janeiro Olympics: property boom in central favelas (drug gangs eliminated) displaced people for games-related purposes
Occupy movement: anti-capitalist protests to bring attention to the huge profits and inequalities generated by the financial services
Dharavi, Mumbai: connected by all railways and is a potential intl business destination → could be developed into a financial/service district but would displace 1m ppl
Slum: means of escaping poverty, home to thousands of micro-industries → attracts labor due to large informal economy
Depletion of Urban Green Spaces
Green spaces have little economic value and are not favored by developers yet is impt for physical and mental well-being
Increased thru compensatory afforestation projs but does not serve to decrease air or noise pollution (QOL factors)
Urban Crime
Crime hotspots: residential areas w/ lack of health centres, schs, recreational areas and police stations → easy access and lack of security
Areas w/ high no.s of offenders and crime targets commit crimes → increase incentive and ability to
Increase surveillance (more police officers on patrol and more CCTV use):
Improved street lighting and buildings designed to reduce dark areas
More taxi services during closing time of clubs and women-only taxis
Adopt a 0-tolerance policy towards crime
4. Future Trends in Urbanization
The future of urbanization is shaped by ongoing trends and emerging challenges. Analyzing these trends allows for proactive planning and sustainable development.
Key Concepts:
Megacities: Extremely large cities with populations exceeding 10 million people.
Rural-Urban Continuum: The idea that rural and urban areas exist on a continuum rather than as distinct entities.
Challenges to Address:
Overpopulation: Managing the strain on resources and infrastructure caused by rapid population growth.
Digital Divide: Ensuring equitable access to technology and information in urban areas.
Resilience Planning: Developing strategies to withstand and recover from natural disasters and other shocks.
Future Trends:
Smart Urbanization: Continued integration of technology to enhance urban services and improve quality of life.
Climate Change Adaptation: Cities must adapt to changing climatic conditions, including rising sea levels and extreme weather events.
Rural Revitalization: Efforts to balance urbanization by promoting development in rural areas.
Understanding the multifaceted nature of urban environments is essential for informed decision-making and sustainable development in an increasingly urbanized world.
Resilient City Design:
Cities are productive, innovative and trading centres that benefit from EOS and experience rapid pop growth
Also manifest major inequalities and deal with air and H2O pollution, congestion and inflated land prices)
Properly functioning transport network and energy, H2O and waste infrastructure for social mobility (reduce ecological footprint and vulnerability to pollution)
Dense population: less CO2/capita and higher potential for public transport → savings in heating and cooling as emissions/person decrease
Minimize travel dist→ use less space and infrastructure → reduce urban sprawl
Reliable SS of clean H2O and housing at an affordable and acceptable level
Clean up derelict sites to create more open spaces
Generating energy from waste (sell electricity back to urban grid): don't waste landfills
Prepare for intensified and more frequent weather events to reduce impact and recovery cost
Safer buildings and zoning (prevent building in unsafe areas), maintenance of sea walls and make the change to adopt cleaner energy
Eco-City Design
Eco-city: minimal environmental impact
Conserving non-renewables (reduce fossil fuels) and using more renewables → maintain acceptable waste production levels
Provide sufficient green spaces by reusing and reclaiming land
Encourage active involvement of the local community
Beddington 0 Energy Development (BedZED): environmentally friendly housing development in London - lower car mileage, space-heating requirements, hot H2O consumption, mains H2O consumption and electric power
C40: address climate change by working tgt to share technical expertise and best practice
Improve public transport, make infrastructure and H2O SS more reliable and efficient and more efficient outdoor lighting (lower energy consumption), make homes and offices more energy-efficient (save $ and the environment)
Consider social equity so that low-income communities can benefit as well
Bolivia's cable cars (El Alto - La Paz): affordable public transport route over a winding, congested highway
Helsinki and Hamburg: people powered mobility → provide cheap, flexible and well coordinated transport system that's competitive w/ private car ownership + increase pedestrian and cycle paths to eliminate the need for cars
Smartphone app: journey planner and payment mtd (limit users)
Smart Cities
City that is performing well in the economy, environment, people, governance, mobility and living conditions → I in social, human and physical capital (incl ICT) → sustainable development and high QOL
Good way to manage resources avail to the city (rising pop and dwindling resources)
Increased reliance on availability and quality of infocom tech and social infrastructure (intelligence and skills for urban competitiveness) → high proportion of educated workers
Need not be entirely new: can be readapted and upgraded from existing cities
Global Interactions
Changing Global Interactions and Power
Definitions:
Globalization: “the growing interdependence of countries worldwide through the increasing volume and variety of cross-border transactions in goods and services and of international capital flows, and more rapid and widespread diffusion of technology”(International Monetary Fund).
Globalization: It is a term that was invented to emphasize that the globalization of a product is more likely to succeed when the product or service is adapted specifically to each locality or culture it is marketed.
E.g., the presence of McDonald’s restaurants everywhere on the globe = globalization and the changing menus of the restaurants to appeal to the local tastes = globalization
Transnational Corporations (TNCs): Companies with branches in many parts of the world eg. Coca-Cola, Apple, MacDonald’s etc
The drivers of globalization:
Transportation improvements:
For example, faster and bigger aeroplanes enable labour and goods to move easily from one place to another; road transport network improvements have allowed for cheaper means of moving goods and people; sea transport – larger container ships – facilitates the transportation of large volumes of goods.
Freedom of trade:
For example, the EU, NAFTA, ECOWAS AND COMESUR have all contributed to allowing the free movement of goods, services, ideas and labour between member countries and across regional boundaries.
Improvements in communications:
E.g., improvements in telecommunication and the Internet have contributed to the exchange of ideas and services through the Internet.
Cheap Labour in developing countries – This is also aided by technology, for example, through outsourcing.
This makes it possible to outsource services to labour in different parts of the world.
Eg. Marking IB scripts online by different examiners in different parts of the world.
The drivers of globalization:
The KOF Index
The KOF Index of Globalization was introduced in 2002 (Dreher, 2006). KOF is a Swiss Institute of Business Cycle Research.
The overall index covers the economic, social and political dimensions of globalization.
Economic globalization is characterized by long-distance flows of goods, capital and services as well as information and perceptions that accompany market exchanges;
Political globalization is characterized by a diffusion of government policies.
Social globalization is expressed as the spread of ideas, information, images and people.
A.T Kearney Index
AT Kearney is a management consultancy firm that advises large corporations on international competitiveness.
Founded in 1926 in the US (Chicago), it publishes its index in the Foreign Policy Magazine.
The AT Kearney Foreign Policy index assesses the extent to which the world’s most populous nations are becoming more or less globalised, using twelve variables, which are subdivided into four “baskets” of global integration
Human and Physical Influences of Global Interactions
Political factors that affect global interactions:
Multi-governmental Organizations
MGOs are organizations or countries that come together to form a single entity mostly for trading purposes. Eg.
EU- European Union
USMCA- United States Mexico Canada Agreement
SADEC- South African Dev`t committee
UEMOA-West African Economic Monetary of Africa
ASEAN
MGOs allow state boundaries to be crossed feely to facilitate the free movement of goods, services, finance, and ideas.
Members are encouraged to abolish tariffs and promote the exchange of ideas in areas of security, trade, etc
Ways by which MGOS can promote global interactions
They promote the free movement of people between countries.
For instance, in the EU and ECOWAS people can move freely thereby we can say they are practising globalization.
Free trade allows the free movement of goods between member countries.
It promotes global interactions because it leads to the development of homogeneous landscape-saving brands, banks, etc.
Some of the MGOs use a common currency, which allows the free flow of goods and services.
This common currency unites those countries, such as the Euro-using countries, financially.
MGOs sometimes have common policies that facilitate global interactions.
For instance, CAP (Common Agricultural Policies) in the EU helps farmers in all EU countries to increase agricultural output by receiving support in the form of subsidies from the EU and guaranteed markets.
Membership in MGOs facilitates global interactions through the free movement of capital between member countries.
This means banks can transfer money at no cost from one country to the other.
Free movement of ideas between members as a result of the Internet.
For instance, if you are a member of the EU, you cannot be charged for roaming charges if you visit another EU country.
This does not always lead to global interaction because:
Joining groups like the EU means you would be unable to be independent as their currency is even controlled by the EU’s central bank.
Foreigners would dominate the countries.
How can export-processing zones facilitate global interactions?
Export processing zones allow countries to have access to goods that they cannot produce on their own at relatively low prices.
Free zones also help in global interactions because they help in the transfer of skills from advanced countries to developing countries through the training of workers.
Free zones help to stabilize a country’s currency against other countries’ currencies.
This improves global interactions because the country would be able to trade with another country, like the US, and get a lot of the foreign currency into their country.
Export processing zones lead to bilateral and multilateral relations between countries, which enable manufacturing companies to sell their goods to different parts of the world.
Development Opportunities
The multidimensional process of human development and ways to measure it:
UN Sustainable Development Goals criteria
Goal 1 – No poverty
Goal 2 – Zero hunger
Goal 3 – health and well-being
Goal 4 – Quality education
Goal 5 – Gender inequality
Goal 6 – Clean water and sanitation
Goal 7 – Affordable and clean energy
Goal 8 – Decent work and economic growth
Goal 9- Industry, Innovation and Infrastructure
Goal 10 – Reduce inequalities
Goal 11 – Sustainable cities and communities
Goal 12 – Responsible production and consumption
Goal 13 – Climate action
Goal 14 – Life below water
Goal 15 – Life on land
Goal 16 – Peace, Justice and Strong Institutions
Goal 17 – Partnership for the Goals
Human Development Index (HDI)
Developed in 1990 by the United Nations
The health dimension is assessed by life expectancy at birth
the education dimension is measured by the mean of years of schooling for adults aged 25 years and more and expected years of schooling for children of school-entering age
The standard of living dimension is measured by gross national income per capita
Scale of 0-1
gender inequality index (GII)
reproductive health, measured by maternal mortality ratio and adolescent birth rates;
empowerment, measured by the proportion of parliamentary seats occupied by females and the proportion of adult females and males aged 25 years and older with at least some secondary education; and
economic status expressed as labour market participation and measured by the labour force participation rate of female and male populations aged 15 years and older.
Changing Identities and Cultures
Cultural Diffusion
the spread of cultural traits from one place to another through the processes of cultural change.
There are several types:
Expansion diffusion – occurs when an idea develops in a source area and spreads into other areas while remaining strong at the source. E.g. spread of Islam from Saudi Arabia
Relocation diffusion – people who have adopted new ideas carry with them to a new location. E.g. Christianity to Africa from Europe.
Distance decay effect – The longer an idea takes and the further the distance it has to travel, the less likely it is to be adopted in new areas.
Adoption of mass culture – new cultural traits are taken in their entirety, perhaps abandoning old traditions
Adaptation/ Adaption of mass culture –cultural traits are modified so it can be accommodated within the context of an existing culture.
Cultural Hybridity– the extent to which different cultures are intermixed. Mixing of cultures can occur through; migration, media, transport revolution, Growth of global brands and even the internet
Cultural traits – characteristics of culture that give a culture its sense of identity – i.e what makes them different from others
Ethnicity – the shared sense of belonging to one ethnic group or another, based on ancestral lineage or cultural history.
Cultural diversity – the differences in cultural characteristics that are manifested in a given culture. Cultures that are not diverse tend to be homogeneous
Characteristics of a global culture:
Language
Dressing
Music
Movies/Television
Sport
Others(tourism, religion, education, architectural designs, etc.)
Barriers to global interactions:
Censorship of the Internet
The restrictions on migration to countries
Physical/environmental barriers
The resurgence of nationalism and anti-globalization movements
The double-edged effect of MGOs
Geopolitical and Economic Risks:
Threats to individuals and businesses include:
Hacking
Identity theft
The implications of surveillance for personal freedoms
Political, economic and physical risks to global supply chain flows
Environmental Risks:
Transboundary pollution (TBP) affecting a large area
Localized pollution resulting from the global flow of goods
Carbon footprints for global flows of food, goods and people
Polluting manufacturing industries
Food production systems for global agribusiness
Local and Global Resilience
Strategies to build resilience:
reject globalization
find ways of controlling the risks of globalization
adapt to the risks by implementing mechanisms to manage them in the event of their occurrence
The Geography of Food and Health
1. Measuring food and health:
Ways of measuring disparities in food and health between places:
Global Food Security Index (GFSI)
Takes into account four core issues of affordability, availability and quality of food across 113 countries
uses 28 indicators as a benchmark and goes beyond hunger in measuring food security
measures a country’s exposure to the impacts of a changing climate, susceptibility to natural resource risks and how countries are adapting to these risks
The Global Hunger Index(GHI)
Based on four indicators:
Undernourishment: the share of the population that is under-nourished
Child wasting: the share of children under the age of five who are wasted
Child stunting: the share of children under the age of five who are stunted
Child mortality: the mortality rate of children under the age of five
Calories per person/capita
measures the amount of energy contained in a given amount of food
measured in kilocalories per person per day (kcal/person/day)
High-calorie intake is associated with developed countries, and vice versa
Indicators of malnutrition
Stunted growth
Wasting
Undernourishment
2. Food systems and spread of diseases:
Sustainable Agriculture
The ability of a farm to produce indefinitely without causing harm to the ecosystem/environment
ensures that resources are used in such a way that future generations can still benefit from them
conserves natural resources
prevents environmental degradation
increases the profitability of the farm
The Environmental Costs of Increasing Food Production
The practice of monoculture by large TNCs causes significant damage to the natural environment.
The use of aggro-chemicals is harmful to the environment.
The cost of cleaning up chemical pollution is expensive.
It also leads to air pollution and greenhouse gas pollution from the farm.
Example: Methane.
It leads to the removal of hedgerows leading to deforestation.
Energy Efficiency Ratio:
measures the amount of energy input compared with the amount of output produced by the farm
two types of inputs: direct inputs and indirect inputs
Examples of direct inputs are planting, cultivation, labor, machinery, vehicle fuel, farm tools etc.
Examples of indirect inputs are fertilizers, electricity, irrigation, transport, pesticides etc.
The output-input ratio is calculated by dividing the total output by the total input
An efficient farm should have an EER≥1
Energy Efficiency Ratio=total outputs/total inputs
Factors affecting energy subsidies or energy efficiency ratio in different environments
Climate: Farms located in warm climates will need less energy than those in cold climates because colder ones need artificial light for crop growth.
Type of soil:
Loamy soil requires less fertilizer.
Sandy soil requires more fertilizer.
Type of crop cultivated: beans do not use a lot of nutrients. They fix nitrogen into the soil. Crops that produce protein require a lot of energy.
Relief/topography: When the land is relatively flat, it needs less energy, because it retains water and minerals easier.
Irrigation
The type of farming system: labor intensive or capital intensive
Two main improvements in physical processes that have led to an increase in food production:
Increased amount of farmland through converting brownfield sites and waterlogged areas to farmlands and cultivating forested areas. This has led to an increase in the amount of farmlands in Africa, Asia and other parts of the developing world.
The second reason is an increase in productivity, due to increased land size. The increase in agricultural productivity is the result of:
high-yielding variety of crops such as IR-8 rice and wheat. These crops have been genetically modified to increase the amount of output per hectare.
Mechanization of agriculture has made it possible for a large amount of land to be cultivated for farming
Use of chemical fertilizers. Despite its environmental impact, the use of agrochemicals has led to an increase in the amount of crop yield per land.
Irrigation has not only resulted in an increase in the amount of land needed to cultivate food, but it has also enabled experiencing seasonal rainfall to undertake dry season farming.
Rising incomes, leading to an increase in the demand for food and meat in MICs
Improved transportation, leading to an improvement in the distribution of food to areas experiencing food shortages
Better education, resulting in better food choices in favor of high-quality food
Mass media also plays a crucial role in determining the amount of food consumed by people in developed countries and urban areas
Disease/agriculture innovation diffusion can be classified into a number of types:
Expansion diffusion
occurs when a disease or agricultural innovation spreads from one place to another
the disease/innovation often intensifies in the originating region
as the disease/innovation expands into new areas, it is likely to weaken
recognized in the recent H1N1 flu that had its source in Mexico
Relocation diffusion
a spatial/geographic spread process
the disease/innovation leaves the areas in which it originated as it moves into new areas
Example: The migration of people with HIV or Measles
Network diffusion
occurs when the disease/innovation spreads through transportation and social networks
example is the diffusion of HIV which spread along important transport routes in Southern African countries with developed road networks, as well as social (sexual) networks
Contagious diffusion
spread depends on direct contact
mostly applicable to disease diffusion
the process is strongly influenced by distance because nearby individuals or regions tend to have a much higher probability of contact or infection (incidence of the disease) than remote individuals or regions
Hierarchical diffusion
involves the spread of disease through an ordered sequence of classes or places,
Example: from large cities to remote villages
assumed to be downwards from larger cities to smaller centres.
3. Stakeholders in food and health:
The following organizations have made significant contributions towards achieving the SDGs related to food security and diseases:
Food and Agriculture Organization (FAO):
Help eliminate hunger, food insecurity and malnutrition
Make agriculture, forestry and fisheries more productive and sustainable
Reduce rural poverty
Enable inclusive and efficient agricultural and food systems
Increase the resilience of livelihoods to threats and crises
World Food Programme
providing emergency assistance, relief and rehabilitation, development aid, and special operations
committed to ‘end hunger, achieve food security and improved nutrition by 2030‘
contributes to achieving this goal by providing food and food-related assistance to people in conflict-affected countries where people are likely to be undernourished
World Health Organization (WHO)
providing leadership on matters critical to health and engaging in partnerships where joint action is needed
shaping the research agenda and stimulating the generation, translation and dissemination of valuable knowledge
setting norms and standards and promoting and monitoring their implementation
articulating ethical and evidence-based policy options
providing technical support, catalyzing change, and building sustainable institutional capacity
monitoring the health situation and assessing health trends
How can TNCs or Agribusiness influence food consumption habits?
The production of food on a large scale by TNCs makes food available to areas that do not have sufficient food supply because the TNCs can export food to such hunger-stricken countries.
TNCs may sell food at a cheaper price to local consumers since they can reduce costs due to the large-scale nature of their operations.
By so doing, they are capable of producing more at a lower cost.
Since most foods produced by TNCs have preservatives, it increases the lifespan of food on the shelves.
This means that the consumer will not suffer from food shortages resulting from poor storage facilities or the perishable nature of the food.
TNCs also give consumers the opportunity of making food choices according to their preferences.
The wide range of options available means the consumer buy food that meets their dietary needs and food preference – key ingredients in the definition of food security
Criticisms of TNC/Agribusiness
At the input stage, the natural environment and natural breeding selection are losing out to genetically modified seeds.
Large land grabs by TNCs deny the people power to cultivate food for domestic consumption, possibly leading to food shortages
Food is preserved, processed package-branded and marketed such that food is becoming increasingly unrecognizable.
Example: it is becoming increasingly difficult to link processed meat products to the actual type of animal.
They may encourage or emphasise the growing of non-food cash crops rather than food crops which would limit the consumer’s choice of food.
TNCs often sell processed food, which has less fibre, thereby increasing the consumer’s risk of contracting diseases of affluence.
The Media and advertising companies can also present food adverts which present unhealthy food as suitable for consumers.
This could compel them to switch from eating healthy food to unhealthy one.
They may gain control of the supply of seed for one or more basic crops; this seed may then be priced beyond the means of the average farmer or the seed may require higher than affordable investments in infrastructure or equipment for high yields to be obtained.
4. Future health and food security and sustainability:
Possible solutions to food insecurity
Economic solution
Investment in agriculture:
financial investment such as agriculture subsidies given by the government could be given to farmers to increase food production.
Loans:
these could be micro-loans given to rural farmers at low-interest rates to invest in farming.
Food crop cultivation:
this will make food available for consumption, rather than investing in feed industries producing biofuels.
Commercial agriculture:
this will encourage large-scale farming of food crops that could potentially make food available at cheap prices or for export to increase the farmer’s revenue
Political solution
Food aid:
helps to alleviate food shortages because they serve as an emergency source of food during war or natural disasters like famine or drought
Fairtrade:
adopt policies that meet the livelihood of the people, respect/preserve their local culture and protect/use environmental resources wisely
Free trade:
an agreement between two countries to trade between themselves without any restrictions or barriers
Technological Solution
Irrigation:
to invest in dry-season farming/irrigation to provide water for crop farming and livestock production
Mechanization of agriculture:
investment in road infrastructure by extending feeder roads to farming areas, and providing tractors and other forms of farm machinery to farmers to cultivate crops on a large scale
Food waste reduction:
efforts must be made to reduce the amount of food waste generated in hotels, restaurants and supermarkets
Contemporary approaches to food production:
Genetically modified organisms (GMOs)
plants or animals whose genetic makeup(DNA) has been transformed by scientific engineering
leads to the development of a new organism whose DNA is different from the natural one
Vertical farming
the growing of crops vertically, in layers, especially in urban areas
beginning to gain popularity in the developed world, where food production is taking place in tall buildings in urban centres
In vitro, meat
also known as cell-cultured meat, clean meat or synthetic meat
the production of meat using tissue engineering technology
a cell is taken from a living animal and placed into a protein-rich liquid, causing the cell to grow without the need for the animal body
the cells multiply to produce artificial meat
not all forms of meat can be produced this way
Prevention and treatment in managing disease:
Two main systems of healthcare delivery:
Preventive Health Care:
Measures taken to prevent a disease from occurring as opposed to the treatment of a disease.
In other words, preventive health care emphasizes the need to prevent the incidence of the disease before it occurs.
Example: Polio vaccination takes place in Ghana every year to prevent the spread of polio among children.
Curative Health Care:
Involves treating the symptoms of the disease after the person has been infected.
Curative health care involves massive investment in medical infrastructure by the government in the form of hospitals, nurses’ training colleges and medical schools to train doctors as well as providing enough resources to make them functional.
Most countries in the world focus on curative health care rather than preventive health care.
Fieldwork
What is Fieldwork?
Fieldwork is a cornerstone of geographic learning. It's more than just studying textbooks or maps; it's about actively engaging with the world. Fieldwork allows students to step outside the traditional classroom walls and use this real-world environment as a laboratory.
There are three key aspects to fieldwork:
Observation: Hone skills to identify and record geographical data. This data could include anything from landforms and vegetation to human settlements and infrastructure.
Recording: The information gathered needs to be documented. This might involve taking notes, sketching maps and diagrams, or even capturing photographs and videos.
Analysis and Interpretation: Once data is collected, it is analyzed and interpreted to understand the relationships between humans and the physical environment. This analysis could involve identifying patterns, trends, and cause-and-effect relationships.
By combining these elements, fieldwork allows one to learn about geography and experience it firsthand. Students can see how geographical theories studied in class play out in the real world.
Identifying a Fieldwork Topic
Choosing the right topic is crucial for a successful fieldwork project. Here's a breakdown of the key characteristics to consider:
Short and Precise: Keep it clear and concise. The topic should clearly state what is being studied and where. It should be easy to understand at a glance.
Researchable and Clear: Make sure there's enough information available to gather and analyze. A topic that's too broad or lacks sufficient data will be difficult to investigate effectively.
Geographically Relevant: Remember, geography is all about the relationship between humans and the physical environment. The topic should focus on this connection.
Unambiguous: Avoid topics that could be interpreted in multiple ways. A clear and well-defined topic will lead to a more focused and insightful study.
For example, instead of a broad topic like "Urbanization", a more focused and geographically relevant option could be "The impact of urban sprawl on green spaces in [City Name]."
Formal Requirements
There are specific formatting and presentation guidelines for the fieldwork report. These ensure clarity, consistency, and proper referencing of work. Here are some key points to remember:
The IA must not exceed 2500 words. Only footnotes of less than 15 words and text boxes with less than 10 words in them, the bibliography, and appendices are excluded from the word count.
The IA is a piece of fieldwork based on primary data.
The topic must relate to the syllabus and have a spatial element to it.
It must be on a local scale, but not necessarily close to the local area of the school.
Two or three hypotheses are recommended.
Good map work with annotations and photographs that help to give locational context is recommended.
It may be a good idea to use double spacing for your writing - check with a teacher.
If using questionnaires, avoid questions that give Yes/No answers as this will limit the way data can be presented. Avoid long qualitative answers which will impinge on the word count.
Creative presentation of data is rewarded, including hand-drawn graphs and charts.
The focus of the write-up is the analysis, purely descriptive work will not produce high grades.
Teacher support is vital. Seek advice from your teacher for completion of your work.
Academic honesty is of the utmost importance - use consistent, clear referencing.
Formulating Objectives
Objectives are like mini-goals for the fieldwork project. They provide a clear direction for the research and help stay focused. Here are some key characteristics for effective objectives:
Specific: Clearly state what the aim is to achieve with the fieldwork. Don't use vague terms like "understand" or "learn more about." Be specific about what aspects you want to understand or learn.
Measurable: How will you know if you've achieved your objectives? Formulate them in a way that allows you to measure your progress and evaluate the success of your fieldwork.
Focused and Narrow: Don't try to cover too much ground. Keep your objectives focused on a specific aspect of your chosen topic.
Realistic and Achievable: Be realistic about what you can achieve within the timeframe and resources available for your fieldwork.
Logical: Structure your objectives in a logical flow. Typically, they start with understanding the location and background, then move on to specific aspects, and finally consider future prospects.
Related to the Topic: Don't simply repeat your topic in your objectives. They should elaborate on what you'll be investigating within the broader topic.
For example, an objective for the topic "The impact of urban sprawl on green spaces in [Your City Name]" could be: "To analyze the change in green space coverage within a specific district of [Your City Name] over the past decade due to urban development."
Data Collection Methods
There are various tools and techniques that can be used to gather data during fieldwork. Choosing the right method depends on the specific topic.
Here's a closer look at some common data collection methods used in geography fieldwork:
Observation:
This is a fundamental skill in geography. It involves using your senses to actively record information about the environment. Here are some things to keep in mind:
Advantages: Useful in situations where interviewing isn't feasible, allows for studying natural processes as they unfold.
Limitations: Can be subjective (influenced by your own biases), and limited in scope for large areas or complex phenomena.
Interviewing:
Talking to people directly can provide valuable insights and perspectives.
Advantages: Offers first-hand information from people who live or work in the area you're studying.
Limitations: Interviewer bias can influence responses, and language barriers may be a challenge.
Recording:
This involves capturing information in a permanent form for later analysis.
Advantages: Creates a lasting record of your observations, and allows for organization and presentation of data.
Limitations: Weather conditions can damage notes or equipment, and lost materials can hinder analysis.
Measurement:
This method is useful when you need to quantify specific aspects of your environment.
Advantages: Provides precise and objective data for analysis, and allows for comparison with existing data sets.
Limitations: Requires proper use of tools (which may be limited in availability), accuracy can be affected by tool malfunction or user error.
Sampling:
Since it's often impractical to study an entire population, sampling allows you to collect data from a representative subset.
Advantages: Saves time and resources, and allows for detailed investigation of a smaller group.
Limitations: Incomplete data can lead to inaccurate conclusions if the sample isn't truly representative.
Sketch Map Drawing:
Creating a sketch map is a visual way to document the spatial relationships between different features in your study area.
Advantages: Helps visualize the layout and connections between geographical elements, and provides a clear reference point for your observations.
Limitations: Whilst it can increase your final grade, accurate sketching requires skill and time.
Presenting Your Findings
Once you've collected your data, it's time to showcase your findings! Here are two key aspects to consider:
Geographical Significance:
Explain how your fieldwork results contribute to the broader understanding of geography. This might involve:
Relating your findings to existing geographical knowledge about the area.
Highlighting the relationships between physical and human aspects of the environment.
Problems Encountered:
Be honest about any challenges you faced during data collection. Explain how these problems may have affected your results and what you might do differently next time.
Follow-up Activities
Fieldwork doesn't end with data collection. Here are some essential follow-up steps:
Data Analysis: This is where you make sense of your data. Organize, sort, and interpret the information you gathered. Look for patterns, trends, and connections between different data points.
Refine Fieldwork Materials: Finalize any sketches, maps, or tables you created during data collection. Ensure they are clear, well-labeled, and ready for inclusion in your report.
Compare Information: If you worked in a group, compare your findings and combine data for a more comprehensive picture. Discuss any discrepancies and work towards a cohesive analysis.
Report Writing: Compile your findings into a final report that follows the required format. This typically includes an introduction, methodology, results, discussion, and conclusion sections.
Ethical Considerations:
Respect for the Environment: Minimize your impact on the study area. Avoid damaging vegetation, disturbing wildlife, or littering.
Respect for People: If interviewing people, obtain informed consent and ensure anonymity if promised. Be courteous and respectful of their time and privacy.
Safety:
Plan Ahead: Conduct a risk assessment of your study area and identify any potential hazards.
Work with a Partner: Never go on fieldwork alone, especially in unfamiliar areas.
Inform Others: Let someone know where you're going, what you'll be doing, and when you expect to return.
Be Prepared: Dress appropriately for the weather and terrain. Bring necessary supplies like water, sunscreen, insect repellent, and a first-aid kit.
Technology:
While traditional methods like pen and paper are still valuable, consider using technology to enhance your fieldwork:
GPS Devices: Track your location and record waypoints for creating accurate maps.
Digital Cameras: Capture high-quality photos and videos to document your observations.
Data Collection Apps: Use specialized apps to record observations, conduct surveys, or collect measurements.
IB Geography- Ultimate Study Guide
Patterns and Change
This is the core theme for DP Geography and it helps to provide a foundation for exploring key global issues. It encompasses four key units:
Populations in transition
Disparities in wealth and development
Patterns in environmental quality and sustainability
Patterns in resource consumption
Populations in Transition
Population Trends:
Global population change 1930-2020
In most regions, population growth has increased between 1930 and 1960, and then again between 1960 and 1990 (Africa, South America, Australia, Asia) except North America and Europe.
In contrast, the projected changes for 1990-2020 show that the population growth rate will fall all over the globe
Exponential growth
Increasing/accelerating growth rate
The world’s population is growing rapidly, most of it being recent
Global pop. Doubled between 1650 and 1850, 1850 and 1920, and 1920 and 1970 (taking less and less time to double)
Up to 95% of pop. growth is taking place in LDC
This trend of growth is defined as exponential growth
Despite this, world population is expected to stabilize at about 12 billion by around 2050-80
This growth creates:
Pressures on the government to provide for their people
Environmental pressure
Increased risk of disease and malnutrition
Greater differences between poor and rich countries
Demographic change and global trends
The annual growth rate is found by subtracting the crude death rate (% of deaths per thousand people, also referred to by number of deaths per thousand) from the crude birth rate (% of births per thousand people, also referred to by the number of births per thousand) and is then expressed as a percentage
The highest growth rates are found in Africa, and lowest in North America and Europe
Birth Rates:
Measurements of fertility
Crude birth rate (CBR) = total number of births/total population x 1000 per year (doesn’t consider age and sex structure of population), total number of births per thousand.
Standardized birth rate (SBR) in contrast to the CBR, gives a birth rate for a region based on the premise that the region’s age composition is the same as that of the whole country.
Total fertility rate (TFR) is the average number of births per woman.
The general fertility rate is the number of live births per 1000 women of reproductive age in a country
GFR = number of live births/number of women in reproductive age x 1000 per year
The age-specific birth rate (ASBR) = number of births/women of any specified age x 1000 per year
In general, the highest fertility rates are shown in LEDCs (Less economically developed countries) and the lowest in MEDCs (More economically developed countries), with the TFR in MEDCs being an average of 1.7, and in LEDCs an average of 5.8.
Changes in fertility
Changes are a result of a combination of sociocultural and economic factors
Sociocultural factors and fertility
Status of women
The status of women is assessed by the gender-related development index (GDI), which measures the inequality between the sexes in life expectancy, education and the standard of living.
In countries where the status of women is low and few women are educated or involved in paid employment, birth rates are generally higher
An example is Singapore, where the status of women has improved, and from 1960 to 2000, because of this improvement, the rate fell from 3.0 to 1.5
Level of education and material ambition
In general, the higher the level of parental education, the fewer the children
Middle-income families with high aspirations but limited means tend to have smaller families
To improve standards of living, they limit family size
An example is Ethiopia (2005) where uneducated women had TFR’s of 6.1 and educated ones with a TFR of (2.0)
Type of residence
People in rural areas have more children than in urban
This is because:
More rigid social pressures on women
Greater freedom and less state control in rural areas (e.g. China’s one-child policy is enforced less rigorously in rural areas)
Females in rural areas have fewer educational and economic opportunities
In some urban areas, such as shanty towns, there are high levels of fertility because of their youthful population structure
Religion
In general, most religions are pro-natalist and favor larger families (are against abortions, sterilization, etc.)
The health of the mother
Sometimes, women who are unhealthy and have some miscarriages become pregnant more often to compensate
Economic factors and fertility
Economic Prosperity
Not complete correlation, but there are some links
Economic prosperity favours an increase in the birth rate while increasing costs lead to a decline in the birth rate
The UN believe that a reduction in the high birth rates in the LEDCs can be achieved only by improving the standards of living in those countries
In addition, equitable distribution of wealth tends to lower the fertility rate
Canada has a higher level of GNP per capita (US$) than Tanzania (20,000 to 200) and therefore has a lower TFR (1.6 in comparison to 5.5)
The need for children
High infant mortality rates increase the pressure on women to have more children (replacement/compensatory births)
Larger families in agricultural societies help provide labour for the farm
Mortality:
Measurements of mortality
The crude death rate (CDR) = total no. of deaths/total population x 1000 per year(number of deaths per 1000 per year)
Poor measurement of mortality (doesn’t consider many other factors, Pakistan’s crude rate of 7.8% is less than that of Denmark’s 11%
Better measures are the standardized mortality rate (SMR), and age-specific mortality rates (ASMRs) such as the infant mortality rate (IMR)
IMR = total no. of deaths of children <1 year old/total no. of live births per year x 1000
The child mortality rate (CMR) = total no. of deaths of children aged 1-5 years/total number of children aged 1-5 years x 1000
Life expectancy (E0) is the average number of years that a person can be expected to live, given the demographic factors are constant
Patterns of mortality
Patterns of mortality differ from MEDCs to LEDCs
In MEDCs, the death rate falls steadily to 9% with high life expectancies (75+)
In LEDCs, the opposite can be seen, but due to steady improvements over the past few decades in the food supply, water, sanitation and housing, the situation is improving
However, this trend has unfortunately been reversing as a consequence of AIDS
Population Pyramids:
Population pyramids tell us a great deal of information about the age and sex structure of a population:
A wide base suggests a high birth rate
A narrowing basis suggests a falling birth rates
Straight or near-vertical sides show a low death rate
A concave lope suggests a high death rate
Bulges in the slope indicate high rates of immigrant
Deficits in the slope show out-migration or age-specific or sex-specific deaths
Population pyramids can also be used to show the racial composition of a population or the employed population group
Pop. Pyramids are important because they tell us about population growth.
They help planners to find out how many services and facilities, such as schools and hospitals will be needed in the future
Demographic transition model:
4 stages
Stage 1: Pre-transition
High BR
High infant mortality rates
High DR
High fertility
Many young, few old
Upwards curving population pyramid
Stage 2: Early-transition
DR declines rapidly (better medical care)
BR + FR remain high
Many you people
Infant mortality declines
Triangle shape population pyramid
Stage 3: Late-transition
BR declines rapidly
DR declines slowly
FR declines
Increasing older people
Rounded triangular shape
Stage 4: Post-transition
Low BR + DR
Fertility rate around 2.1 (replacement rate)
Greying society
Stable/slow pop growth
Bullet-shaped population pyramid
Gender and Change:
Gender and population growth
High rates of population growth are associated with a low status of women in society
The UN Decade for Women, from 1975 to 1985 recommended three important points for action:
There should be legal equality for women
Further development needs to improve on the substandard role that women play
Women should receive an equal share of power
Gender and social role
In 1970, Esther Boserup identified women as having been left behind in the development process
The social roles that women have are mostly
Biological reproduction
Social reproduction
Economic reproduction
These three roles create a great deal of physical and psychological stress
It is believed in sub-Saharan Africa that:
Up to one-third of women are pregnant or breastfeeding at any one time
Women comprise over half the workforce, sometimes 70%
Women grow over 80% of the food eaten and contribute half of the region’s cash crops
Women and development
Strategic or political change is needed to attain equality and empowerment
Progress for sexual equality has been painfully slow
For example, the illiteracy rate is much higher for girls than boys, and generally, women are becoming poorer (supposedly)
Gender inequalities in adult literacy are higher in African and Arab cities
The reasons for slow progress
Conditions are deteriorating in a large part of Africa
As a result of structural adjustment programmes (SAPs), countries spend less money on health and social welfare (disproportionately borne by women)
There is a lack of commitment to women by man countries and by donors
Women have to work as well as be the head of the household, but they have little legal status
Responses to high and low fertility:
Political factors and family planning
Most governments in LEDCs have introduced programmes aimed at reducing birth rates
Effectiveness depends on:
Focusing on family planning and not just birth control
Investing sufficient finance in the schemes
Working in consultation with the local population
Where birth controls have been imposed by the government, less successful (except China)
In MEDCs, financial and social support for children is often available to encourage a pro-natalist approach
However, where fears of negative pop. Growth (Singapore), more direct measures taken to increase birth rates
Dependency ratios
The dependency ratio measures the working population and the dependent population
Population aged <15 + population aged >60 (dependents)/Population aged 16-59 (economically active)
In the developed world, there is a high proportion of the elderly
In the developing world, there is a higher proportion of youth
Aging ratios
The future trend in the old-age dependency ratio for the EU countries is increasing
Currently for working individuals for each person 65 or older
Will drop down to two, or worse, generally due to the low birth rates
Migration:
Types of movement
Migration is the movement of people, involving a permanent (more than one year)change of residence
Internal or external (international), voluntary or forced
Patterns of migration according to Ravenstein
Most migrants proceed over a short distance
Due to limited technology and transport, (poor communications), people know more about local opportunities
Migration occurs in steps
Typically from rural to small town, to large town to city (people become “locked in” to the urban hierarchy)
As well as movement to large cities, movement away (dispersal)
The rich move away and commute from nearby villages and small towns
Urban dwellers migrate less than rural dwellers
Fewer opportunities in rural areas
Women are more migratory than men over short distances
Especially for marriage and in societies where the status of women is low
Migration increases with advances in technology
Transport, communications, spread of info
Migration according to Lee (1966)
Described migration in terms of push and pull factors
Push factors are negative features causing a person to move away from a place(unemployment, natural hazards etc.)
Pull factors are the attractions (better wages, schools etc.)
Limitations of models
Models have many assumptions
Are all people free to migrate?
Do all people have skills, education etc. allowing them to move
Are there barriers to migration
Is distance a barrier to migration
Migration:
Origin of disparities:
Inequalities in development
Despite considerable economic growth in many regions, the world is more unequal than it was 10 years ago
Some countries left behind in the “poverty cycle”, aren’t able to develop as fast as others
Even within the group of countries that are commonly thought of as poor, there is variation in levels of poorness
For example, both Taiwan and South Korea have extremely high levels of GNI per capita
Employment
The gulf between formal and informal economies
Widening gap between skilled and unskilled labour
Growing disparities in health, education and opportunities for social, economic and political participation
Inequalities between and within countries have accompanied globalization
These have had many negative consequences in many areas, including employment, job security and wages
Unemployment remains high, especially youth unemployment
Youths are two to three times more likely than adults to be unemployed and currently make up as much as 47% of the total 186 million people out of work worldwide (most labor markets unable to absorb them)
Millions are working but remain poor (don’t reach the poverty threshold of 1$ a day)
A large majority of the working poor are informal agricultural workers (globalization led to an explosion of the informal economy)
In many countries, wage inequalities (esp. between skilled and unskilled workers)
Falling real minimum wages and sharp rises in the highest incomes
Rich countries with income gap, such as Canada, UK and USA
Parental education and inequality
Link between investment in education and poverty is extremely fundamental
Education may raise incomes of those with it (and those with higher qualifications tend to have less children)
Global disparities and change:
Changing global inequalities
PPP: what a person can by with their income at local prices
Until 200 years ago, Asia was the dominant world economic power
Today rapid econ. growth rates are helping the region regain its former position
Used to be Asia dominant, with Europe and Africa in 2nd and 3rd around the year 100
Currently, Asia is almost dominant, with Australia, Canada, New Zealand and the US combined in second, then after that Europe, Latin America, Japan, Africa and USSR
Income Inequalities (“Twin Peaks” of rich and poor)
The greatest contributors to income inequality are the largest countries at either end of the spectrum, the “Twin Peaks”
One pole represents the 2.4 billion people whose mean income is less than $1000 a year and includes people living in India, Indonesia and rural China. With 42% of the world’s population, this group receives just 9% of the world’s PPP incomes
The other pole reps 500 million people whose annual income exceeds $11500
Group includes USA, Japan, Germany, France and the UK
Combined, account for 13% of the world’s population but use 45% of the world PPP income
In the last 25 years, the main changes in come between diff. regions of the world include:
The continued rapid econ. growth in the already rich country relative to most of the rest of the world
The decline in real income of sub-Saharan Africa and eastern Europe
Relatively modest gains in Latin American and Arab states
Some most important global disparities relate to lack of decent work and low incomes
According to ILO (international labour organization), about 200 million people don’t have any form of work
Social inequalities
Despite some progress, health and education inequalities have widened, especially within countries
Sub-Saharan Africa and parts of Asia are in the worst predicament
Wide gaps in access to immunization, maternal and childcare, nutrition and education
Gender gaps in access to education have narrowed somewhat, but persist
Indigenous people, persons with disabilities, older people and youth are typically excluded from decision-making processes that affect their welfare
Environmental impacts
Today’s disparities are also closely linked to human impact on environment
Poor frequently end up with poor land, water, fuel and other natural resources (limit productivity)
Patterns in environmental quality and sustainability
Atmosphere and Change:
Global warming
Refers to the increase in temperatures around the world that has been noticed over the last 50 years or so, and in particular since the 1980`s
Greenhouse effect is the process by which certain gases (water vapour, CO2, methane etc.) allow short-wave radiation from the sun to pass through to heat up the earth, but trap an increasing proportion of long-wave radiation from the earth
Enhanced greenhouse effect is increased amount of greenhouse gases in the atmosphere due to human activities
CO2 levels have risen from about 315 ppm in 1950 to 355 ppm and are expected to reach 600 ppm by 2050
Caused by burning of fossil fuels, deforestation (also removes trees that convert the CO2 to oxygen)
Methane is the second largest contributor to global warming (increasing rate of 1% per annum)
Cattle convert 10% food they eat into methane, emit 100 million tonnes of methane each year
Natural wetlands and paddy fields also emit 150 million tonnes annually
CFCs are synthetic chemicals that destroy ozone and absorb long wave radiation from the earth
Increasing at rate of 6% per annum, and are up to 10000 times more efficient at trapping heat than CO2
Effects of global warming
A rise in sea levels caused flooding in low-lying areas such as the Netherlands, Egypt and Bangladesh (over 200 million could be displaced)
Increase in storm activity
Changes in agricultural patterns (decline in the US grain belt, increase in Canada`s growing season)
Reduced rainfall over the USA, southern Europe
Extinction of up to 50% of species of wildlife
Implications of climate change
Global warming
Climate change
Extreme events
Long term change
Temperature, wind, pressure, precipitation, humidity
Storms, drought, fire, erosion, landslides, sedimentation, avalanches, pests and diseases
Sea level rise
Coastal erosion, flooding, salination
River flooding, bank erosion,
Waves, Tsunami
Policies to combat climate change
Emission of main anthropogenic (man-made) GHG, CO2, influenced by size of the human population, amount of energy used per person, level of emissions resulting from that use of energy
A variety of options which could reduce emissions, especially from the use of energy, are available
Reducing CO2 emissions can be done through:
Improved energy efficiency
Fuel switching
Use of renewable energy sources
Nuclear power
Capture and storage of CO2
Another measure involves increasing the rate at which natural sinks take up CO2 (i.e. increase the number of forests)
Water usage and change:
Changing supply and demand
Use of water has increased six time in past century, world population tripled
Some rivers that formerly reached the sea no longer do so, diverted for our use (example of Colorado in the USA)
Half world’s wetland disappeared, today 20% of freshwater species are endangered or extinct
Many aquifers are being depleted, and water tables in many parts of the world are dropping at an alarming rate
World water use is projected to increase by about 50% in next 30 years
Estimated by 2025, 4 billion people will live under conditions of sever water stress (conditions particularly severe in Africa, Middle East and south Asia)
May fuel armed conflicts
Currently estimated 1.1 billion people lack access to safe water, 2.6 billion without adequate sanitation, and more than 4 billion do not have their waste water treated to any degree
Water supply
Depends on several factors in the water cycle, including rates of rainfall, evaporation, use of water by plants (transpiration), river and groundwater flows
Less than 1% of freshwater available is available for people to use (everything else locking in ice sheets and glaciers)
Globally, 12500 km3 of water are considered available for human use on an annual basis
About 6600 m3 per person per year
Only 4800 m3 likely per person in 2025
Freshwater is not evenly distributed around the world
Three-quarters of rainfall occurs in areas containing less than one-third of the world's population (whereas two-thirds of the world's population live in areas receiving only one-quarter of the world`s annual rainfall)
20% of global average runoff each year is accounted for by the Amazon Basin, a vast region with fewer than 10 million people
India gets 90% of its rainfall during the summer monsoon season (other times rainfall is extremely low)
Water stress
When per capita water supply is less than 1700 m3 per year, an area suffers from ``water stress”, and is subject to frequent water shortages
In many areas, less than 1000 m3 per capita, causing problems for food production and economic development
2.3 billion people live in water-stressed areas
Water stress will affect 3.5 billion people (48% of world pop.) projected by 2025
Water use
Currently, quantity of water used for all purposes exceeds 3700 km3 per year
Agriculture is largest consumer (two-thirds of all water from rivers, lakes and groundwater
1960, water used for crop irrigation risen by 60-70%
Industry uses about 20% of available water, and municipal uses about 10%
Pop. growth, urbanization and industrialization have increased the use of water in these sectors
As world pop. and industrial output have increased, by 2025 global availability of freshwater expected to drop 25% from year 2000 figure to 5100m3
Water scarcity
Two types of water scarcity affect LEDCs in particular:
Physical water scarcity
Occurs where water consumption exceed 60% of the usable supply
To help meet water needs, countries such as Saudi Arabia and Kuwait import much of their food and invest in desalinization plants
Economic water scarcity
Country physically has sufficient water, but additional storage and transport facilities needed (embarking on expensive water development projects, of too high a cost)
In addition, in LEDCs access to adequate water supplies is most affected by exhaustion of traditional sources such as wells and seasonal rivers
In many poor countries farmers use, on average, twice as much water per hectare as industrialized countries, but their yields are three times as low (six times difference in efficiency of irrigation)
Water quality
Needs to be of adequate quality for consumption
WHO estimates 4 million deaths each year attributed to water-related diseases (cholera, hepatitis, malaria and other parasitic diseases)
Real problem of drinking water and sanitation in developing countries is too many people lack access to safe and affordable water supplies and sanitation
Global water supply and sanitation
Urban areas are better served than rural ones, and countries in Asia, Latin America and the Caribbean are better off than African countries
Many piped water systems however do not meet water quality criteria, leading more people to rely on bottled water (as in major cities in Columbia, India, Mexico, Thailand, Venezuela and Yemen)
Some cases, poor pay more than rich for water
Port-au-Prince, Haiti, survey have shown households connected to water system typically paid around $1.00 per cubic metre, while unconnected customers forced to purchase water from mobile vendors paid from $5.50 to $16.50 per cubic metre
Sanitation and population growth
Fewer people have adequate sanitation than safe water, and global provision of sanitation is not keeping up with pop. growth
Between 1990 and 2000 number of people without adequate sanitation rose from 2.6 billion to 3.3 billion
Least access to sanitation occurs in Asia (48%), especially in rural areas
Still pressure points, especially in areas of rapid pop. growth
Squatter settlements in many of world’s poorest cities, local authorities unable to or legally prevented from providing sanitation, situation is likely to deteriorate rapidly
Patterns in resource consumption
Ecological Footprints:
Calculating ecological footprint
Everything used for our daily needs comes from natural resources
Ecological footprint measured in acres or hectares, calculates amount of earth`s bio productive space needed to keep a population at its current level of resource consumption
Calculation takes into account:
Arable land:
Amount of land required for growing crops
Pasture land:
Resources required for growing animals for all forms of consumption
Forests:
For fuel, furniture etc., also providing many ecosystem services such as climate stability, erosion prevention
Oceans:
For marine products
Infrastructure needs:
Based on built-up land used for these needs
Energy costs:
Land required for absorbing carbon dioxide emissions and other energy wastes
Ecological footprint, global and national
Planet`s biological productive capacity (biocapacity)is estimated at 1.9 ha per person
Currently, countries are using up to 2.2 ha per person, beyond the planet`s biocapacity to sustain us by 15%
The deficit is showing up as failing natural ecosystems – forests, oceans, soil, water etc.
Planet`s biocapacity is affected by global population as well as rate of consumption
Increased consumption depletes the planet’s carrying, renewal and regeneration capacities
The ecological footprint estimated available to each person would be reduced to 1.5 by 2050
If we continue at the consumption rates of the rich Western countries, we will need 4 to 5 earths to sustain ourselves
The USA is a country with the largest per capita footprint in the world – 9.57
If everyone lived like Americans, Earth could only support 1.2 billion people, but if everyone was like those in Bangladesh, it could support 22 billion people (footprint of 0.5 ha)
Global ecological footprint grew from about 70% of capacity in 1961 to 120% in 1999
The future projections show growth of about 180 to 220% by 2050
Environmental Sustainability:
Environment sustainability index
ESI was produced by a team of environmental experts at Yale and Columbia
Using 21 indicators and 76 measurements including natural resource endowments, past and present pollution levels, and policy efforts, the report creates a “sustainability score” for each country, with higher scores indicating better environmental sustainability
10 most sustainable countries as ranked by the ESI are dominated by wealthy, sparsely populated nations with an abundance of natural resources
Finland ranks first, with Norway, Sweden and Iceland all in the top 5
The only developing nations in the top 10 are Uruguay and Guyana, which have relatively low pop. densities and an abundance of natural resources
Conversely, the only densely populated countries that have received above-average rankings are Japan, Germany, the Netherlands and Italy, some of the richest countries on the list
Environmental sustainability is essential in aiding the poor
Highly dependent on the environment and its resources which provide roughly two-thirds of household income for the rural poor
Climate change is dramatically reshaping the environment on which poor people depend
Climate change increases rainfall variability (droughts and floods), food security, spread of disease, increased risk of accidents and damage to infrastructure
Poor are most vulnerable to these changes and have limited capability to respond to them
Overfishing has led to the collapse of many fisheries, and one-quarter of global marine fish stocks are currently overexploited or significantly depleted
About 60% of the ecosystem services resources evaluated by the UN’s Millennium Ecosystem Assessment (a measure of how ecosystems benefit people), are being degraded or are being used unsustainably
Between 10% and 30% of mammal, bird and amphibian species face extinction
Global timber production has increased by 60% in the past four decades, meaning roughly 40% of forest area has been lost, and deforestation continues at a rate of 13 million ha per annum
Challenges and solutions
Environmental concerns are fundamental to long-term sustainable development
Efforts must be made to improve understanding of the environmental impact of development strategies and to recognize the link between environmental degradation and poverty
The poor, who are most dependent on natural resources and are most affected by environmental degradation, lack the information or access to participate in decision-making and policy development
In contrast, those who influence policy development have little understanding of the costs and benefits associated with environmental policy
Economic growth and the environment are often still viewed as competing objectives
But investing in environmental management can be cost-effective, and it contributes to improving livelihoods
Managing the Korup National Park
Created in 1986 by the government of Cameroon with the support of the WWF
Under the law, human activity in the park is limited to tourism, research and recreation
The project aims to integrate the National Park into the local economy and regional development plans
An example of sustainable development in Korup is that of community forests
These are large areas of forest in which villagers obtain and manage a part of the communal forest sustainably (reviewed regularly by the government and WWF)
Management of Korup is important, contains over 400 species of trees, 425 species of birds, 120 species of fish and 100 mammal species
Over 60 species occur only in Korup, and 170 are considered to be endangered or vulnerable
The changing importance of alternative energy sources:
Renewable resources
Include hydroelectric power, solar, wind and tidal
World potential renewable energy
Wind Energy is the smallest, mostly in North America, Northern Europe, Japan Australia and New Zealand, South America, China, India
Biomass biggest, mostly in South America, North America, the Former Soviet Union and Eastern Europe, Southern Africa, Northern Europe
Hydroelectricity second largest, mostly in North America, South America, Northern Europe, the Former Soviet Union and Eastern Europe
Solar energy is lowest with similar countries possessing the potential to use it
Trends in renewable energy sources
Renewable energy is growing fast
Rates of development of renewable energy sources are far exceeding those of fossil fuels such as oil, coal and natural gas
2006, wind and solar development grew by 20% and 40% respectively
The market for renewable energy sources was about $55 billion worldwide in 2006, with forecasted growth to $226 billion by 2016
Conservation, waste reduction, recycling and substitution:
Recycling
refers to the processing of industrial and household wastes (such as paper, glass and some metals and plastics) so that materials can be reused
Saves scare raw materials and helps reduce pollution
UK fallen behind other EU countries with recycling because there are more landfill sites which are cheaper to use (has recycling target of 33% by 2015)
Reuse
Refers to multiple use of a product by returning it to the manufacturer or processor each time (more energy and resource efficient than recycling)
Reduction
Using less energy, such as turning lights off when you don’t need them
Substitution
Using one resource rather than another (renewable verse non-renewable)
Landfill
Burying of waste in the ground, and then covering over the filled pit with soil and other material
Cheap but not always healthy (mostly domestic waste, some hazardous waste allowed as well)
Fly-tipping
When people/companies dump waste/old equipment
Increasing problem
Done because of increased costs of landfills
Also more goods, such as TVs, computers and refrigerators classified as hazardous and subject to restrictions on how they are disposed of
Introduction of strict new EU regulations means high proportion of new products must be recycled (costly to manufacturers and purchasers)
The Freshwater System
The Hydrological Cycle
Key Terms
Precipitation: the transfer of moisture (rain, snow etc) to the earth's surface from the atmosphere.
Interception: the capture of raindrops by plant cover, which prevents direct contact with the soil.
Runoff: precipitation that does not soak into the ground but flows over it into surface waters.
Groundwater: water held underground in soil or porous rock, often feeding springs and wells.
Evapotranspiration (EVT): the loss of water from vegetation and water surfaces to the atmosphere.
Potential evapotranspiration (pEVT): the rate of water loss from an area if there were no shortages of water
Maximum sustainable yields (MSY): the maximum level of extraction of water that can be maintained indefinitely for a region.
The hydrological cycle, also known as the water cycle, is the continuous movement of water on, above, and below the surface of the Earth.
It's a complex system with various interconnected processes responsible for distributing freshwater globally.
The water cycle involves the exchange of energy, which leads to temperature changes.
For instance, when water evaporates, it takes up energy from its surroundings and cools the environment.
When it condenses, it releases energy and warms the environment.
These heat exchanges influence climate.
The evaporative phase of the cycle purifies water which then replenishes the land with freshwater.
The flow of liquid water and ice transports minerals across the globe.
It is also involved in reshaping the geological features of the Earth, through processes including erosion and sedimentation.
The hydrological cycle is a closed system because water can not be added or lost.
Although water can not be added or lost it can be found in different states and in different locations.
Despite the planet being covered in water, the vast majority is sea water (97.5%). Of the remaining 2.5% the majority is held in glaciers and ice sheets.
Only a very small amount of the world’s water is easily accessible in rivers and lakes (0.00069%)
Closed System:
In a closed system, there is no exchange of matter with the surroundings, only energy.
Hydrological Cycle as a Closed System:
When considering only the movement of water molecules within the Earth's system, it can be simplified as a closed system.
The total amount of water on Earth remains constant, although it continuously changes states and locations through the various processes of the cycle.
Open System:
In an open system, both matter and energy can be exchanged with the surroundings.
Hydrological Cycle as an Open System:
When considering the energy transfers involved in the water cycle, it's clearly an open system.
Solar energy from the sun drives the entire cycle, causing water to evaporate and eventually return as precipitation.
Additionally, a small amount of water vapor escapes Earth's atmosphere, entering the open space, making it a truly open system in that sense.
Precipitation:
This is the initial stage where water vapor in the atmosphere condenses and falls back to Earth as rain, snow, sleet, or hail.
Factors like temperature, pressure, and wind currents influence precipitation patterns, leading to uneven distribution across the globe.
Types of precipitation:
Convectional precipitation: Occurs due to rising warm air, common in tropical regions.
Orographic precipitation: Forced uplift of air over mountains, leading to rain on windward slopes.
Frontal precipitation: Warm and cold air fronts colliding, resulting in widespread precipitation.
Interception:
Before reaching the ground, precipitation encounters various surfaces like leaves, branches, and vegetation.
Some water gets trapped or evaporates directly back into the atmosphere.
Factors affecting interception:
Type and density of vegetation
Leaf surface area
Rainfall intensity and duration
Infiltration:
Water that doesn't evaporate penetrates the ground surface, entering the soil zone. Soil texture, porosity, and moisture content determine the infiltration rate.
Infiltration pathways:
Macropores: Large channels allowing rapid infiltration (e.g., cracks, wormholes)
Micropores: Smaller spaces facilitating slower infiltration
Infiltration impacts:
Replenishes soil moisture crucial for plant growth
Contributes to groundwater recharge
Runoff:
Water that doesn't infiltrate either evaporates or flows over the land surface as runoff.
Types of runoff:
Overland flow: Water sheet flow directly over the land
Channel flow: Water concentrated in streams and rivers
Subsurface flow: Water infiltrating shallow soil layers and moving laterally towards waterways
Runoff factors:
Rainfall intensity and duration
Slope and topography
Soil permeability and saturation
Land cover (e.g., vegetation, urbanization)
Evapotranspiration:
This combined process involves the evaporation of water directly from soil and water bodies and the transpiration of water vapor from plants through their leaves.
Types of evapotranspiration:
Evaporation: Direct change of liquid water to vapor from surfaces
Transpiration: Release of water vapor from plant stomata during photosynthesis
Evapotranspiration impacts:
Returns water vapor to the atmosphere for further precipitation
Regulates surface temperature and humidity
Influences plant growth and ecosystem health
Groundwater Recharge:
A portion of infiltrated water percolates deeper into the soil, eventually reaching the saturated zone below, replenishing groundwater aquifers.
Factors affecting recharge:
Soil permeability and depth
Groundwater table depth
Rainfall patterns and intensity
The Water Balance
The water balance basically looks at the balance between inputs and outputs.
You can look at the water balance at a global level (hydrological cycle), at a local level (drainage basin cycle) or even just a field.
At a global level oceans tend to experience greater outputs (evaporation) than inputs (precipitation).
This is because oceans are large areas with no shade that have regular winds blowing saturated air on land, allowing greater evaporation.
In addition oceans don’t tend to suffer from the same amount of relief and convectional rainfall as land does.
On land, inputs (precipitation) tends to be greater than outputs (evaporation).
This is because lands suffers from larger amounts of frontal, relief and convectional rainfall, as well as much of the lands water being protected underground or in shaded areas reducing evaporation.
At a global level there obviously has to be an equilibrium between inputs and outputs.
The excess precipitation on land is returned to the oceans by channel flow, surface run-off and to a lesser extent groundwater flow.
The excess of evaporation is returned to the land from the sea by winds blowing saturated air on land.
Drainage Basins and Flooding
Key Terms
Drainage basin: the area drained by a river and its tributaries
Water balance: the relationship between the inputs and outputs of a drainage basin
Soil moisture excess: when soil moisture and groundwater is replenished. The excess may lead to saturation and increased surface run-off
Drainage divide or watershed: the line defining the boundary of a river or stream drainage basin separating it from adjacent basins
Discharge: the volume of water passing a given point over a set time
Peak rainfall: The highest rainfall (usually measured in mm) during a storm.
Drainage Basin
Inputs:
The main input to the system is precipitation.
The type of precipitation (rain or snow, etc), the intensity, the duration and frequency all have an effect on the amount of water in the system.
Each subsystem of the drainage basin system will also have inputs and ouputs, and the output from one stage of the diagram will form the input for another.
Precipitation: Any moisture that falls from the atmosphere.
The main types of precipitation are rain, snow, sleet, hail, fog and dew.
Inter-basin transfer: Water that either naturally (due to the alignment of the rock) or with human involvement (pumps and pipes) moves from one drainage basin to another.
Transfer:
The sum of all the water flowing over the drainage basin’s surface is called runoff.
It is made up of streamflow, which is flow through permanent river channels and overland flow or surface runoff.
Overland flow transfers water through the basin either as sheetwash, across the surface, or in tiny channels called rills.
Beneath the surface, water is transferred via throughflow, which is the movement of water through the lower soil towards rivers, and groundwater flow.
Groundwater flow is typically very slow.
Water that has been intercepted by foliage may also be transferred, either directly as throughfall, or by running down branches and stems via stemflow.
Stem flow: When intercepted water runs down the trunks and stems of vegetation.
Canopy drip: When intercepted water drips off the leaves of vegetation (drip tip leaves in rainforests are actually designed to allow this to happen).
Throughfall: Precipitation that falls directly through vegetation.
Infiltration: Water that moves from the surface of the earth into the soil below.
Throughflow: Water that travels through unsaturated ground.
Pipeflow: Water that travels through holes left by root systems and animals burrows.
Percolation: Water that travels from unsaturated into saturated ground.
Groundwater flow (baseflow): Water that travels through saturated ground.
Capillary action (or rise): Water that may move upwards towards the surface.
Channel flow: Water that travels in a river.
Surface run-off (overland flow): When water travels across the surface of the earth e.g. down a hill.
Storage
Water is stored in a drainage basin on the surface in lakes and channels or underground in the groundwater store.
Water reaches the groundwater store via the processes of infiltration and percolation.
During these processes, some water will be stored in the soil and rock.
The amount of water stored will vary depending on the porosity of the soil and on the permeability of the rock.
Water can also be temporarily stored via interception.
This refers to the storage of water on leaf and plant stems.
Dense foliage may result in little water reaching the ground, since it often evaporates from the leaves.
Interception: When water is caught and held by vegetation or man-made structures like buildings.
Surface store: When water is held in the surface of the earth.
This may be a puddle, a lake or a garden pond.
Soil moisture store: When water is held in unsaturated soil.
Groundwater store: When water is held in saturated ground.
Outputs
The final release of the water in a drainage basin is known as its output.
Typically, rivers flowing into the sea will be the main output of a drainage basin. Some water will also be lost via evapotranspiration.
This process refers to direct evaporation, and also to the extend that moisture lost from leaves will result in plants withdrawing water from the soil via their roots.
Evaporation: The process of water turning from a liquid into a vapour. Evaporation only takes place from a body of water e.g. a lake, puddle or the sea.
Transpiration: The evaporation of water from vegetation.
Evapotranspiration: The combined action of evaporation and transpiration
Inter-basin transfer: Water that either naturally (due to the alignment of the rock) or with human involvement (pumps and pipes) moves from one drainage basin to another.
River discharge via channel flow: Water entering the sea and leaving a drainage basin.
A very small amount of water also enters the sea via throughflow and groundwater flow (baseflow).
River Profile
Split into upper course, middle course, and lower course
As river flows, it is shaped by erosion, transportation, and deposition
Erosion
River erosion is the wearing away of the land as the water flows past the bed and banks.
There are four main types of river erosion:
Attrition: occurs as rocks bang against each other gradually breaking each other down (rocks become smaller and less angular as attrition occurs)
Abrasion: this is the scraping away of the bed and banks by material transported by the river
Solution: chemicals in the river dissolve minerals in the rocks in the bed and bank, carrying them away in solution.
Hydraulic Action: this is where the water in the river compresses air in cracks in the bed and banks.
This results in increased pressure caused by the compression of air, mini 'explosions' are caused as the pressure is then released gradually forcing apart parts of the bed and banks.
Transport
Material may be transported by a river in four main ways: solution; suspension; saltation and traction.
The type of transport taking place depends on the size of the sediment and the amount of energy that is available to undertake the transport.
The chemical composition of the parent rock from which sediments originate.
In the upper course of the river there is more traction and saltation going on due to the large size of the bed-load, as a river enters its middle and lower course there is a lot of finer material eroded from further upstream which will be carried in suspension.
Deposition
Where material carried by the river is dropped and occurs when there is no longer sufficient energy to transport material.
May result in the formation of features such as slip off slopes (on the inner bends of meanders); levees (raised banks) alluvial fans; meanders; braided streams and the floodplain.
Eroded material carried in suspension and solution will be dropped last.
Discharge
Discharge is the volume rate of water flow (velocity), which is transported through a given cross-sectional area. Discharge is normally measured in cumecs (cubic metres a second).
Discharge = cross section of channel (m2) x velocity of water (m/s)
Bed: The bottom of the river channel
Banks: The sides of the river channel.
Channel: The confines of the river, encompassing the bed and two banks.
Wetted Perimeter: The total length of the bed and the banks in contact with the river.
Cross-sectional area: The width of the river multiplied by the depth of the river.
Because the depth of the river will vary across its width, an average depth reading is normally taken. The cross sectional area is normally given in m2.
Velocity: This is the speed that the water in a river is travelling at. The unit of measurement is normally meters a second (m/s). River velocity can be measured using a flowmeter
Channel roughness – as large angular boulders create a rough channel shape and therefore, a large amount of its bed friction.
This creates more resistance to flow than a river with smooth clays and silt forming its banks.
The roughness coefficient is measured using Manning’s ‘n’, which shows the relationship between channel roughness and velocity.
Regimes - variations in a river flow
The regime of a river is expected to have a seasonal pattern of discharge during the year.
This is due to factors such as climate, local geology and human interaction.
Equatorial rivers have regular regimes but in the UK where seasons exist one or two peaks may be recognisable.
Simple regimes: these show times of high water levels followed by lower levels. They exist as a result of a glacier melt, Snowmelt, or seasonal rainfalls such as monsoons.
Complex regimes: if a river has more than one period of high water levels and/or low water levels, this results. It is more common on large rivers that flow through a variety of relief and receive their water supply from large tributaries, for example, the Rhine.
Two types of flow:
Laminar Flow: This rarely occurs, water flows smoothly in a straight channel. It is most common in the lower parts of a river.
Turbulent flow: This is far more common, it occurs where the shape of the rivers channel is varied with pools, meanders, and rapids. A great deal of turbulence results in sediment being disturbed. The greater the velocity the larger the quantity and size of particles that can be transported.
Bradshaw Model
The Bradshaw model, developed by Dr. Anthony D. Bradshaw in the 1980s, provides a framework for understanding the relationships between various factors that influence the morphology (shape and form) of river channels.
This model is especially helpful in analyzing natural, unmodified rivers, although it can also be applied to modified systems with some adjustments.
Key Variables:
Discharge: The volume of water flowing through a channel at a given time. This is the primary driver of channel morphology, with higher discharge leading to wider, deeper channels.
Sediment supply: The amount and size of sediment (sand, gravel, etc.) entering the channel. High sediment supply can lead to braided channels, while low supply can result in meandering channels.
Channel slope: The steepness of the channel bed. Steeper slopes promote faster flow and deeper channels, while flatter slopes encourage meandering and deposition.
Bank material: The strength and cohesion of the material forming the riverbanks. Stronger banks are more resistant to erosion, allowing for steeper channel slopes and narrower channels.
Vegetation: The type and extent of vegetation along the banks and within the channel. Vegetation can stabilize banks, reduce erosion, and influence sediment transport.
Relationships and Interactions:
The Bradshaw model emphasizes that these variables are not independent but interact and influence each other.
High discharge may increase sediment transport capacity, leading to adjustments in channel width and depth.
Channel slope can influence the size of sediment transported, impacting bank erosion and channel form.
Bank material plays a role in how the channel responds to changes in discharge and sediment supply.
Vegetation can modify flow patterns, trap sediment, and influence bank stability.
Hydrographs
The drainage basin system is said to be open as both inputs and outputs of energy and material occur.
All rivers receive a water from it.
The boundaries of the basin are known as the watershed and will usually be marked by areas of higher land.
Drainage basins have many different characteristics that influence how quickly or slowly the main river within them responds to a period of intense rainfall, these are outlined in more detail in the section relating to storm hydrographs.
Physical Factors affecting river discharge:
Impermeable Rock (e.g. granite) - Water is unable to infiltrate through, resulting in more surface runoff, increasing volume of the channel and its speed.
Permeable Rock - More infiltration, resulting in less surface runoff and less volume in the river
Size of drainage basin - Small -> Water will enter the river quicker and faster
Relief of drainage basin - If the slope of the basin is more steep, water in the river is likely to move down faster, increasing its speed
Percipitation - heavy rain can cause saturation in the soil and hence cause more water to reach the river (runoff). This also means that the speed of the river increases.
Vegetation - allows more infiltration and interception, causing less surface-runoff and slowing down the speed of the river
Human Factors Affecting River Discharge:
Impermeable man-made surfaces - Concrete and tarmac can cause rivers in urban drainage basins to have a higher discharge due to higher amounts of surface runoff. Speed is also increased due to drainage systems and ground.
Destruction of vegetation (deforestation) - Less infiltration + interception causes more surface run off and increases speed of the water.
River Management - Presence of dams allow river flow to be controlled, which may cause more discharge (before the dam) , or less (below the dam).
Base flow - the normal day to day discharge of a river
The rising limb - the rapid increase of discharge resulting from a rainfall.
Peak flow - when the river reaches the maximum capacity that it can hold.
The recession limb - when the discharge starts to decrease and river levels fall.
Basin lag time - the time difference between the peak of the rain event to the peak flow.
Factors that affect shape of Hydrograph:
Drainage basin
Type of rock (impermeable or permeable) - Impermeable rock will not allow water to seep in, thus causing larger amounts of surface runoff and a shorter lag time.
The gradient of the drainage basin - Steep gradients will cause greater overland flow and a shorter lag time.
Size of drainage basin - larger basins will take longer to reach the river, hence a longer lag time
Present conditions of the drainage basin - soil either saturated, very dry or even frozen
Shifts and Changes to Curve
Type and amount of Precipitation
Rapid rain - soil will saturate at a very rapid rate, excess water quickly transfers by surface runoff thus causing a short lag time
Land Use and Human Impact
Impermeable man-made surfaces - e.g. concrete and tarmac roads, shorter lag times
Vegetation area -infiltrates more and intercepts water, a longer lag time, reducing discharge
Area of deforestation - short lag time, increases discharge
Time/season of the year
Summer - evapotranspiration rates are higher, reducing surface run off, longer lag time
Temperatures
Water Use
Dams and reservoirs near area - slow down the rate of discharge, a much longer lag time, and may also cause a reduced amount of discharge
Case Study: Floods
Flooding in Rio de Janeiro (2011)
Located in the south east of Brazil and is the capital of Rio de Janeiro state flood started on 11 Jan. and continued for days after floods and mudslides killed over 900 people and lost over 3000 homes which caused $1.3 billion of damage
Much of the state is on the drainage basin of the river Paraiba do Sul - total area of 57000km squared
Human Causes:
Deforestation of hillsides - reduced strength of hills by removing root system, decreases interception and transpiration, which means that soil becomes saturated more quickly (also increase in surface run-off causing landslides)
Building on marginal land - increasing rates of rural-urban migration meant more building on marginal land (includes floodplains and steep slopes unsuitable for settlement building)
No building regulations - informal settlements (favelas) on marginal land, vulnerable during times of flood; most will not have any drainage system, which increases saturation of soil and likelihood of floods
Population density - any flood is going to affect a large population
Poor transport and communication - many poor people received no warning because they had no access to media sources; rescue efforts were also made much more difficult
Physical causes:
Steep drainage basin and valley sides - mountainous areas and steep valleys mean rainfall reaches streams and rivers very quickly causing flash floods
High levels of precipitation
Tropical climate - south east of Brazil experiences over 4m of rain a year, meaning that during the summer, the ground remains largely saturated, thus decreases infiltration rates and increases surface run-off
Mudslides - secondary hazard of flood water; flood water saturated the ground, increases stress on slopes, causing mudslides
Flooding in Bangladesh
Much of Bangladesh has been formed by deposition from 3 main rivers - the Brahmaputra, the Ganges, and the Meghna
Sediment from these and over 50 other rivers form a large delta (80% of Bangladesh is located on the delta, thus under the threat from flooding and rising sea level)
Densely populated (900 people per km squared) and rapid growth (2.7% per annum)
High total rainfall and very seasonal - 75% of annual rainfall occurs in the monsoon between June and September
Ganges and Brahmaputra carry snowmelt waters from the Himalayas
Peak discharges are immense (due to snowmelt in the Himalayas combined with heavy monsoonal rain) - up to 10,000 cumecs
Types of flooding - river floods, overland run-off, flash floods, back-flooding and storm surges
Reasons for flooding:
Discharge peaks of big rivers
High runoff from the Meghalaya Hills
Heavy rainfall
High groundwater tables
Spring tides
Causes and Effects
Outside monsoon season, heavy rainfall cases extensive flooding (leads to destruction of agricultural land); however, may be advantageous to agricultural production due to new source of nutrients
Effects of flash floods due to heavy rainfall in northern India have been intensified by destruction of forest, which reduces interception, water retention and increases rate of surface run-off
Human activity exacerbated the problem - attempts to reduce flooding by building embankments and dikes have prevented the back flow of flood water into the river - leads to a ponding of water (drainage congestion) and back-flooding
Embankments have led to a increase in deposition in drainage channels and can cause large-scale deep flooding
Coastal flooding - storm surges caused by intense low-pressure systems are funneled up the Bay of Bengal
4750 people killed, 130,000 cattle killed, 660,000 hectares of crops damaged
66% of land flooded
23m made homeless
400 factories closed, 11000km of roads damaged, 1000 schools damaged or destroyed
Advantages of flooding:
Flood waters replenish groundwater reserves
Provide nutrient-rich sediment (alluvium) for agriculture in dry season
Provide fish (fish supply makes up 75% of dietary protein and over 10% of annual export earnings)
Reduce need for artificial fertilizers
Flush pollutants and pathogens away from domestic areas
Management Issues and Strategies
Dams and Reservoirs
Dam: a barrier constructed to hold back water and raise its level, forming a reservoir used to generate electricity or as a water supply.
Reservoir: a large natural or artificial lake used as a source of water supply.
Multipurpose scheme: a scheme or project built for more than one purpose. For example to prevent flooding as well as irrigate the land and also generate HEP
Hydrological changes resulting from the construction of dams and reservoirs:
Changes to the hydrology upstream of dams –
Increased evaporation rates because reservoirs have a larger surface area than rivers.
An increase in the amount of surface store (reservoirs are an artificial store).
A reduction in the velocity of the river upstream.
The river was effectively flowing into a stationary store of water.
Increased sedimentation can lower the depth of the river and the reservoir.
Again this will reduce velocity and may also reduce storage capacity.
Changes to the hydrology downstream of dams –
River discharge will decrease because water is being held behind the dam.
A rivers’ discharge may become more regular (less extremes) because the flow of water is regulated.
Clear water erosion may cause the bed of the river to lower.
There is no sediment (load) to be deposited to replace erosion.
The amount of load transported by the river will reduce because less sediment is reaching downstream.
The salinity of the water and the ground may increase.
The temperature of the water may reduce, as water released from reservoirs is often colder (reservoir deeper than river).
The water may also be less oxygenated than natural free flowing water.
With smaller discharge the velocity of the river may decrease, because the level of the river is further below bank-full discharge so the hydraulic radius is smaller.
The amount of depositional landforms may reduce e.g. alluvial fans, levees, deltas and slip off slopes.
Case Study: Dams
Aswan Dam on the River Nile
Built on the River Nile, south of the city of Aswan in Egypt
2 dams - Aswan Low Dam and Aswan High Dam (completed in 1902 and 1970)
Advantages:
Flood and drought control - dams allow good crops in dry years, e.g. 1972 and 1973 in Egypt (reduces dependency on food imports)
Irrigation - 60% of water from the Aswan Dam is used for irrigation and up to 4000km of the desert are irrigated
HEP - accounts for 7000m kW hours each year (45% of Egypt’s energy needs)
Improved navigation upstream and downstream due to less seasonal variations downstream as the amount of water released is regulated (improved tourism on the river Nile)
Recreation and tourism (dam itself is a tourist attraction)
Amount of fishing behind the dam increased, supporting local fishing industry
Building and maintenance of the dam created many jobs and taught local workers new skills
(Estimated that the value of the Aswan High Dam to the Egyptian economy is about $500m each year)
Costs:
Water losses - dam provides less than half the amount of water expected
Salinization - crop yields have been reduced on up to ⅓ of the area irrigated by water from the dam due to salinization
Groundwater changes - seepage leads to increased groundwater levels and may cause secondary salinization
Displacement of population - up to 100,000 Nubian people have been removed from their ancestral homes
Seismic stress - earthquake of November 1981 is believed to be caused by the dam; as water levels in the dam decrease, so does seismic activity
Channel erosion (clear water erosion) beneath the channel; lowering the channel by 25mm over 18 years
Increased sedimentation may put stress on dam, reduce lake depth, storage levels and preventing the nutrients from reaching farmland downstream
Loss of nutrients - $100m worth of artificial fertilizers used annually to replace nutrients (alluvium) trapped behind the dam
Decreased fish catches - sardine yields are down 90% and 3000 jobs in Egyptian fisheries have been lost
Spread of diseases due to increased stagnant water
Floodplain Management
Channel Prosses and Fluvial Forms
Erosion:
Erosion is the wearing away of something. When talking about rivers it normally means the wearing away of the bed, banks and its load. Types of erosion are:
Attrition:
This when load in a rivers flow crash into each other, causing pieces to break off.
Hydraulic Action:
This is when air and water gets trapped in cracks on a rivers beds and banks. The build up of pressure within the cracks causes bits of the bed and banks to break off and the cracks to get bigger.
Corrosion (solution):
When the slight acidity of water cause bits of load and the bed and the banks to dissolve.
Corrasion (abrasion):
When bits of load crash into the bed and banks. This process causes the load, bed and banks to wear away.
Transportation
When a river has surplus energy it may carry some of the material that it has eroded. The different types of erosion are:
Traction: Load that is rolled along the bed of the river.
Saltation: Load that is bounced along the bed of the river.
Suspension: Load that is transported in a rivers’ flow (current).
Solution: Load that is dissolved by a river and then transported by it.
Flotation: Material transported on the surface of a river.
Deposition
When the velocity of a river falls causing its energy to fall.
Because the energy of the river is falling so does its capacity and competence, causing to put down its load. This process of putting down load is deposition.
Hjulstrom Curve: A graph that shows the relationship between river velocity and particle size when looking at a rivers’ ability to erode. transport and deposit.
The Hjulström Curve is a graph used to determine whether a river will erode, transport, or deposit sediment depending upon the flow velocity.
The x-axis shows the size of the particles in mm.
The y-axis shows the velocity of the river in cm/s.
Competence: The maximum diameter of a piece of load that a river can transport.
Capacity: The maximum amount of load that a river can transport.
Critical Erosion Velocity: The minimum velocity that a river needs to be traveling for it to start eroding and then transporting material.
Settling (or fall) Velocity: The velocity that a river needs to fall below to start depositing its load.
What apparent anomaly with the Hjulstrom curve is that it can erode sand at a much lower velocity than it can erode clay and silt.
This is because that clay and silt are very cohesive (they stick together).
This means that even though the particles sizes are small they have a very strong bond between them.
Upper Course
The upper course is nearest the source.
This is where load is biggest and most erosion is vertical.
Most landforms are made by erosion and include; waterfalls, gorges, rapids, v-shaped valleys and interlocking spurs.
Alluvial River: any river that carries load.
Nearly all rivers (except some rivers flowing over ice shelves and glaciers) carry load.
Fluvial: Anything found on or made by a river. This includes all landforms.
Characteristics:
Lowest volume of water
A narrow channel with a steep gradient;
The river erodes downwards.
This vertical erosion results in a number of distinctive landforms including:
V shaped valley cross section
narrow valley floor
interlocking spurs
river's load is of various sizes and angular.
V-Shaped Valley Formation:
Vertical erosion in the river channel
Weathering of the sides of the valley sides
Mass movement of materials down the valley sides,
Material is gradually transported away by the river.
As the river flows through the valley it is forced to swing from side to side around more resistant rock outcrops (spurs).
As there is little energy for lateral erosion, between spurs of higher land creating interlocking spurs
Middle Course and Lower Course:
The middle course when the river leaves the mountains and enters are more hilly environment.
The valley floors starts to widen as you get more horizontal erosion.
The landforms found in the middle course include alluvial fans and meanders.
The lower course is closest to the mouth.
Here the river is travelling over much flatter land and the load is much smaller and smoother.
This is more horizontal erosion here as the river nears its base level.
The landforms found in the lower course include meanders, oxbow lakes, braided rivers, levees and deltas
Meander:
A meander is when water flows in a curvy, bendy path, like a snake.
As a river makes its way through an area that is relatively flat, it often develops bends as it erodes its way through the path of least resistance.
Forms as a watercourse erodes the sediments of an outer, concave bank and deposits sediments on an inner, convex bank (point bar), leading to a meandering channel
Oxbow Lake:
An oxbow lake is a meander that has become cut off from the main river channel.
If you have the outside of two meanders near each other they will eventually connect.
They connect because erosion is at its maximum on the outside of the meander.
When they eventually connect the thalweg (fastest flow) will no longer go around the old meander, but actually go in a straight line.
This means that the outside of the river channel now has a slower flow so deposition takes place cutting off the old meander.
Braided River:
A braided river is a river with a number of smaller channels, separated by small and often temporary islands called eyots.
Braided rivers usually form on rivers with the variable flow (wet and dry season or snow melt season) and high quantities of load.
When a river is at maximum discharge it is able to transport most of its load.
However, when the discharge falls along with the velocity an energy of the river, deposition starts to take place, creating eyots.
Delta:
Form when a river tearing sediment reaches a body of water
Deltas are found at the mouth of a river, where the river meets the sea.
At this point the river is carrying too much load for its velocity and so deposition occurs.
The top of the delta is a fairly flat surface.
This is where the coarsest river load is dropped.
The finer particles are carried into deeper water.
The silt is dropped to form a steep slope on the edge of the delta while the clay stays in suspension until it reaches the deeper water.
Levees:
Levees are embankments found on the sides of a river channel. Levees can be made by or enlarged by humans, but we are only interested in levees that are made naturally.
Levees are made when a river exceeds bankfull discharge i.e. it is in flood.
Floodplain:
The floor of the valley floor that gets flooded when a river exceeds bankfull discharge.
Floodplains tend to be much wider in a rivers’ lower course where horizontal erosion has had a greater effect.
Bluff line:
The outer limits of the floodplain.
The bluff line is basically the edge of the valley floor.
Strand line:
A line of load (usually sticks and litter) that is deposited at the limit of a flood.
Alluvial deposits (alluvium):
Load that is deposited by a river in time of flood.
Floodplains and leveés are formed by deposition in times of river flood.
The river’s load is composed of different sized particles.
When a river floods it deposits the heaviest of these particles first. The larger particles, often pebble-sized, form the leveés.
The sands, silts and clays are similarly sorted with the sands being deposited next, then the silts and finally the lightest clays.
Every time the river floods deposition builds up the floodplain.
Meanders & Oxbow Lakes
deposition and erosion
Floodplains, Levees & Deltas
deposition
The river is now flowing over flatter land and so the dominant direction of erosion is lateral (from side to side).
The river has a greater discharge and so has more energy to transport material. Material that is transported by a river is called its load.
Deposition is also an important process and occurs when the velocity of the river decreases or if the discharge falls due to a dry spell of weather.
Materials Transported Downhill:
Traction: boulders and pebbles are rolled along the river bed at times of high discharge
Saltation: sand sied particles are bounced along the river bed by the flow of the water
Suspension: Find clay and sans particles are carried along within the water even at low discharges
Solution: some minerals dissolve in the water (Ex. Calcium carbonate). THey require little energy
Case Study: Floodplain Management
River Conwy, North Wales - Floodplain Management
Source in Snowdonia and mouth in the Irish Sea
Only 27 miles long but has regular floods
Steep gradient and sits on impermeable slates (little infiltration, high rates of surface run-off)
Weather near source is very wet, receives up to 4m of rainfall a year
During spring, the river is also fed by snowmelt
Deforestation and tidal rivers make it very prone to flash floods
Flood in 2005 damaged railways, roads, farmland, parkland, houses and businesses
Management techniques used:
River wall - a 3m concrete wall built to protect the village of Llanrwst
River training - rocks placed in river channel to slow river near village and cause deposition (redirected away from village)
Channelization - little tributaries that flow through Llanrwst have been lined with concrete; aim is to get water through the villages quicker by reducing friction
Embankments levees - raised banks built along river sections to increase river’s cross-sectional area and reduce flood risk
Raised buildings and pathways - built on stilts so they don’t get damaged if river bursts its banks
Controlled flooding - low value farmland allowed to flood to protect high value settlements
Flood proofing houses - designed with no carpets and removable furniture on lower floors
Human Modifications to Floodplains
Urbanization: Urbanisation tends to cause deforestation reducing interception and transpiration. Sewers also reduce surface stores and therefore evaporation. Urban areas usually create large impermeable surfaces which can lead to greater surface run-off.
Sewer Systems: Generally sewer systems create artificial channels, which often reduces a rivers’ lag time and can lead to increased flooding downstream.
Pollution: Transport, industry and housing all create pollution which works its way into the water system. Areas that don’t have proper sewers and water treatment tend to be effected more. Metals and chemicals are particularly polluting.
Water table (groundwater depletion): Unsustainable use of groundwater can cause subsidence.
Mexico City has experienced subsidence because of aquifer depletion underneath the city. On the scale, London has actually seen its water table rise since deindustrialisation has meant the demand for water has fallen.
Deforestation: Deforestation reduces interception and transpiration. Removal of trees can also increase the risk of mudslide by reducing slope stability and stops root uptake. Less interception speeds up the rate the ground become saturated and therefore increases the risk of flooding
Micro-climate: Urban areas create heat islands which can increase convectional rainfall. Particulates released by industry and transport also make excellent condensation nuclei.
Channelization: Artificially smoothing channels may remove river discharge from one area, but areas down stream that haven’t been smoothed are likely to experience an increase risk of flooding.
Alternative Stream Management Strategies
Channel Enlargement (widening/deepening): Making the width and depth of the river wider and deeper to increase its cross- sectional area.
Advantages: By enlarging the cross-sectional area you are increasing the bankfull discharge of the river along with its hydraulic radius.
This will increase the velocity of the river and reduce the chances of it flooding in the immediate area by moving the floodwater further on downstream.
Disadvantages: If buildings are built up to the river bank it might not be possible to enlarge the channel.
Also the process can be expensive and can cause problems to areas downstream who are receiving more flood water quicker, but with an un- enlarged channel.
Channel Straightening: Removing meanders from a river to make the river straighter.
Advantages: By removing meanders the velocity of the water through a settlement will increase.
This will stop a backlog of water and should reduce the risk of flooding. It also improves navigation.
Disadvantages: By changing the course of the river, you might remove flowing water from industries that depend on it.
There might also be building that have to be demolished to allow straightening.
Again it is expensive and may cause flooding problems downstream.
Flood Relief Channels: Building new artificial channels that are used when a river nears bankfull discharge.
Advantages: They take the pressure off the main channels when floods are likely therefore reduce flood risk.
Disadvantages: It can be hard find land to build relief channels, they are expensive and when empty can become areas to dump rubbish, etc.
If river levels rise significantly it is also possible for relief channels to flood as well
Artificial Stores: Creating reservoirs or lakes that can store excess water in times of flood.
Advantages: They can remove pressure of the main channel and can become new habitats and serve other purposes e.g. leisure, drinking water.
Disadvantages: Building dams, sluices, diversion channels are all expensive.
They also involve flooding areas of land which may be hard to find near large vulnerable urban populations
Flood Embankments (levees): Like levees these increase the channel depth of a river, raising its bankfull discharge and reducing the risk of flood.
Advantages: They increase the cross-sectional area of the river and therefore its hydraulic radius.
This should reduce the risk of flooding.
Disadvantages: Like in New Orleans under extreme conditions, embankments may fail causing even bigger problems.
They are expensive to build and again may cause problems downstream.
Controlled Flooding: Allowing low value land e.g. farmland to flood, therefore protecting higher value areas.
Advantages: By allowing the river to flood naturally you are taking the pressure of high value areas, you are letting the river behave more naturally and it adds alluvium to the floodplain.
Disadvantages: You have to make the decision what is worth protecting which is always going to upset someone.
You also have to protect areas that you don't want to flood which costs money (cost benefit analysis)
Afforestation / Reforestation: Simply planting more trees in a drainage basin.
Advantages: This is a natural process, increasing the amount of interception, transpiration and root uptake.
People would not normally protest against trees being planted.
Disadvantages: It is not possible to cover the whole drainage basin in trees, so if it rains in an area with no trees, then there is no reduction in flooding.
Also, most trees lose there leaves in autumn and winter reducing interception in those months.
Flood Proofing: This is making property less vulnerable to flooding or flood damage. This might be temporary like using sandbags or design by removing carpets downstairs.
Advantages: This can be done on an individual level and can be relatively cheap.
Temporary protection can be removed under normal circumstances so it does not change the aesthetics of properties.
Disadvantages: Temporary defences can usually only protect against minor floods.
Not everyone will be happy with having to redesign their houses.
Insurance: Although it doesn't prevent flooding, it can help individuals and industries to recover and protect against future flooding.
Advantages: It helps individuals and settlements to recover after flood events and may help them protect property and be less vulnerable in the future.
Disadvantages: They do not actually prevent flooding.
Not everyone can afford insurance and insurance companies may not insure high risk areas.
Land Use Planning (zoning): Mapping areas by looking at there likelihood to flood and then only building low value uses on areas with high flood risk.
Advantages: Very good at removing high value areas and high density populations from hazardous areas.
Disadvantages: It is not always possible to change land uses that already exist in an area.
You have to decide what size flood to map for e.g. a once in ten year flood or once in one hundred year flood.
Often poor will still choose to live on marginal land.
Contour Ploughing and Strip Cultivation: Either creating temporary surface stores or leaving vegetation to increase interception and transpiration
Advantages: Contour ploughing is simply a cheap and easy change in existing farming methods.
Keeping vegetation is natural and relatively cheap.
Disadvantages: Won't protect against big floods and farmers may not be happy giving up farmland, simply to grow trees.
Interception Channels: These are channels that divert a rivers' discharge around settlements.
The old channel remains but with a smaller discharge.
Advantages: They remove pressure of the main river and areas of high land value.
They may also develop into new habitats for plants and animals.
Disadvantages: They are expensive, may flood themselves in times of heavy floods and may restrict future urban
Settlement Removal: Moving settlements from high risk flood areas to less vulnerable locations often on higher land.
Advantages: Is probably the most effective because you remove high value property and humans from vulnerable areas.
Disadvantages: It is usually not practical to move whole settlements, because of the cost and the problems of finding alternative locations.
Also many settlements depend on water for their survival.
Dams: Often built as part of a multipurpose scheme, they create artificial stores which can hold water in times of increased precipitation.
Advantages: They can store large amounts of water and can be used for other purposes.
Disadvantages: If rain is downstream of the dam then they have no effect.
In large flood events they are vulnerable to breaking and are expensive to build.
Wing Dykes: Barriers placed out into a river, these can be used to divert the cause of rivers by shifting the thalweg of rivers.
This may move the channel away from high value areas.
Advantages: They can move the main channel from vulnerable areas to protect high value areas.
Disadvantages: They are expensive to build and during big flood events the flood water may go over the wing dykes.
Also if there is property on both sides of a river, which side do you protect.
Electronically Controlled Sewers: Advanced sewers which can control the flow of rain water tostop increased discharge into rivers and therefore flooding.
Advantages: They can be very effective at controlling smaller floods.
They are underground so do not cause any visual pollution.
Disadvantages: This involves a complete redesign of sewers.
Sewers usually have to be increased in size and electronic sluices have to be added.
They also have to be operated from a central command centre and with all electronically operated equipment can break.
Also they might not be able to cope with large scale floods, so water has to be released into rivers anyway.
Channelization: The concreting of beds and banks.
Advantages: Reduces friction and increases velocity of river, removing water from the channelised area quicker.
Bank erosion is also reduced.
Disadvantages: It is expensive and is not natural so vegetation and animal life will find it harder to grow and live.
Flooding maybe caused downstream of the channelised area.
Dredging: The removal of material from the bed of the river deepening it.
Advantages: Channel cross-section is increased so the river can hold greater discharge.
It can look more natural because no structures are built.
Disadvantages: Deposition can mean that dredging needs to happen regularly.
River bank conservation: Protecting the banks and sides of the river to reduce erosion.
This can be done through planting vegetation.
Advantages: It looks natural, promoted wildlife and is relatively cheap compared to hard-engineering.
Disadvantages: During large flash floods vegetation can be easily removed.
River restoration: Returning a river to its natural state before it had been managed. This might involve removing channelization.
Advantages: This looks natural, is attractive and can attract wildlife. Can allow the floodplain to become more fertile.
Disadvantages: Can't protect against big floods and may have to coincide with zoning
Groundwater Management
Key Terms
Artesian basin: An artesian basin or aquifer is a confined aquifer containing groundwater under positive pressure.
This causes the water level in the well to rise to a point where hydrostatic equilibrium has been reached (balance between pressure on the aquifer and pressure from the aquifer).
Aquifer: Rocks that can hold water.
Saturated: When all pore space is full and rocks or soil can hold no more water.
Groundwater: Water held under the surface of the earth.
Depletion: When something is reducing, aquifers can become depleted in dry periods or when they are managed unsustainably.
Aquiclude: Rock that will not hold water or allow its movement. i.e. they are non-porous and impermeable
Causes of Groundwater Usage:
Evapotranspiration from shallow stores, capillary action will draw moisture up to near the surface
Natural discharge by springs and into lakes, rivers and oceans
Artificial abstraction (removal) for domestic, industrial and agricultural use
Leakage into nearby aquifers
Interbasin transfers
Causes of Groundwater Recharge:
Artificial recharge. Either leakage from irrigation channels and reservoirs or the pumping of water into aquifers.
Infiltration and percolation after precipitation or snow melt
Seepage from river channels, lakes and oceans
Leakage from nearby aquifers
Interbasin transfers
Case Study: Groundwater Management
Groundwater Pollution in Bangladesh - Groundwater Management
Increase in incidence of cancers in Bangladesh
Caused by naturally occurring arsenic in groundwater pumped up through tube wells
As many as 85m of the country’s 125m population will be affected by arsenic-contaminated drinking water
UNICEF has sunk millions of tube wells in Bangladesh, providing a convenient supply of drinking water free from bacterial contamination of surface water
But the water from wells was never tested for arsenic contamination, which occurs naturally in the groundwater
1 in 10 who diners water containing arsenic will ultimately die of lung, bladder or skin cancer
Arsenic poisoning is a slow disease - skin cancer occurs 20 years after people start ingesting the poison, then internal cancers
One solution is a concrete butt, collecting water by pipe from gutters
Another is a filter system
Freshwater Wetland Management
Wetland is an area of land where soil is saturated with moisture either permanently or seasonally.
Such areas may also be covered partially or completely by shallow pools of water. Wetlands include swamps, marshes and bogs.
The water found in wetlands can be saltwater, freshwater, or brackish (a mixture of fresh and salt water).
The world’s largest wetland is the Pantanal which straddles Brazil, Bolivia and Paraguay in South America.
Brackish water: Water that has a higher salinity content than freshwater, but not as high as saltwater.
Importance of Wetlands
Flood control:
Many wetlands are covered in vegetation which can intercept precipitation, absorb rainwater and transpire water.
Wetland vegetation can also reduce the velocity of rivers flowing into them or from them and act as natural stores of water.
If you remove or drain areas of wetland more pressure is placed upon the main river channel.
Coastal and marine wetland areas can also absorb the energy of tropical storms, tsunamis etc.
Groundwater recharge:
Wetlands can collect large areas of precipitation and river discharge.
As this water is held in storage it will infiltrate and percolate into the ground to recharge groundwater.
Transport Network:
Wetland provide many natural waterways that people can move around on easily.
Tourism and Leisure:
Some wetlands, like the everglades in Florida or the fens in East England become tourist attractions.
They also become popular locations to bird watch, fish and hunt.
Flora and Fauna:
Many wetlands are unique habitats that support indigenous aquatic plants and animals.
Many wetlands support rare reptilian and amphibian species.
Many migratory birds also rest in wetlands flying to and from nesting and breeding grounds.
Fisheries:
Wetlands can support large numbers of fish which can support local populations.
Wetlands are not normally viable commercial fisheries.
Water purification:
The soils, geology and vegetation of wetlands can help clean and purify water.
Storage of organic matter:
Wetlands support large areas of organic matter that can hold large stores of methane (greenhouse gas).
Coastal stabalisation:
Wetlands that occur along the coastline and on river banks have prevent erosion from the sea or by rivers.
Factors Causing Loss and Degradation of Wetlands
Increased demand for agricultural land:
As the world population grows there is an increasing demand for food.
With the amount of viable agricultural land decreasing, increasingly areas of wetland are being artificially drained to make ways for agricultural land e.g. the draining of the fens in East England.
Population growth:
As the world’s population grows, it demands more water, more food and more land.
The increasing demand for water can mean wetlands are drained of their water or their source of water.
This problems is made worse as the world’s population develops and uses more water e.g. showers and toilets.
Urbanization:
With the world population growing, there is a greater demand for housing. Increasingly this demand for housing is in urban areas.
With urban areas growing more and more wetland areas are being drained or inhabited.
Urbanisation on or near wetlands can cause pollution, changes in river flow and river channels and disturbance of wildlife.
Land reclamation is the process of reclaiming land from the water.
Sea level rises:
Global warming is causing glaciers and ice sheets to melt causing sea levels to rise.
These rising sea levels can flood coastal and marine wetland areas.
Even if the whole wetland is not flooded, water conditions can be changed from fresh to brackish.
River flow changes:
Many rivers have been channelised and straightened, reducing the amount of wetlands.
Others have been drained or dams have altered flow.
Some have been polluted or redirected.
All these natural changes are removing or changing the ecosystems of many wetland areas.
Pollution:
Any form of pollution, but particular chemicals and metals can change the delicate ecosystems of wetlands.
Process like eutrophication, caused by fertiliser run-off can completely kill whole wetland areas by preventing the wetland oxygenating properly and receiving sunlight.
Infrastructure projects:
As populations grow and we become more mobile, there is an increasing demand for new roads, airports, railways. etc.
Unfortunately wetlands are often drained or disrupted (bridges, dykes and causeways) to make way for these projects.
Alien species invasion:
Many alien species like the cane toad in Australia or the American mink in the UK have been introduced to wetlands and devastated indigenous species.
The introduction of any alien, however small can disrupt food webs and ecosystems.
Tropical storms:
Although wetlands can be a natural defence against tsunamis and tropical storms, they can also been damaged by them.
Freshwater wetlands in particular can be flooded by storms surges associated with tropical storms, changing the salinity of water and damaging vegetation.
Case Study: Wetland Management
Kissimmee River - Wetland Management
In south central Florida, drainage basin of 7800km squared and approximately 200km long was home to wetland plants, fish and wading birds.
However, the 5km wide floodplain with populated settlements nearby were regularly flooded.
Thus, the river was channelized and transformed into a 90km, 10m deep drainage canal - to provide an outlet canal for draining floodwaters from upper Kissimmee lake basin and to provide flood protection for land adjacent to the river
Impacts of channelization:
Loss of 12000-14000 hectares of wetlands
Floodplain dried up after channelization - no longer exceeds bankfull discharge
Egret, heron, and wood stork populations decreased by ⅔
Catches of largemouth bass decreased
Fishing, bird watching and hunting tourism declined
Concerns about the sustainability of existing ecosystems led to the Kissimmee River Restoration Project (large scale, supported by the state and federal)
Aim: restore over 100km squared of river and wetland floodplain by 2015
Started in 1999
River is being de-channelized by refilling the flood canal and re-establishing the old natural course of the river
Restored sections now flood naturally - restored floodplains could benefit avian species e.g. wading birds and waterfowl, by providing increased feeding and breeding habitats
Dissolved oxygen levels have doubled in restored sections
Increase in revenue from tourism potential could significantly enhance local and regional economies
Possible negative impacts from restoration:
Greater evaporation due to more surface stores
Increase risk of flooding
River will be less navigable in dry periods
Restoration will cost $578m
Agriculture and Irrigation
Agriculture:
Agriculture the artificial cultivation (growing or rearing) of plants or animals.
Agriculture that grows crops is known as arable agriculture, agriculture that involves rearing animals is known as pastoral agriculture.
Irrigation:
This means artificially watering the land.
There are three main types of irrigation; gravity flow, sprinklers and drip systems.
Eutrophication:
This is the processing of artificially adding nitrates and phosphates (through fertilsers and sewage) to wetland areas e.g. rivers and lakes.
The added nitrates and phosphates causing excessive growth of algaes.
The algae growth can reduce the oxygen content of the water as well as reducing the amount of sunlight that it receives.
The nitrates and phosphates often come from agro-chemical run-off, but can also come from domestic sewage and industrial waste.
Salinisation:
This is the increase in the salt content of water.
Salinisation can happen because of evaporation or unsustainable water extraction.
If the water become to salinated it becomes less fertile.
Growing Demand for Agricultural Products:
The world’s population is growing.
The current population is about 7 billion, but it is expected to peak at nearer to 9 billion.
Because fossil fuels are finite, alternative forms of energy are being looked at.
One form of renewable energy being used are biofuels.
Biofuels are made out of biological matter and therefore are increasing the demand for agricultural products.
Economic development.
As more of the world’s population is removed from poverty, their calorific intake increases.
This increase in food consumption, is increasing the demand for agricultural products.
Pastoral farming.
As the world population increase, the demand for meat also increases.
Most farm animals are omnivores or herbivores so need agricultural products like corn to eat.
Decreasing Supply of Agricultural Products or Land
Urbanisation.
As the world develops, urbanisation increases tends to happen increasing the size of urban areas.
As urban areas grow they eat into greenfield sites in rural areas, reducing the amount of agricultural land.
Land degradation and desertification.
Land that is overcultivated or overgrazed can become degraded (less fertile).
As farmers try to react to demand by growing more intensively, more land is being degraded.
In extreme circumstances, the land may turn to desert (desertification).
Rising sea levels.
Some of the earth’s most fertile agricultural areas are floodplains and deltas.
As world sea levels (eustatic changes) increase much of this fertile land is lost.
Conversion to biofuels.
Although not strictly reducing the amount of agricultural products (biofuels are agricultural products), this does decrease the supply of agricultural products available for human consumption.
Biofuels are often favoured by farmers, because they demand a higher price.
Hazards.
Natural hazards like tropical storms, volcanoes and tsunamis can reduce the amount of agricultural land available for cultivation.
Disease.
There is an increasing amount of intensive monoculture (growing of one crop) taking place.
Monoculture always runs the risk of been impacted by the outbreak of diseases or pests that attack the particular crop e.g. wheat leaf rust fungus.
Competing Demand for Water
Competition on Local Scale
Case Study: Local Scale Competition for Demand for Water
Israel’s Aquifers - Demand for Water: Local/national Scale
Water is one of the most sensitive and unsolvable problems in the Middle East
Created friction between the Arabs and Jews (Israeli-Palestinian tensions)
For decades, Israel has obtained up to 80% of the 670m cubed of water provided by mountain aquifer mostly located under the West Bank
Israelis have occupied the West Bank since 1967 and have prevented the Palestinians from obtaining better access to the resource
Mountain aquifer is important for Israel as it provides:
⅓ of its water consumption
4% of its drinking water
50% of its agricultural water
120,000 Jewish settlers in the West Bank use 60m cubed annually compared to 137million m cubed used by 1.5m Arabs
The WB and Gaza are served by Israel’s water carrier and groundwater in aquifers
WB’s aquifers, replenished by rainfall, flow west, north, and east from the watershed
Palestinians were forbidden to dig new wells or deepen old ones (Israel claims that they have the right to use the aquifer because some of the water flows into its territory) - thus kept very short for their crops
The Gazans, like West Bankers, get little domestic water from Israel’s national carrier - most of their supplies come from an aquifer that has been exploited - Gazans pump twice as much as can be safely withdrawn, leading to salt water intrusion (kills citrus trees)
Gaza Strip is part of the Palestinian territories - coastal aquifers becoming exhausted and at threat of salt water intrusion and domestics and industrial pollution
Competition on International Scale
Case Study: International Scale
The Mekong - Demand for Water: International Scale
South-east Asia’s largest river flat, well-watered and fertile land in the basin lies around Tonle Sap Lake, but annual flood makes intensive agriculture difficult there surface area of lake can increase up to ten times during the monsoon remained untouched until 1990s
First dam non the river, at Man Wan, in China was completed in 1993
Population growth and economic growth - place strain on the Mekong
HEP potential of the Mekong and its tributaries is considerable - so far, only 5% of the lower basin’s HEP have been developed
Dams generate electricity, aid irrigation and regulate flooding
However, caused damage to fisheries - annual harvest amounts to 2m tonnes
Case Study: International Scale
The River Nile - Conflict at International Scale
Importance of the River Nile:
Tourism - rapids in Uganda
agriculture and irrigation - Egypt depends on the Aswan Dam to irrigate the desert
Transport - promote trade
Wildlife
Drinking water
HEP - drought control
Longest river in the world, 6650km long
2 main tributaries - White Nile and Blue Nile
Confluence is in the Sudanese capital, Khartoum
Source of WN: Burundi
Source of BN: Ethiopia
WN, BN and the Nile flow through 11 countries
Conflicts:
Have arisen since Ethiopia began dam building
In 2010, 6 of 9 upstream countries signed a Cooperative Framework Agreement seeking more water shares from the Nile
Sudan and Egypt rejected agreement because it challenged their historic water allocations
A major dam on the BN, called the Grand Renaissance Dam is under construction by Ethiopians
Egypt, draws much of its drinking water, natural resources, and energy from the Nile, has protested the dam’s construction (will siphon resources away)
Dispute between Egypt and Sudan over the dam construction has reignited a 60-year old dispute (Sudan, downriver of the Nile, has supported Ethiopia’s attempts to build the dam)
Ethiopia denies that the dam would damage Egypt’s water supplies
Egypt now hope to pull the Europeans to its side ad to pressure Ethiopia before protesting before the security council
Egypt has threatened to defend its historical claims over the Nile in numerous occasions - it will even use air power against other countries to protect its flow of the Nile
Oceans and Coastal Margins
1. Introduction to Ocean Currents
Ocean Currents: surface ocean currents are caused by the influence of prevailing winds steadily blowing across the sea
Gyres Ocean Currents: the dominant pattern of surface ocean currents which is roughly a circular flow. This is clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere due to the Coriolis Force due to the Earth’s rotation. The only expectation is the circumpolar current around Antarctica
Gulf Stream Ocean Currents: Narrow flowing current which is the return flow of westward piling water, caused by the circulation of gyres and the Earth’s rotation)
transports heat northwards and then eastwards across the North Atlantic
creates mild winters & cool summers in the British Isles
Transfer of Nutrients and Energy:
Nutrient Transfer due to Ocean Currents: eastern oceans experience upwelling currents, where the ocean currents move nutrient-rich cold water from the ocean flow to the surface
Energy Transfer due to Ocean Currents: Warm currents from regions near the equator raise the temperature of the polar area, while cold currents may reduce summer temperature when the wind blows from sea to land
Specific Heat Capacity: the amount of energy needed to raise the temperature
Takes more energy to heat water than land
Coastal regions are cold during the day and mild at night
The Pacific Ocean
Two atmospheric states: are warm surface water in the west and cold surface water in the east (and vice versa). Warm surfaces cause low pressure, and as air blows from high pressure to low pressure, it causes a movement of water from colder areas to warmer areas
Ocean Conveyor Belt/Thermohaline Circulation (THC): a global thermohaline circulation driven by the formation and sinking of deep water and responsible for a large flow of upper ocean water
Thermocline: the boundary between 200-800m below which the surface waters do not mix with deeper layers; region marked by rapid discrete in temp as depth increases
Halocline (salinity) and Pycnocline (water density): both increase with increasing depth.
Halocline exists in the same depth as thermocline
Salinity rapidly increases and temp decreases, which leads increase in water density
marked by proc line
El Nino vs La Nina:
El Niño: a reversal of the normal atmospheric circulation in the southern Pacific Ocean, beginning arm water and low pressure to the eastern Pacific, and cool water and high pressure to the western Pacific
Occurs once every 2-10 years and lasts 12-18 months
La Niña: intensification of normal atmospheric process
The cold current that flows from the east across the equatorial Pacific Ocean
Occurs when low pressure in the western Pacific becomes even lower
Hurricanes:
Hurricanes (Tropical Cyclones): low-pressure systems; high-intensity rainfall, strong winds, & heavy waves (flooding & mudslides).
Originate from moist, tropical seas; erratic path; winds spiral rapidly around the calm area (eye); pressure contrast = strong gale-force winds.
Move excess heat from low latitudes to higher latitudes; begin as small-scale tropical depressions (low pressure, warm air rises).
Sea = temp. above 27°C and a depth of 60 m; low-pressure area far from the equator (Coriolis force rotates rising air mass); unstable conditions.
Saffir-Simpson scale = assign hurricane to 1 of 5 categories of potential disaster; based on wind intensity; formed in Atlantic and Pacific
Case Study:
Typhoon Haiyan, Philippines
winds of 314 km/hr
10 000 ppl killed & buildings were destroyed
sea waters rise 6 m
World Food Programme = $2 million in aid
economic cost = $15 billion (many countries pledged aid)
vulnerable community (no savings)
Ocean Role and Acidification:
Ocean Acidification: freshwater = pH of 7 & surface seawater = 8.2 (dropped to 8.1) ; absorption of CO2 by oceans ; 0.1 difference = inc. of 30%
Absorbed 50% extra CO2 during the industrial age; anthropogenic causes (human actions); threatened species (fisheries & coral reefs).
30% of human-made carbon absorbed by oceans; reacts and turns into carbonic acid - reducing calcification of organisms (growth rate Dec. 14%).
Pacific coast = failure of commercial oyster; Great Barrier Reef = coral bleaching; Poles / high latitudes = shellfish (pteropod) reduction
Oceans as a Source and Store of Carbon Dioxide: largest CO2 sink (90% of carbon); carbon on ocean floor lifted (thermohaline circulation) = source.
Cold glacial phases = atmospheric CO2 decreased, stored in oceans ; Warm interglacials = CO2 released from oceans (inc. atmospheric CO2).
CO2 reservoirs = fossil fuels, atmosphere, & oceans ; carbon cycle (photosynthesis produce CO2 & released by volcanic activity, long timescale)
2. Interactions Between Oceans and Coastal Places
Coastal Environments: influenced & shaped by physical and human processes
Lithology Properties (rock); Geological Structure (concordant coastline = geological strata is parallel to the coastline, discordant = perpendicular);
Processes (erosion, deposition);
Sea-Level Changes (interact w/ processes, advancing/retreating coastlines);
Human Impacts;
Ecosystem Type
Waves: wind blowing over the sea surface, tides, or earthquakes (tsunamis); controlled by wind strength & duration, the distance of open water, & depth
Swell waves = open water, travel huge distances, long wavelength, reduced height; Storm waves: destructive waves, local winds, short distance.
Swash = movement of water up the beach (energy transferred to the shore); Backwash = movement of water down the beach, gravity.
Wave Refraction: approach an irregular coastline; refraction reduces wave velocity - wavefronts break parallel to the shore (if refraction is completed).
Concentrate energy onto sides of headlands and dissipate energy in bays
Sediment Supply: littoral cell system (coastal sediment system) - coastal processes & patterns in an area, simplified; input & output balanced.
Dynamic equilibrium: any system = inputs & processes w/in the cell; change in input affects processes & resulting change in landforms
Lithology: characteristics of rocks (resistance, bedding, jointing, permeability); well-developed jointing = cliff, wave erosion (finds weakness)
Composite cliff = more than one rock type; shape & form of cliff depends on strength and structure (impermeable versus permeable rock).
Subaerial and Wave Processes: operate on coastlines & produce landforms.
Weathering: Salt (sodium compounds expand joints), Freeze Thaw (water freezes & expands), Water Layer (tidal cycle), Biological (organisms).
Erosion: Abrasion (tiny particles), Hydraulic Impact (force of water), Solution (acidic water dissolves rock), Attrition (large rocks collide & erode)
Features of Erosion: bays (hard rock = headlands, weak rock = eroded to bays) ; Bayhead beaches = constructive waves, deposit sand b/w headland
Faults erode into sea caves; arch = two sea caves meet; stack = roof of arch collapse (further erodes into stump); energy of wave refraction
Wave-cut (shore) platforms: intertidal, high-tide, or low-tide; high-energy; cliffs eroded to lower-angle cliffs; subaerial processes
Cliffs: depend on geo. Structure and subaerial & marine processes; low resistance rocks = easily eroded, can’t support overhang.
Features of Deposition: requires a large supply of material, longshore drift, irregular coastline, low-energy, & bioconstruction.
Storm waves = winter, Swell waves = summer; destructive waves = reduced beach angle; small sediment = reduced impact of swash & backwash.
Spit: the beach of sand linked at one end to land; indented coastlines or river mouths; thin attached end (proximal end) & larger end (distal end).
Curved, waves undergo refraction; longshore drift = moves sediment along the coast, and irregular coastline = refraction (waves bend).
Beaches & Sand Dunes: large dunes = mid-latitude, storm waves (sand supply, high onshore wind speed, low precipitation & humidity)
The tidal range exposes sand (eroding rivers); free dunes (no vegetation, desert), embedded dunes (vegetation trap sand, humid areas)
Case Study: The Palisadoes, Jamaica; largest deposited coastal system in the Caribbean (13 km, 4000 yrs old)
Longshore drift = east to west provides sediments; located at a sharp bend in coastline (sediment carried westwards); extends the length of the spit
Spit grew longer and linked with small islands (cays); forming a tombolo; an area vulnerable to natural disasters (tropical storms & hurricanes)
Advancing and Retreating Coastlines: isostatic change = localized change in level of land relative to sea level; rise = tectonic uplift (remove ice)
Global warming (enhanced greenhouse effect) raises sea levels, impacts low-lying communities
Retreating = rate of erosion exceeds the rate of deposition (submerged coasts); Advancing = rapid deposition (emerging coasts).
Coastal Processes, Wind, & Vegetation in Sand Dune Development:
Sand moved by wind (up to 1 mm); grains above 1 mm = saltation (move by turbulence); irregular = inc. wind speed, more sediment moved
Shore = soil contains few nutrients, mostly sand, “yellow dunes”; vegetation needed for stable dune (dec. wind speed, deposition can keep up)
Reduce wind speed = less evapotranspiration loss (moist soil, decaying marram add nutrients to soil - more acidic)
Slack (low points b/w dunes) = moist conditions; marsh vegetation; rear of dune system = “grey dunes” - humus in soil
Many shells = calcium, form grasslands; calcium leached from old dunes = acid dunes (outwash of sand and gravel)
3. Managing Coastal Margins
Coastal Erosion and Flooding Management Strategies:
Human pressures = need for coastal management; prevent coastal erosion & flooding by sea; inc. pressure = inc. pop. & temp.
Defense options: do nothing, maintain existing defense, improve defense, manage retreat (protect some areas, let others erode)
Hard engineering = man-made techniques; Soft Engineering = working with nature to protect the coast (offshore reef, beach nourishment)
Cliff defenses: cliff base (sea walls, attempt to absorb the energy of waves, protect from erosion), cliff face (cliff drainage, make cliff less steep)
Norfolk, UK: Major energy development at the gas terminal at Bacton; protected by gabions & concrete blocks
Cost-Benefit Analysis of Coastal Defence: costs of building & maintenance, reduced beach access; protection buildings & rising land price.
New York: Superstorm Sandy in 2012; 14 ft storm surge; defences = 12 ft; $20 B in damages versus $19 B for new defecses
Fukushima-Daiichi tsunami: 2011; surges over 11 m; overt topped 10 m high sea walls
Case Study: Palisadoes spit; storm surges & coastal flooding led to erosion of dune; Jamaican gov. = repair degraded shoreline (cost $65 M).
Rock revetment walls, Caribbean; road - 1 m to 3.2 m above sea level; drainage facilities (excess water); 10 m boardwalk
Case Study: Thames Barrier; 1982, £500 M; protect London from flooding (flood risks rising - sea level rise & subsidence); used 7 times per year.
Conflicting Pressures on Coastlines: the Soufrière Marine Management Area (SMMA); 1995; stewardship resource management approach.
Conserve and protect the marine environment. & sustainable development (fishing & tourism); 11 km of coastline, 5 zones (cater to various uses)
Central west coast of the Caribbean island of St. Lucia; submarine shelf, supports reeds; fishermen competing w/ tourism-related users.
1980s: expand tourism sector; conflicts - inc. competition b/w fishers and yachters, use of fishing areas & reefs.
SMMA = new zoning plan (fishing priority areas, reserves, multiple-use areas); management measures (user fees, incentives).
1997: difficulties in implementing SMMA; involve stakeholders; inc. fish caught & fish biodiversity; less damage to coral reefs
Top-down approach (rules & regulations established w/o public consult); lack enforcement capabilities (limited financials) - SMMA helped
Beaches = target for illegal sand-mining; solid waste from land- and water-based sources; construction infrastructure (affect nature)
Managing Coral Reefs: 25% of species interact w/ coral; temp. above 18°C & below tropics, low acidity & sedimentation; water = 5-30 m
Biological & economic importance (tourism, Great Barrier Reef = $4.6 B); the global value of reefs (fishing, tourism & coastal protection) = $375 B
Advantages: biodiversity (breeding ground), seafood (LIC = 25% of fish catch), medicine (chem. from organisms, bone graft)
Coastal protection: reefs buffer adjacent shorelines from wave action & storm impact; maintain mangrove fisheries & wetland, support econ.
Pressures on coral: human activity (overfishing, tourism, pollution); greenhouse gasses - ocean acidification & coral bleaching
World Resources Institute: 60% of reefs = immediate threat (50 yrs to 2016 = lost 25% of corals); global conservation measures.
Marine Protected Areas (MPAs): status to eco. sensitive areas; restrict harmful activities; 10% of marine areas under conservation.
USA’s National Oceanic & Atmospheric Administration (NOAA); uses drones; to track fishing vessels & monitor temp.
Managing Mangrove Swamps: salt-tolerant forests; grow in tidal estuaries & coastal zones of tropical areas; muddy water = nutrient-rich.
25% of tropical coastline; provide food, fuel, materials, & med.; protect coastlines (absorb the force of storms); natural filters (absorb nutrients).
Pressures on mangroves: lost to rice paddles & shrimp farms; pop. growth in coastal areas inc.; Caribbean & S Pacific mangroves disappeared.
Overexploitation (Sabah = 40% of mangrove for wood ships); mangroves removed for urban expansion (rapid coastal development).
Integrated Coastal Zone Management (ICZM): developed due to pop. growth & mangrove destruction; sustainable use of mangroves.
1760: King José of Portugal, mangrove trees not cut for other uses; 1759: India, intensive management.
Restoration & Afforestation (plant mangrove trees); Managed Realignment (migrate inland); Flow Restoration (artificial flooding of wetland); Generic Protection (legislation to protect mangrove trees); Protected Area (1200 areas globally are protected, conservation/sustainability)
Sovereignty Right of Nations
Exclusive Economic Zone (EEZ): A coastal nation has sovereign rights over all economic resources of the sea, seabed, & soil
Extends up to 200 nautical miles from the coast; impact on the conservation of resources (can exploit, develop, & manage all resources).
90% of oil reserves & 98& of fishing regions under sea fall under a country’s EEZ
Ascension Island: the UK claimed ownership of 200 thousand km2 of Atlantic seabed surrounding Ascension Island.
Mountainous ocean floor up to 560 km from the island in S Atlantic = extensive mineral deposits (no near neighbours, no challenges).
Britain claims underwater territories around Rockall in N Atlantic (international interest in exploring seabed for scarce reserves).
Topic 4: Ocean Management Futures
Developing Abiotic Resources: natural resources found in the ocean (manganese, cobalt, copper, & nickel); difficult to gather (4 km of water)
1970s: industrial commodity prices higher & tech. Advanced; profitable to exploit minerals in ocean
2004: multiple countries were awarded licenses by the International Seabed Authority to explore mining possibilities on deep-ocean seabed
Nautilus Minerals (Canadian) = first deep-water mining company ; ore w/ copper & gold from Bismarck Sea (Papua New Guinea)
Hydrates: compounds of methane molecules trapped in water; found in permafrost (1960) & beneath ocean surface (1970)
Contain more energy than fossil fuel deposits; occur on fault lines; difficult to extract; methane traps more heat (global warming).
Oil: exploration = major activity in the Gulf of Mexico, South China, & North Sea; spills contaminated oceans; toxic effects on wildlife.
Threatens sea corals; hydrocarbons disorientate marine animals; shipping burns bunker oil - more CO2 & particulate matter.
2010: ban single-hulled ships; ban tributyltin (toxic chem. added to paint for ship hulls, kill algae & barnacles)
Case Study: Gulf of Mexico; 2010 = collapse of Deepwater Horizon oil rig; 4.9 M barrels of oil entered Gulf; 160 km of coastline affected
Attempt to plug the leak by pumping mud in a blowout preventer (unsuccessful, the force of oil upwards greater than mud)
Dispersants used to break up oil slick; order US gov. to limit use (prevent further damage to marine life in the Gulf of Mexico)
Topic 5: Environmental, Economic, & Geopolitical Consequences of Overfishing
World Fisheries: 2012 = 160 M tonnes of fish ($215 B); fish supply as food inc. since 1961 (inc. 3.2% per year); Asia = 67% of total consumption
China = 35% in 2010; Globally = feed 3 B ppl, 20% of animal protein; North-west Pacific & Western-central Pacific = largest catches
Fish Stocks: 2011 = global capture production is 93.7 M tonnes; 2012 = 86.6 M tonnes
Declining stocks: catch fewer predatory fish & more small fish further down the food chain; affect the marine ecosystem
70% of global stocks need management; code in the North Sea has declined 10% since 1970; boats from the EU fish in other oceans.
Illegal Fishing: 26 M tonnes ($ 23 B); Satellite Application Catapult = monitoring system, automatic identification system (AIS) from ships
Virtual watch room tracks vessels globally using AIS data; alert when the vessel enters prohibited waters & slows down to fishing speed
Strategies for European Fishing Industry: World Bank report = $50 B per year lost to poor management, inefficient, & overfishing globally
Fishing capacity & some vessels inc.; each boat has a greater capacity (tech.); investment in new tech. wasted (overcapacity)
Amount of fish caught stable since 2016; depleting of fish stocks (more effort to catch remaining fish)
Case Study: Grand Banks, Newfoundland; closed in 1992 to allow stocks to recover; fish numbers not yet recovered (still low)
Cod niche in ecosystem taken over by other species (shrimp & langoustines)
Aquaculture: raise fish commercially (food); fish hatchery releases juvenile fish into the wild (recreational fishing or supplement species)
1980 to 2010 = inc. by 8.8% per year; 2012 = 66 M tonnes ($140 B); vulnerable to disease & environmental conditions
China: 2012 = 40 M tonnes of food fish & 13.5 M tonnes of aquatic algae ; HICs = reduce aquaculture output (competition)
High tech. costs (use antibiotics to keep fish healthy & steroids to improve growth); breeding program cost; high output and efficiency
Farmed salmon = net loss of protein in global food supply; most production uses non-carnivorous fish species
Use other fish species to produce feed for salmon (deplete other fish species); disease spread from farmed salmon to wild stocks
Cause pollution (uneaten food, chemicals, waste); contaminate waters (organic debris & steroids)
Escape of fish affects wild fish gene pool (interbreed w/ wild pop. & reduce genetic diversity, introduce non-natural genetic variations)
Initiatives to Manage Oceanic Pollution: North Sea = 50% of litter from ships; 80% of litter is land-based; 250 000 kg of waste in North Sea
Marine litter causes economic damage (loss for coastal communities, tourism, shipping, & fishing); cost for EU to clean = €630 M per year
Radioactive Waste: 1958-1992 = Arctic Ocean, Soviet Union, 18 nuclear reactors (still contain fuel); nuclear power process & radioisotopes
Nuclear waste remains radioactive for decades; Fukushima Daiichi, Japan = carried across Northern Pacific towards Canada & USA
Plastic: 2006 = 18 000 plastic pieces per km2 of sea (most in central Pacific, 100 M tonnes suspended in jetstream); 90% carried from land
Takes decades to decompose or sink; affects wildlife (eaten by turtles); break up of plastic attracts toxins (conc. in tiny organisms)
Case Study: Great Pacific Garbage Patch (GPGP) - con. of marine pollution by ocean currents; slow-moving mass, N Pacific gyre ; 15 M km2
Currents = circular effect ; pulls debris from North America, Asia, & Hawaiian Island ; Midway Islands = coral reef, birds = plastic in system
Photodegradation of Plastic: split into smaller particles (still plastic) ; particles in GPGP = too small to see
Chinese Expansion in South China Sea: vital trade artery (30% of world trade passes) ; China threatening 70 years of naval supremacy in W Pacific.
2016: installed two launch batteries for surface-to-air missiles on Woody Island (Paracel archipelago) ; claimed right to self-defence facilities.
Paracels also claimed by Vietnam & Taiwan; China insists virtually all of the sea is theirs
Built over coral reefs in Spratly Islands (4 km2 for military use); artificial land on rocks & reefs, claimed by Philippines, Taiwan, & Vietnam
2030: South China Sea on trend to become a ‘Chinese Lake’; legal, diplomatic, & military approaches to moderate China’s behavior
Legal = Philippines brought UNCLOS (United Nations Convention of the Laws of the Sea) to show China’s historic claim
Diplomatically = China negotiates with ASEAN (Association of Southeast Asian Nations) members individually
Military = increase in defense spending in China; USA = only power capable of standing up against China
The USA: wants to turn two Pacific Islands into military training grounds (live fire exercise for 16 weeks per year); Tinian & Pagan (uninhabited)
Changes in the Arctic: sea ice disappearing; potential trade routes & access to oil and gas reserves
Case Study: Arctic ; Canada = year-round presence ; Denmark = prove detached part of Lomonosov Ridge = Greenland ; Russia = staked claim
2008: Canada, Denmark, Norway, Russia, & USA ; divide resources in Arctic Ocean (25% of undiscovered oil, 90 B barrels & natural gas)
2015: Arctic Frontiers conference; planktonic animals abundant (inc. fishing potential)
Environmental groups = ban military & mineral mining; 1982 UN Law of the Sea Convention = tangle of overlapping Arctic claims
El Niño: a reversal of the normal atmospheric circulation in the southern Pacific Ocean, beginning arm water and low pressure to the eastern Pacific, and cool water and high pressure to the western Pacific
Occurs once every 2-10 years and lasts 12-18 months
La Niña: intensification of normal atmospheric process
The cold current that flows from the east across the equatorial Pacific Ocean
Occurs when low pressure in the western Pacific becomes even lower
Hurricanes:
Hurricanes (Tropical Cyclones): low-pressure systems; high-intensity rainfall, strong winds, & heavy waves (flooding & mudslides).
Originate from moist, tropical seas; erratic path; winds spiral rapidly around the calm area (eye); pressure contrast = strong gale-force winds.
Move excess heat from low latitudes to higher latitudes; begin as small-scale tropical depressions (low pressure, warm air rises).
Sea = temp. above 27°C and a depth of 60 m; low-pressure area far from the equator (Coriolis force rotates rising air mass); unstable conditions.
Saffir-Simpson scale = assign hurricane to 1 of 5 categories of potential disaster; based on wind intensity; formed in Atlantic and Pacific
Case Study:
Typhoon Haiyan, Philippines
winds of 314 km/hr
10 000 ppl killed & buildings were destroyed
sea waters rise 6 m
World Food Programme = $2 million in aid
economic cost = $15 billion (many countries pledged aid)
vulnerable community (no savings)
Ocean Role and Acidification:
Ocean Acidification: freshwater = pH of 7 & surface seawater = 8.2 (dropped to 8.1) ; absorption of CO2 by oceans ; 0.1 difference = inc. of 30%
Absorbed 50% extra CO2 during the industrial age; anthropogenic causes (human actions); threatened species (fisheries & coral reefs).
30% of human-made carbon absorbed by oceans; reacts and turns into carbonic acid - reducing calcification of organisms (growth rate Dec. 14%).
Pacific coast = failure of commercial oyster; Great Barrier Reef = coral bleaching; Poles / high latitudes = shellfish (pteropod) reduction
Oceans as a Source and Store of Carbon Dioxide: largest CO2 sink (90% of carbon); carbon on ocean floor lifted (thermohaline circulation) = source.
Cold glacial phases = atmospheric CO2 decreased, stored in oceans ; Warm interglacials = CO2 released from oceans (inc. atmospheric CO2).
CO2 reservoirs = fossil fuels, atmosphere, & oceans ; carbon cycle (photosynthesis produce CO2 & released by volcanic activity, long timescale)
Features of Erosion: bays (hard rock = headlands, weak rock = eroded to bays) ; Bayhead beaches = constructive waves, deposit sand b/w headland
Faults erode into sea caves; arch = two sea caves meet; stack = roof of arch collapse (further erodes into stump); energy of wave refraction
Wave-cut (shore) platforms: intertidal, high-tide, or low-tide; high-energy; cliffs eroded to lower-angle cliffs; subaerial processes
Cliffs: depend on geo. Structure and subaerial & marine processes; low resistance rocks = easily eroded, can’t support overhang.
Features of Deposition: requires a large supply of material, longshore drift, irregular coastline, low-energy, & bioconstruction.
Storm waves = winter, Swell waves = summer; destructive waves = reduced beach angle; small sediment = reduced impact of swash & backwash.
Spit: the beach of sand linked at one end to land; indented coastlines or river mouths; thin attached end (proximal end) & larger end (distal end).
Curved, waves undergo refraction; longshore drift = moves sediment along the coast, and irregular coastline = refraction (waves bend).
Beaches & Sand Dunes: large dunes = mid-latitude, storm waves (sand supply, high onshore wind speed, low precipitation & humidity)
The tidal range exposes sand (eroding rivers); free dunes (no vegetation, desert), embedded dunes (vegetation trap sand, humid areas)
Case Study: The Palisadoes, Jamaica; largest deposited coastal system in the Caribbean (13 km, 4000 yrs old)
Longshore drift = east to west provides sediments; located at a sharp bend in coastline (sediment carried westwards); extends the length of the spit
Spit grew longer and linked with small islands (cays); forming a tombolo; an area vulnerable to natural disasters (tropical storms & hurricanes)
Advancing and Retreating Coastlines: isostatic change = localized change in level of land relative to sea level; rise = tectonic uplift (remove ice)
Global warming (enhanced greenhouse effect) raises sea levels, impacts low-lying communities
Retreating = rate of erosion exceeds the rate of deposition (submerged coasts); Advancing = rapid deposition (emerging coasts).
Coastal Processes, Wind, & Vegetation in Sand Dune Development:
Sand moved by wind (up to 1 mm); grains above 1 mm = saltation (move by turbulence); irregular = inc. wind speed, more sediment moved
Shore = soil contains few nutrients, mostly sand, “yellow dunes”; vegetation needed for stable dune (dec. wind speed, deposition can keep up)
Reduce wind speed = less evapotranspiration loss (moist soil, decaying marram add nutrients to soil - more acidic)
Slack (low points b/w dunes) = moist conditions; marsh vegetation; rear of dune system = “grey dunes” - humus in soil
Many shells = calcium, form grasslands; calcium leached from old dunes = acid dunes (outwash of sand and gravel)
cks
Cost-Benefit Analysis of Coastal Defence: costs of building & maintenance, reduced beach access; protection buildings & rising land price.
New York: Superstorm Sandy in 2012; 14 ft storm surge; defences = 12 ft; $20 B in damages versus $19 B for new defecses
Fukushima-Daiichi tsunami: 2011; surges over 11 m; overt topped 10 m high sea walls
Case Study: Palisadoes spit; storm surges & coastal flooding led to erosion of tourism & coastal protection) = $375 B
pansion (rapid coastal development).
Ital nation has sovereign rights over all economic resources of the sea, seabed, & so Bismarck Sea (Papua New Guinea)
Hydrates: compounds of methane molecules trapped in water; found in permafrost (1960) & beneath ocean surface (1970)
Contain more energy than fossil fuel deposits; occur on fault lines; difficult to extract; methane traps more heat (global warming).
Oil: exploration = major activity in the Gulf of Mexico, South China, & North Sea; spills contaminated oceans; toxic effects on wildlife.
Threatens sea corals; hydrocarbons disorientate marine animals; shipping burns bunker oil - more CO2 & particulate matter.
2010: ban single-hulled ships; ban tributyltin (toxic chem. added to paint for ship hulls, kill algae & barnacles)
Case Study: Gulf of Mexico; 2010 = collapse of Deepwater Horizon oil rig; 4.9 M barrels of oil entered Gulf; 160 km of coastline affected
Attempt to plug the leak by pumping mud in a blowout preventer (unsuccessful, the force of oil upwards greater than mud)
Dispersants used to break up oil slick; order US gov. to limit use (prevent further damage to marine life in the Gulf of Mexico)
hing speed
Extreme Environments
Characteristics of Extreme Environments
Extreme Environment: relatively inaccessible areas that tend to be viewed as inhospitable to human habitation, though they do provide opportunities for settlement and economic activity
Clod & high altitude environments
Polar, glacial, periglacial & high mountains in nontropical areas
Hot, arid environments
Hot deserts and semi-arid areas
Distribution of Extreme Environments
Cold and high altitude environments → uneven distribution
Northern hemisphere → periglacial belt
Located towards the north and south poles where insolation is low
Desert and Semi-Arid environment
Covers ⅓ of the earth's surface
Generally located around the tropics
Due to permanent high-pressure systems that limit rain formation
Reason for Distribution
Both environments
The angle of incidence: the angle at which light strikes the surface of the Earth
The greater the latitude, the less sunlight the area receives
Sun’s rays strike the surface at a lower angle near the polar
Atmospheric circulation
Hot air near the equations rises and moves toward the poles
At around 30 degrees latitude → air pushed downwards due to the Ferrel Cell’s Wind Circulation
Ferrel Cell’s Wind Circulation: Driven by temperature differences, cool polar air masses, and warm subtropical air masses converge, pushing each other upwards along their meeting line around 60 and 70 degrees north and south.
Creates high pressure in the tropics
Cold air at poles is very dense → dense → creates high pressure + low-temperature environments
Reflection and Scattering
Reflection: most of the heat that reaches the surface in polar areas is reflected into space due to the shiny surfaces of ice caps and snow
Scattering: there is a greater thickness of atmosphere near the polar than at the equator that the sun’s ray must penetrate → more energy is reflected and scattered
Due to location sun rays enter the atmosphere in polar areas at an oblique angle → gasses absorb more heat and light, so less reaches the surface
Length of Daylight Hours
On equator → length of days is the same throughout the year (day = 12 hours, night = 12 hours)
Further from equation → more variation
Summer → more daylight
Winter → night lasts longer
Cold Environments
Altitude
The higher in the troposphere (first layer of the atmosphere), the lower the temperature
Lapse Rate: the rate at which temperature drops
Caused by adiabatic cooling
Adiabatic Cooling: the cooling of an air parcel as it rises adiabatically in the atmosphere
Arid Environments
Offshore Currents
Many deserts are on the west coast where the water is cold
Winds blow parallel to the coasting & push surface water towards the sea
Cold water draws upwards (upwelling) to replace surface water
The air’s capacity to hold moisture is diminished
Rainshadow Effect
Rising air at the slope of the mountain towards the wind cools and loses moisture
Descending air on the other side of the mountains warms up → decreasing its relative humidity → causing it to be dry
Characteristics of Extreme Environments
Cold & High Altitude Environments
Climate
Low temperatures all year around
Mountain environments
a large amount of rainfall → due to relief rain
Low rainfall → rain shadow area
High diurnal temperature ranges → Underlying rock weakens due to extreme freezing
Can easily lead to avalanches
Relief
Steep and rocky terrain which is mostly inaccessible
Young mountains have steep gradients and weak rock structures
The area is a frequent risk for rockfall and mass movement
Slope Aspect: the direction that a slope faces
Northern hemisphere (most of highest mountains) → slopes face south
Get more sunshine for longer periods of time
Causes difference in vegetarian and land uses than northern aspect
Altitude and Biosphere
Mountain areas have vertical series of bands of vegetation
Altitude affects temperature
As animals need vegetation for food → distribution is also along the altitude zones parallel to vegetarian
The number of species declines with increasing altitude
Tectonic hazard
Tectonics uplifts → mountain ranges
Still ongoing → creates constant instability
Areas around are affected by earthquakes
Wealthy countries → build earthquake-proof structures
Desert and Arid Environments
Climate
Moist defects
Generally low amount of rainfall
Rainfall Variability
Very high for arid regions
Varies from year to year
Diurnal Fluctuations
Arid regions generally have a large diurnal temperature range
Deserts near the sea have a moderating effect
Seasonal Fluctuations
Equatorial deserts: little season changes in temperatures
Subtropical deserts & mid-latitude deserts: great variation between winter and summer temperatures, especially in high altitudes
Wind
Arid regions are typically windy
Sparse vegetation
More air movements
Lack of frictional drag from trees
Connection can also cause heavy winds
Sun heats the ground and dry air above, which expands and rises, with cooler air coming in to replace
Wind removes moist air → increases evapotranspiration
Flash floods
Normally deserts may have irregular flash floods
Challenges for Human Habitation
Cold and High-Altitude Environments
Cold Environment
Typically have unstable terrain
Waterlogged solid → deteriorates vegetation growth and causes solifluction → unpredictable terrain change
Solifluction: seasonal freeze-thaw action upon waterlogging topsoils which induces downslope movement
Difficult to source liquid water & insulated pipes to carry them
Short growing season → outsources food
Roads ice frequently
Frost heave can cause damage
Ice Heaves: sheets of ice that push against each other or the shoreline. They form when ice sheets expand due to rapid temperature fluctuations. Thermal expansion of the ice occurs when a rapid increase follows a period of very cold weather in temperature
High Altitude Environment
Have great diurnal temperature variations
Think and weak soil → no fertility for agriculture & harsh winds
Generally low rainfall
Steep topography → accommodating infrastructure and communication is difficult to build and maintain
Altitude increases → decrease in air density, water vapor → dehydration, carbon dioxide, and boiling point of water → difficult to cook
Frequent avalanches → destroy settlements
Desert and Arid Environments
Lack of water and precipitation
No freshwater → impossible to farm and maintain livestock
Use chemical weathering to achieve finer soil
Great diurnal temperature variations
extremely high during the day and extremely cold during the night
Extreme temperatures limit vegetation growth
Changing Distributions of Extreme Environments
Glacial advancements and retreats
Glacier: Slow-moving mass of ice formed by accumulation and compaction of snow on mountains or near poles
Although solid, behaves like thick liquid and flows at an extremely slow rate under gravity
Glacial system → balance of inputs (accumulation of snow, avalanches, debris, heat), storage (ice, meltwater, moraine), and outputs (losses due to ablation: melting, sublimation, evaporation)
Ablation: all methods by which the glacier can lose mass. In this zone, there is a net loss in mass when outputs are greater than inputs
If accumulation > ablation → glacier avances
If accumulation < ablation → glacier retreats
If accumulation = ablation → glacier is steady
Glacier will have a positive regime when supply is greater than loss → thicken and advance
Glacier will have a negative regime when wasting is greater than supply → thin out and retreat
Natural Desertification
Desertification: the process by which deserts expand into semi-arid areas or become more intense
Variations in rainfall/drought/increased aridity can cause deserts to expand or retrace
Physical Processes and Landscapes
Glacial Processes and Landscapes
Glacial erosion
Plucking
Occur at the base of the glacier
As ice moves, meltwater seeps into joints and freezes to the rock → ripped out when the glacier moves
Can be used for abrasion
Abrasion
Debris carried by the glacier scrapes and scratches the rock
Finer material will smooth out the rock → producing gently sloping landforms
Factors affecting glacial erosion
Relative hardness of particles and bedrock
Most effects abrasion: har particles + soft bedrock
Ice thickness
Greater the thickness → greater the vertical pressure → more effective abrasion
Basal water pressure
Basal water pressure may lift the glazier above the level of particles that the base, reducing the among of the brain
Sliding of basal ice
Faster the rate of basal slides → greater the rate of abrasion
Movement of debris towards the glacier base
If particles at the glacier base are not renewed → become polished → less abrasion
Debris particle size and shape
Large and angular debris abrade much more effectively than small and round debris
Landforms produced by glacial erosion
Cirque: an oval-shaped depression in the side with a steep back wall and a rock lip
Arete: narrow, knifed-edged ridge
Pyramidal peak: pointed peak with radiating aretes
Glacial trough: steep-sided u-shaped valley
Hanging valley: tributary glacier left high above the main valley
Truncated sur: steep cliff-like valley sides
Rock steps: stepped long profile in a glacial trough
Ribbon Lake: long narrow lack in glacial trough
Cirque lake: small, deep, circular lake
Roche Moutonné: ice-smoothed rocks with steeper side facing down-valley
Striations: rocks scaled with parallel scratches
Periglacial Processes and Landscapes
Freeze-thaw: the process by which the freezing of water puts pressure on rocks (especially jointed rocks). Only occurs when the temperature fluctuates above and below freezing points are there are cycle of strain and release
Mass Movement
Frost Heave: the expansion of fine-grained soils such as silts and clays to form small domes. Results from the direct formation of ice.
The thermal conductivity of stones is greater than spil so they are underneath the stone become colder → ice crystals form
The crystals force the stones above them to rise
Solifluction: Common when surface sediments are poorly drained and saturated with water. Occurs when tyres are above zero and free liquid water is available in the action later
In winter, water freezes in the soil, causing expansion and secretion of individual soil particles
In spring, the ice metals and water flows downhill
Water cannot filtrate the soil due to permafrost → flows over and caries the segregated soil particles and deposits them further down
Frost creep: type of solifluction that occurs because of frost heaving and thawing
Starts with the freezing of the surface ground, angling particles at right angles. As ice thaws in the warm season, contracting surface drops particles in elevation due to gravity → particles move slightly downslope
Rockfalls: occur when fragments of rock break away from a cliff face from freeze-thaw weathering
Periglacial Landscapes Features
Permafrost: permanently frozen subsurface
To be classified as permafrost must be frozen for at least 2 years
Commonly occurs in periglacial environments
Types of permafrost
Continuous
Discontinuous
Sporadic
Thermokarst: irregular, hummocky terrain with marshy or lake-filled hollows created by the disruption of permafrost's thermal equilibrium
Pingos: dome-shaped isolated killed with interrupt flat tundra plains. Form as a result of movement and freezing of water under pressure
Open-system pingos: forms when the source of water is a distance elevate the source
Closed-system pingos: forms when the supply of water is local and permafrost expands
Often form on site of small lakes where water is trapped by freezing from above
Physical Processes in Hot Arid Environments
Mechanical weathering
Salt crystallization: a form of weathering which causes the decomposition of rock by the solution of salt, causing chemical and physical changes in the rock
Disintegration: a form of weathering where the grains of rock become loose and fall out, leaving a pitted surface
Occurs in deserts with lar diurnal temperature ranges
Erosion
Water
Exogenous rivers: rivers that have their source in wetter environments and then flow through a desert
Endorheic Rivers: rivers that drain into an inland lake or sea
Ephemeral rivers: Rivers that flow seasonally or after a storm and tend to have high discharges and sediment levels
Wind
The movement of sediment is crashed by drag and lift forces, also known as suspension, but are reduced by particle size and friction
Deflation: Progressive removal of fine material by the wind leaving behind larger materials
Abrasion: sandblasting action acted by materials as they are moved by alteration
Saltation bouncing of sand particles by wind forces
The process smooths away rock close to the ground
Landscape features in hot arid environments
Formed by deposition
Dunes: develops when sans Grania, moved by saltation and surface creep, are deposited
Form around large rocks, which hold the main part of the dune in place
Formed by wind erosion
Yardangs: extensive ridges of rock. They are separated by troughs, and have an alignment similar to the prevailing winds.
The strata are vertical
Zeugens: tabular masses of resistant rock separated by trenches where the wind cuts vertically through the cap into the underlying soft rock
The strata are horizontal
Rock petals: formed by exposed isolated rocks in the series when a more resistant layer of sedimentary rocks sits above a softer layer
The lower softer rock erodes faster than the higher, more resistance-rich
Oases: fertile spots in the desert where water is found. Formed where natural depressions are deep enough to cut into water table
This leads to semi-permanent water is available near the surface
Formed by water erosion
Wadis: dry river channels that are generally steep-sided and flat-bottomed. May have formed during flash floods or during wetter pluvial periods in the Ice Age when the runoff collected from sheet flood becomes concentrated into deep ravines
Measea: Plateau-like featured with steep-sides
As the mesa is reduced in size by cliff retreats, it rains its flat top and altitude
Buttles: a smaller version of mesas, representing the final stage of erosion before the resistance rock is finally eroded
Managing the Future of the Environment
Agriculture in Arid Areas
Benefits: The environment offers an abundance of heat and sunlight, favoring a lengthy growing season. If water is available, farming can be an opportunity. Opportunities include:
Nomadism
Settled farming with groundwater
Irrigation next to rivers and oasses
Increased use of drought-tolerant species
Challenges and possible solutions: The area is dominated by the lack of fresh water, too much sunlight and heat, low rainfall seasons, alien waters, strong dry winds, poor soil structure, overgrazing, and poor transport. All arid and semi-arid have negative water balance (outputs from evapotranspiration and stores of water exceed this input from precipitation
Soil is arid due to low rainfall and high evapotranspiration
Soil is infertile due to:
Low organic content
Generally thin with few minerals
Lack of clay
Soluble salts in soil which can be toxic to plants
Irrigation access
Not all areas have access to irrigation
To the areas that do, problems include salinization, depletion of groundwater, pollution, and less access to water elsewhere
Salinisation Risk
May occur in areas where the water table is close to the surface & annual precipitation is less than 250 mm
In poor drainage locations (ex. Valleys and basins), surface water evaporates and leaves behind large amounts of salts
Saline soils adversely affect the growth of more crops
Reduces rate of water uptake by roots
Sustainability
Agriculture in arid and semi-arid environments can be made more sustainable by:
Reducing her size and pressure on the amount of limited vegetation
Use solar panels to produce energy
Plant vegetation
Use more efficient types of irrigation
Building check dams to collect water
Using more salt-tolerant plants
Mineral extraction
In extreme environments: opens up opportunities for poorly developed regions, employ opportunities, and can generate significant income from exports
In cold environments: resource development can improve, but can put the environment under pressure and create conflict
Due to inaccessible, there is a high cost of attracting workers
Fragility Of periglacial areas
The limited ecosystem is highly susceptible to interference
Low temperature limits decomposition, which can lead to pollution (especially oil)
Frost heave
Can lift piles for oil pipelines and structure out of the ground → need to be embedded deeper which is expensive
Resource nationalism
Governments tend to assert control of natural resources in their territory and conflict with the interest of multinational corporations
In arid environments: huge potential for development and generate large earnings for countries that develop them
Due to inaccessibility, there is a high cost of attracting workers and protecting people from extreme heat and aridity
Politics
Risk of intruding on rights of Indigenous people
Environmental impact
The movement of people and vehicles can introduce exotic species
Mines can be a major source of dust pollution linked to respiratory disease
Open-pit mining can expose dangerous chemicals and contaminated groundwater
Tourism in Extreme Environments
Cold Environments
Popular destinations due to scenery, rare species, pristine landscapes
Mountain environments have a low carrying capacity and are easily damaged by human impact because of this erodible soil and vegetation
Arid Environments
tourism opportunities may be linked to scenery, wildlife, indigenous culture and outdoor pursuits.
create jobs, provide income for workers,
Challenges include extremes of temperature, accessibility, water shortages and a lack of resources to sustain tourism.
The impacts on the natural environment include mass movement, erosion, land degradation, hazards, aesthetic changes, water shortages, waste, introduction of exotic species and habitat removal.
Future of Extreme Environments
Desertification
Desertification: Land degradation in humid and semi-arid areas (not including non-desert (arid) areas)
Involves the loss of biological and economic productivity and it occurs where climatic variability (especially rainfall) coincides with unsustainable human activities.
Causes
Desertification can be a natural process intensified by human activities. All areas affected by desertification are marginal and have highly variable rainfall, except rainforests desertified by inappropriate farming techniques.
Natural causes
Temporary drought periods of high magnitude and long-term climate change towards aridity.
Overgrazing
Vegetation is lost through grazing and trampling by large numbers of livestock.
Overgrazed lands become more vulnerable to erosion as compaction of the soils reduces infiltration (increasing surface runoff) and trampling increases wind erosion.
Fencing leads to severe localized overgrazing while boreholes and wells cover the water table, leading to soil salinization.
Overcultivation
This leads to diminishing returns (yield decreases every season) and so to maintain the return on agricultural investment, the area of growth must be expanded.
Reducing fallow periods and introducing irrigation help to maintain output, but contribute to further soil degradation and erosion by lowering soil fertility and promoting salinisation.
Deforestation
Occurs where land has been cleared to extend the area of cultivation and in the surrounds of urban areas for firewood.
The loss of vegetation cover increases rainsplash erosion and the absence of root systems allows for easy soil removal by wind and water.
Climate change
Soils exposed to degradation as a result of poor land management could become infertile as a result of climate change.
Climate change may exacerbate desertification through alteration of spatial and temporal patterns in temperature, rainfall, solar radiation and winds.
Access to Resources In Extreme Environments
Arctic region
As ice caps are melting, a military race between the US and Russia competing for its extremely valuable resources
The region is opening up two major shipping lanes, and oil and gas reserves are worth trillions of dollars.
If the Arctic region continues to melt and open up vital shipping lanes, there must be international cooperation to provide security and rescue elements for commercial shipping.
Oil conflicts in the Middle East
Conflicts over oil are the result of long-standing historical disputes, which have developed into the desire to control valuable oil and natural gas assets.
The economic world has become energy-centric, and access to energy resources provides strength and power for some countries, whereas lack of resources leads to vulnerability for other countries.
Countries with surplus energy reserves, and the ability to export energy, often have a disproportionate influence on the world stage.
ISIS: A Sunni extremist group that controls large parts of western Syria and northern Iraq. ISIS controls key oil-producing areas of Syria and oil-refining facilities in Iraq. This, in part, allows it to pay for its military. Such conflicts make it difficult for countries that depend on Middle Eastern oil.
Sustainable development: New technology and sustainable developments in extreme environments
Sustainable development: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs. They should fulfil needs, in particular the essential needs of the world's poor, but are restricted by limitations imposed by the state of technology and social organization on the environment's ability to meet these present and future needs.
Solar power
A completely renewable resource which has non-direct pollution during electricity generation and requires little maintenance.
However, there are high initial costs for solar plants and it is limited in that power cannot be harnessed at night or in countries with low annual hours of sunlight
Desalination
The removal of salts and minerals from seawater and soil.
Due to high energy input, the costs of desalinating seawater are generally higher than the alternatives, but alternatives are only sometimes available and depletion of reserves is a problem in certain locations.
The main criticism regarding desalination and the use of reverse-osmosis technology is that it costs too much.
Aquaponics
An integrated form of farming that enables farmers to increase yields by growing plants and farming fish in the same closed freshwater system.
Mimics natural processes and enables waste to be efficiently reused.
Climate change and EEs
The impacts and management of global climate change in extreme environments, including adaptation by local populations
Climate change impacts on arid environments:
Food security
As temperatures rise, evaporation levels will increase and reduce precipitation effectiveness.
Environmental hazards such as floods and droughts will become more common in arid areas like the Sahel, disrupting agricultural systems
reduce food production and availability and increase prices, food insecurity and hunger.
Poverty will exacerbate the impacts of climate change in these areas.
Local adaptation strategies by Senegal:
Improving soil fertility by the careful use of fertilizers
Improving the efficiency of irrigation systems and pest control
Adopting water and soil conservation techniques using baguettes (stone rows) to reduce run-off on slopes
Developing the Great Green Wall of the Sahara and the Sahel Initiative (GGWSSI), that is, a massive line of trees across the southern Sahara and Sahel to combat the combined effect of resource degradation (deforestation and soil erosion) and drought/desertification
Coping strategies for water shortages
Adaptations to water shortages include:
Increased mobility (the traditional way)
Management of size and composition of herds
Exchange of livestock and livestock products
Increased use of drought-tolerant species
Utilization of wild species and tree crops
Windbreaks to reduce wind erosion of bare soil
Irrigating with silt-laden river water to restore soil
Dune stabilization using straw bales and xerophytic plants
Land enclosure to reduce wind erosion
Climate change impacts on cold environments
Any increase in temperature is likely to have a greater impact in areas where the mean annual temperature is only a little below the freezing point.
risk of degradation and the development of thermokarst (subsidence).
Benefits
The warming climate has made minerals that were once locked in ice accessible.
Farming may become more productive as net primary productivity increases and the length of the growing season increases.
Consequences
Many settlements are located at river mouths, river confluences or islands.
Melting permafrost, coastal erosion, increased flooding and a rise in sea level due to climate change will take a toll on buildings, ports, bridges and roads.
This will increase the number of climate refugees as well as death tolls from unpredictable sea ice.
life in cold extreme environments will become more expensive (e.g. snowmobiles must take longer routes, and buildings are weakened by melting permafrost).
People relying on fishing will either have to go further to catch or alter to take into account changes in species composition.
Hazards and Disasters-Risk Assessment and Response
1. What determines the severity of a hazard?
Duration:
The length of time that a hazard lasts.
As a general rule the longer the hazard the more severe it is likely to be.
Example: an earthquake that lasts 1 minute is likely more severe than one that lasts two seconds and a drought that lasts ten years is likely more severe than one that lasts three months.
Magnitude:
This is the strength of a hazard.
Most hazards are measured on a scale
Example: the Richter scale or the volcanic explosivity index (VEI).
Generally speaking, the stronger the hazard the more severe the hazard is.
Predictability:
Some hazards are easier to predict than others.
Example, volcanoes normally give warning signs before they erupt and tropical storms can be tracked from development to landfall.
However, others like earthquakes are much harder to predict.
Generally speaking, hazards that hit with no warning will be more serious.
Regularity:
If hazards happen often and in quick succession
Example: an earthquake followed by multiple aftershocks then the severity is likely to be greater.
During hurricane seasons, countries can be hit by repeated storms each causing greater damage because it has not been possible to recover from previous damage.
Frequency:
The return interval of hazards of certain sizes.
Example, earthquakes with a magnitude of over 8.0 happen on average once
If the hazard is a less frequent strong event, then it is going to have a bigger impact.
Speed of onset:
If the peak of the hazard arrives first or arrives quickly
Example: an earthquake, then the affects are likely to be worse than one that arrives slowly
Example: a drought.
Spatial concentration:
Where hazards are located or centred.
Example: earthquakes tend to be focused along plate boundaries, whereas tropical storms tend to be located in coastal areas in the tropics.
Hazards that are located in known areas can be better prepared for and managed better.
Areal extent:
If a hazard covers a large area
Example: a drought covering the whole of East Africa, then the severity of the hazard is likely to be more severe, than a flood hitting just one village.
The number of hazards:
If multiple hazards hit a location the effects can be more severe.
Example: hazard hotspots like Indonesia can be hit by earthquakes, volcanoes, landslides and flooding all simultaneously.
2. Predicting Earthquakes
Scientists can attempt to predict by looking at:
Microearthquakes
Changes in rock stress
Ground subsidence, uplift or tilt
Changes in magnetic field and electrical resistivity of rocks
Animal behavior
Seismic history
3. Factors Affecting the Impact of Earthquakes:
Depth: If the hypocentre of an earthquake is close to the surface then it is more likely to cause greater damage than a deep earthquake.
Duration: A longer earthquake is likely to cause greater damage than an earthquake that lasts only a few seconds.
Magnitude: A stronger earthquake is going to have a greater impact than a weaker one.
Time of Day: Time of day can be important. If people are sleeping and get trapped in their beds more people can be killed. In Japan, an earthquake that struck while people were cooking their evening dinner caused widespread secondary hazards (fire) that caused more deaths.
Epicentre Location: If the epicentre of an earthquake is an uninhabited region it is going to have a lesser effect than one under a densely populated city.
Geology: If an earthquake occurs in solid bedrock it is likely to cause less damage than one centred below an alluvial floodplain which may lead to liquefaction.
Economic Development (buildings, planning, preparedness): Generally more developed countries have better zonal planning, building codes and preparedness meaning the effects of the earthquake are less.
4. Hurricanes
Hurricanes are normally measured by using the Saffir-Simpson Hurricane Scale developed by the National Oceanic and Atmospheric Administration.
Hurricanes are measured on a scale of 1-5 depending on their wind speed and storm surge.
Category five storms only sometimes cause the most damage.
The amount of damage caused by hurricanes can depend on several factors including:
Where landfall is (populated or non-populated area)
The development of the country
The warning given to residents and the preparedness of residents.
The existing conditions (saturated ground or not)
5. Drought
Studies conducted over the past century have shown that meteorological drought is never the result of a single cause.
It is the result of many causes.
Scientists don’t know how to predict drought a month or more in advance for most locations.
Predicting drought depends on the ability to forecast two fundamental meteorological surface parameters, precipitation and temperature.
From the historical record, we know that climate is inherently variable.
We also know that anomalies of precipitation and temperature may last from several months to several decades.
How long they last depends on air–sea interactions, soil moisture and land surface processes, topography, internal dynamics, and the accumulated influence of dynamically unstable synoptic weather systems at the global scale.
Meteorologists have made significant advances in understanding the climate system.
It may now be possible to predict certain climatic conditions associated with ENSO (El Nino) events more than a year in advance.
For those regions whose climate is greatly influenced by ENSO events meteorological forecasts can reduce risks in those economic sectors (mainly agriculture) most sensitive to climate variability and, particularly, extreme events such as drought.
Droughts endanger lives and livelihoods through thirst, hunger (due to crops dying from lack of water) and the spread of disease.
Millions of people died in the 20th century due to severe drought and famines.
One of the worst hit areas was the Sahel region of Africa, which covers parts of Eritrea, Ethiopia and the Sudan.
Droughts and famines can have other geographical impacts.
If drought forces people to migrate to a new home it could put pressure on resources in neighbouring countries.
Droughts can have a severe impact on MEDCs as well as LEDCs.
Droughts have caused deaths in Europe in recent years - especially among the elderly.
In the UK in the summer of 2006, there were hose-pipe bans and campaigns to make people save water.
6. What factors influence our risk perception?
Is the risk voluntary? Professional soldiers for example will perceive the risk of being shot differently from a civilian.
Time scale: people perceive immediate impacts of a hazard as more severe and 'real' than long-term ones. In an earthquake for example the risk of a building falling on you is more feared than the long-term risk to your health.
Psychological perception: certain hazards create a very intense fear response in humans for example the fear of fire and any hazard that might cause this will be perceived as worse than an avalanche.
Understanding/Knowledge: We fear what we do not know much about or we fear it less due to a limited understanding of the true risk.
Media: Certain hazards are widely publicised and covered in the international media. This can colour our perception of risk.
For a disaster to be entered into the database of the UN's ISDR (International Strategy for Disaster Reduction), at least one of the following criteria must be met:
A report of 10 or more people killed
A report of 100 people affected
A declaration of a state of emergency by the relevant government
A request by the national government for international assistance
7. Methods available to dealing with hazards:
Preparation:
Governments might consider how they can educate and prepare their populations for a disaster so that they know what to do in a hazardous event.
Also, governments can put into place laws and building codes to govern what can be built and to what standard, so that hazard impacts from hurricanes, earthquakes etc can be reduced.
Prediction:
This is the mechanism by which we try to forecast when and where a hazard will occur.
There are a huge range of prediction methods now for a huge range of hazards, think about the Avalanche risk charts you may have seen whilst skiing.
We can use satellites, river flow meters, sulphur dioxide meters, tilt meters etc to predict different hazards.
We are better at predicting some hazards such as flooding, than we are others, such as earthquakes, because some of the warning signs are clearer and because of the amount of response time to each hazard.
Prevention:
These are the methods that we can put into place as human beings to either prevent the hazard entirely or prevent some of the negative impacts of a hazard.
Some hazards such as forest fires can be prevented, by using fire breaks and prescribed (deliberate fires) major forest fires can be stopped.
Other hazards cannot be prevented, such as Hurricanes.
However, we can prevent some of the flooding during hurricanes by having correct drainage systems and coastal defences.
8. Reducing Vulnerability - Preparation
Aid:
Aid can be used as an adjustment before potential hazards strike or after hazards strike.
Aid before hazards strike will take the form of development aid and may include:
The building of wells to reduce drought and disease
The improvement of irrigation and the introduction of GM crops to reduce famine
The building of dams to reduce the risk of flooding and droughts
The building of roads and mobile networks to improve transport and communication throughout a country
The building of schools to improve education about hazards
The building of hospitals to reduce hazards like disease and treat people injured in hazards
Aid given after a hazard or during a hazard is more emergency aid. Emergency aid may include:
The sending of rescue teams to search for victims
The provision of medicine or doctors to help injured
The provision of food and clean water
The provision of tents and blankets, etc.
Aid may also be given later to help rebuild after a disaster
Example: rebuilding homes, roads, schools, hospitals and electricity supply.
Insurance:
Insurance is the act of insuring (protecting) property, people, businesses, etc. against the risk of something happening.
Example: a person dying or being injured, or property being flooded or burnt down
To insure something it is necessary to pay a premium appropriate to the likelihood of something happening
Example: an 80-year-old person is likely to die fairly soon, so any premium will be high, but the likelihood of a 25-year-old dying shortly is much less so the insurance premium will be much less
Normally insurance policies are taken out with private companies, but if the risk of insuring is too high, then private companies may refuse insurance.
In these circumstances, governments will sometimes offer insurance.
Hazard Mapping (Land use planning or zoning)
Hazard maps are created by calculating the vulnerability of different areas to natural hazards.
Hazard maps are often made to calculate populations’ vulnerability to hazards like earthquakes, hurricanes, volcanoes and floods.
Once potential hazards are known then appropriate adjustments can be taken.
Adjustments may include:
Creating zones where building is not permitted because it is too dangerous
Creating zones where only low-value uses are permitted
Example: farming
Protecting areas that are vulnerable to hazards with the use of defences
Evacuating vulnerable areas (and possibly allowing managed retreat in coastal areas)
Rebuilding vulnerable areas to new building standards
When creating a hazard map several variables will be considered.
Example: scientists creating an earthquake hazard map will look at the following:
Proximity to plate boundary or known fault
Seismic history (frequency and magnitude)
Geology (bedrock is much more stable than alluvial deposits which are vulnerable to liquefaction)
Gradient (flatter ground is generally more stable than steep land)
Possible secondary hazards (proximity to the coast for things like tsunamis, but also hills for landslides (forested/deforested))
9. Responses to a Hazard:
Short-term response:
A response in the days and weeks immediately after a disaster.
Short-term responses mainly involve search and rescue and helping the injured.
Mid-term response:
Responses in the weeks and months following a disaster.
Mid-term responses involve re-opening transport links and getting electricity and water supplies operational again.
It might also involve establishing longer-term refugee camps where there has been large-scale destruction.
Long-term response:
Responses that go on for months and years after a disaster.
It involves rebuilding destroyed houses, schools, hospitals, etc.
It also involves kick-starting the local economy.
Leisure, Sport, and Tourism
1. Changing leisure patterns
Reasons for the increase in leisure time:
Increase in disposable income
refers to the income that is available to a person after tax
In most countries, disposable income has increased
allows people to save a significant percentage of their income for leisure or tourism
in some organizations, 10% of their income is saved and given to them at the end of the year for them to embark on tourism
Increase in advertisement
made it possible for people to know where they can visit for tourism
CNN advertises Malaysia, Azerbaijan, Turkey etc
Inflight advertisements showing places you can visit upon arrival at your destination
increase people’s chances of visiting tourist centres in the country of destination.
Transportation improvement
Improved air, sea and land transport has made it easier and possible to reach many tourist destinations
the world’s fastest aircraft, the Concorde, was twice faster than the speed of sound
high-speed trains that can travel about 300km per hour
shortened the distance between places, thus allowing people to embark on journeys at a much faster rate
Large cruise ships also promote packaged tours to places such as Venice in Italy or other Caribbean islands
contributing to people’s chances of engaging in tourism
Cheaper cost of transportation
Cheaper airfares and cheaper costs of travel by sea have also contributed to reducing the cost of travel
the large passenger plane, Airbus A320 can carry over 400 passengers at a time
many passengers would mean lower airfare per passenger
More leisure time for most workers
teachers have 13 weeks of holidays so they can decide to go anywhere they want
Reduction in the number of working days and hours for some workers in government institutions in some countries
Paid leaves
Early retirement
Development in technology
People spend less time on house chores, hence more time for leisure
Categorization of tourism and sporting activities
Sport:
Group 1- Athletics and Rugby (Archery, American football, Lacrosse, Gymnastics)
Group 2- Dancing and Yoga (aerobics, Pilates)
Group 3- Outdoor sports (fishing, cycling)
Group 4- Swimming, Cycling and gym
Group 5- Racquet sports and running. (Badminton)
Group 6- Bowing
Group 7- Cricket, football, pub sports
Tourism:
Primary tourist/recreational resources – the pre‑existing attractions for tourism or recreation (that is, those not built specifically for the purpose), including climate, scenery, wildlife, indigenous people, cultural and heritage sites
Secondary tourist/recreational resources, which include accommodation, catering, entertainment and shopping.
Ecotourism—tourism focusing on the natural environment and local communities
Heritage tourism—tourism based on a historic legacy (landscape feature, historic building or event) as its major attraction
Sustainable tourism—tourism that conserves primary tourist resources and supports the livelihoods and culture of local people
Mass tourism
Medical tourism
Adventure tourism
Niche tourism
Sex tourism
2. Tourism and sport at the local and national scale
Factors that determine whether the area is a hotspot include:
Climate:
If the area has extreme temperatures, it may not serve as a hotspot, unless there is a special event which requires extremely high temperatures, such as the annual desert race that takes place in the Sahara.
If the area is too cold, then it could serve as a skiing hotspot ( such as in the Alps).
The culture of an area:
If the people have some type of religion (Mecca or Jerusalem), cuisine, clothing (Kente or Bonwire), architecture or education (Oxford, Cambridge) then people would go there to view these things.
Example: Mecca is a hotspot for Islamic pilgrims who visit the Holy Site as a form of religious worship. Jerusalem and the Holy Sites also serve as a hotspot for Christian pilgrimage.
Natural Landscape:
If it is low-lying, it would be adequate for football, rugby, golf etc.
If it is mountainous and cold, it would be adequate for skiing or an attractive area for biodiversity (Mount Verde cloud forest) or paragliding, or hiking.
Sporting Events:
If the area has sporting events, then it is more likely to attract tourists.
Countries such as Barcelona are well known for football, thus people are willing to travel to Barcelona just to watch their football matches.
World Cup events- whenever a country is hosting the World Cup, they see an influx in the number of tourists.
Olympic Events- whenever a country is hosting the Olympics, they also witness an influx in the number of tourists.
Government Investment and Planning:
The government deliberately makes tourism a key aspect of its economic development.
They focus more on providing both primary and secondary resources to attract tourists and this makes such places hotspots for tourism.
Examples: Dubai, Saudi Arabia, and The Maldives.
In the case of Dubai, they believe that in the next few years, their oil reserves will run out.
Thus to maintain the level of economic growth, they decided to deliberately invest in tourism.
Factors influencing the sphere influence of different kinds of sporting and tourist facilities
Affluence:
If the citizens are high-income earners, they can afford to patronise sporting events through stadium attendance, television views, souvenirs etc.
And are more likely to support through these means.
Government and Private Investment:
Government investment in infrastructure to support sports development, meant to attract young people to a sporting event, is more likely to attract many teams from such cities or countries.
China, for example, is investing heavily in football infrastructure.
Growth in popularity:
Well-known sports have a higher sphere of influence than sports that are not well-known.
Advertisement and marketing in new areas:
When a football club advertises its souvenirs and events in new areas, it increases its supporter base, hence its sphere of influence.
Also, rich clubs like Manchester City or Man U, Chelsea etc have been known to tour places such as China and the United States to play games and market merchandise.
Increased wealth and development in the country:
The country can invest in infrastructure that will attract more people to the country
The impact of global competition:
If the clubs play or compete at international levels, their sphere of influence increases
Increased exposure to different media as a result of an increase in technology:
The media in the form of TV, radio and the internet can beam live matches to a large number of viewers all over the world.
This increases the sphere of influence of the sport. Sports such as Football, tennis etc.
Greater population mobility.
Certain factors affect the location of teams and the distribution of supporters:
Population density:
The population is important because it is the people in the settlement that will patronize the club to enable them to get revenue and run the club
The level of income of the residence:
Clubs are usually located in places where fans have a reasonable level of income to be able to buy the tickets to support the clubs
The demographic composition of the population:
Certain sports are located in areas that require a certain age bracket of supporters.
A good example is soccer which requires a largely youthful and working population rather than an aging population while golf requires a larger working and ageing population.
The presence of certain physical activities (topography):
The topography or landscape will determine the location of certain sports or teams.
Example: beach soccer can only be played in coastal areas
The level of infrastructure in the area:
The road networks, stadiums, airports and anything that facilitates the movement of people to and from the area determines the location of a sports team
When the town is politically stable, teams will be located in the area since the teams need peace to thrive.
Government and private investment in infrastructure to support sports development that is meant to attract young people to a sporting event are more likely to encourage teams to emerge from sub-cities or towns.
Cultural and historical factors:
If a country is noted for competing in an event, it will tend to have a large number of clubs.
Example: England has long been noted as a soccer country
Proximity to competing teams:
The essence of being a sporting team is to compete with others for a grand prize.
As such, teams would be located in towns that have other teams.
This reduces the cost of travel, as the teams do not have to go over long distances to play with others.
In Ghana, for instance, the Kpando Hearts of Lions, the only team in the Volta Region migrated to Accra.
3. Tourism and sport at the international scale
Niche tourism strategies
Adventure tourism:
the tourists travel to remote areas or physically challenging environments that are sometimes dangerous to the tourists
Examples:
Travels to Mt Everest, Nepal
Visit to Antarctica
Sahara Tour
Mariana Trench
Extreme environment tourism:
involves dangerous landscapes often with a difficult climate, and remote places that are sparsely settled or not occupied at all
Characteristics of extreme tourists are that they are without children, have high-paid jobs/good income earners etc.
Movie location tourism:
takes place in areas where popular movies have been shot
Examples:
Lord of the Rings acted in New Zealand
Game of Thrones in Northern Ireland
The Hobbit in New Zealand
Theme parks such as Disneyland have created a setting that looks like the movie to attract viewers
Heritage tourism:
travel to experience the place, artifacts, historic sites or indigenous people
sometimes referred to as historical tourism.
Advantages of Niche tourism:
It is environmentally friendly, as it causes less pollution due to the limited number of people involved
It benefits the local population
Tourists can maximize the benefits of their tourist experience
Disadvantages:
It can be dangerous because it sometimes involves extreme and risky activities
It can be expensive
They are more likely to be exposed to various attacks by criminals
Advantages of Mass Tourism:
Travel in large groups thus it is safer.
It is cheaper because the cost is shared among everyone.
It boosts socialization because the tourists travel with people they are familiar with
It is well organised.
Disadvantages:
It is expensive in the long term because some travel and tourism agencies take advantage of the tourists.
Tourists are sometimes forced to visit places they might not want to visit.
It may lead to environmental degradation: noise pollution, water pollution, air pollution etc
Mass tourism may sometimes lead to terrorist attacks.
Economic benefits of tourism to SIDS
Increases the GDP of a country directly and indirectly through the ‘multiplier’ effect.
Multiplier effect: this means that the revenue obtained from the tourism industry could benefit other industries which could yield further income in other industries.
Taxes increase government revenue.
The government obtains tax from the tourists which can be used to invest in other projects in the country such as schools.
Increase the foreign exchange earnings of a country.
This can help to stabilise the country’s currency.
Can be used to import technology and machinery, and invest in other industries through foreign direct investment.
Creates employment for the local people.
Economic costs
This may divert government attention from needy areas of the economy such as education and health.
Requires government expenditure on tourism: The government would have to spend a lot of money providing good roads etc.
Profits may go overseas – In the form of ‘leakage’.
Leakage: when the profit is taken outside the country.
The spread effect is limited and may therefore cause regional inequalities.
It may only bring about regional development and not national development.
Inflates prices for land, housing, food and clothing.
Social benefits
May enhance the role and status of women in society.
How foreigners behave with their wives would usually influence how people in, for instance, LICs would treat their wives.
Encourages female education.
Saves the indigenous culture of the people due to tourist interest in them.
Increases international understanding of diverse cultures.
Culture exchanges stimulate broadening horizons.
Social costs
The breakdown of traditional family values creates a materialistic society.
Social pathology, including an increase in prostitution, drug use and petty crime.
Mass tourism may lead to resentment from the host population
Westernization of culture may lead to the depletion of the cultural heritage of the local people.
Environmental benefits
Improvement in landscape and architectural standards
The establishment of nature reserves and national parks protects the environment.
Promotes interest in monuments and historic sites which encourages preservation and maintenance of the sites.
Environmental costs
Tourist complexes do not reflect local architecture
The natural environment and wildlife habitat could be destroyed to allow for the development of secondary tourist facilities such as hotels, nightclubs etc.
Excessive pressure leads to air, noise and visual pollution
Traffic congestion and pollution
4. Managing tourism and sport for the future
Four types of carrying capacities:
Environmental/physical carrying capacity limit of a site beyond which wear and tear will start taking place or environmental problems will arise.
Perceptual / Psychological carrying capacity –The lowest degree of enjoyment tourists are prepared to accept before they start seeking alternative destinations.
Economic carrying capacity –The ability of a tourist site to absorb tourism activities without displacing or disrupting desirable local activities.
Social carrying capacity –The level of tolerance of the host population for the presence and behaviour of tourists in the destination area, and/or the degree of crowding users (tourists) are prepared to accept by others (other tourists).
Factors affecting carrying capacity in a tourist destination:
The fragility of the landscape to development and change
Fragile landscapes are more likely to be destroyed by a large number of tourists.
This implies that there must be a limit to the number of tourists who can visit such destinations, so as not to exceed the capacity.
The level of tourism development and infrastructure.
If development is rapidly taking place in an area without any effort to sustainably maintain the vegetation, it could lead to deforestation.
In this case, the carrying capacity has been exceeded.
The level of organization of the destination’s management.
The existing level of exposure of cultures and communities to outside influences and lifestyles.
If the local people in the tourist destination are exposed to other cultures (dressing, music etc) they are more likely to accommodate the tourists without complaining.
However, if they are less exposed to other cultures, then they are more likely to complain about it and their social carrying capacity will be excluded.
Level of economic divergence and dependency upon tourism.
If the tourist destination depends heavily on tourism, then the carrying capacity is likely to be exceeded.
However, if the destination has other sources of income, the local people are more likely to place strict rules on the number of tourists who can visit the destination.
The level of employment and poverty.
If local people in the tourist destination are gainfully employed they are more likely to impose strict laws on tourist numbers.
On the other hand, if the people are unemployed they are more likely to exceed the carrying capacity to cash in on large tourist numbers.
The number of tourists.
Type of tourists and their behaviour.
Sustainable tourism
Economic sustainability:
The livelihood of the local people is maintained.
With the development of tourism, the locals will benefit either through trade or by direct involvement in the industry.
Tourist revenue is sufficient to cater for the cost of repairing the facilities to maintain their quality
Tourism is managed such that tourists are encouraged to visit during off-peak periods to avoid excessive damage to the natural resources
Resources used for the construction of buildings and infrastructure are obtained locally. They are used with care to avoid waste
It involves undertaking effective research and development to obtain relevant data on tourist numbers and total revenues as well as new ways to improve the tourist facility
Environmental sustainability:
It minimizes environmental damage to the ecosystem to maintain the flora and fauna of the tourist destination.
For example, hunting and loud noise threaten the stability of the ecosystem and, therefore, are not permitted.
Tourism converses with the natural environment through the creation of nature parks and game reserves.
Waste is minimized and disposed of sustainably and traffic is managed in ways that minimize environmental pollution
Social Sustainability:
Tourist information bulletins and guidelines are published to stress the importance of sustainable practices in the tourist destination
The staff are trained on issues of sustainable tourism management to enable them to embrace the concept of sustainable tourism
The local community forms an integral part of tourism development and must benefit from tourist activities in the area
Tourism supports local communities by providing opportunities for the local economy to benefit socially and economically.
Butler’s tourism model:
Exploration: A new destination, with very few visitors.
They are usually adventurous travellers who have minimal impact.
Involvement: If the tourists like the new destination and the destination are happy to receive tourists, then there may be an investment in tourist infrastructure and involvement by locals.
Tourist numbers grow slowly.
Development: Tourism becomes a big business with further investment and involvement by TNCs.
Holidays become more organised with package holidays arriving.
Consolidation: The area becomes reliant on tourism.
Advertising and marketing attempt to maintain and increase tourism levels.
Facilities like beaches, swimming pools and golf courses may become the domain of tourists causing some local resentment.
Stagnation: There is some local opposition to tourists, there is no new investment, tourists become tired of the same destination and growth stops.
Rejuvenation: Tourism is relaunched through advertising, tourist arrival from new markets increases, new transport links are opened or tourism becomes more sustainable with local involvement.
OR
Decline: There is no relaunch, locals remove their support, TNCs leave and tourism begins to decline.
Urban Environments
1. Introduction to Urbanization
Urbanization is the process of population concentration into cities.
This phenomenon has been a defining characteristic of human development over the last century.
Understanding the factors that drive urbanization is crucial for comprehending the challenges and opportunities posed by the urban environment.
Key Concepts:
Urbanization:
The increasing concentration of populations in urban areas.
Rural-Urban Migration:
The movement of people from rural areas to urban centres.
Push and Pull Factors:
Forces that encourage people to leave rural areas (push) and attract them to urban areas (pull).
Causes of Urbanization:
Industrialization:
The shift from agrarian economies to industrialized societies often leads to the growth of urban centres.
Employment Opportunities:
Cities offer diverse job opportunities, drawing people seeking employment.
Technological Advancements:
Improved transportation and communication contribute to increased urbanisation
Urbanization:
Site: actual land on which a settlement is built; situation: r/s w/ its surroundings
Desirability enhanced with physical, social and economic factors (esp w/ industrialization and trade)
Industrial, service (recreation or transport)/residential role (incl open space) can change in proportion over time
Agricultural roles → steadily diminished in urban areas
Mostly in rural areas where population density is low
Industrialized areas with good access to resources
develop to become cities
Vertical Zoning: same building is used for 1 function:1 floor and another function on another floor to make up for the lack of space in urban areas
Range: max distance people are prepared to travel for G&S
Threshold: minimum number of people required for a G&S to stay in business
Sphere of Influence: area served by a settlement
Low-Order Goods: necessities (need only a small hamlet - dispersed, individual households w/small population to support) → limited range
High-Order Goods: luxuries (shared by a few villages due to specialization) → larger population
Conurbation: ≥ 2 cities merge, millionaire city & megacity,
Metacity: large-scale city regions
Megalopolis: cities sprawl and merge into 1
Large urban areas provide large number of high-order and low-order goods to a large population
Megacities:
Dominated by young adults (migrate searching for jobs) → high birth rates
Rapid EG and urbanization → large generation of wealth and large scale of environmental impacts new forms of planning and management to cope
Urban Growth and Economic Development:
Correlation between urban growth and ED
Commercial, industrial, political, administral and social function
Stimulus for development, EOS for health and education, ethnic, tribal and religious intermixing → weaken ties to traditional rural beliefs and customs
Cannot cope w/ growing population
high rates of unemployment
overloaded & overcrowded
transport systems
air, water and noise pollution
insufficient housing, sanitation and water supplies
deteriorating infrastructure and shortfalls in service delivery
Growing inequalities in access to infrastructure and services due to income gap → increased prevalence of social problems
Many health issues occur as an indirect impact ⇒ decline in quality of life
Urban Settlement Functions:
Trade and comms, mining and industrial areas, tourist resorts, govt services and high-tech industries (administrative center)
Settlements in favored areas have greater growth potential and a greater range of services and functions (may change over time)
Lowland coastal plains w/ links inland
Vance: development of settlements occurred as a result of trade interactions (external influences → centers of innovation for external commercial forces
Losch: cities grow due to transport accessibility that plays a large role in efficiency and can produce corridors or urban areas
Build new towns and new capital cities to deflect growth to accommodate the overspill population and ease chronic overcrowding + redistribute the state's wealth
Relocation of people to ensure their environment for living and working is ideal
Factors of Urban Economic Activity Patterns:
Bid-Rent Theory: limited land at the city centre that is most expensive as it's the most accessible land to public transport
Secondary peaks at intersections of main roads and ring roads (multi nuclei) & increased use of private transport in inner city areas
Low-Order Goods: neighborhood stores and shopping parades (shop clusters)
High-Order Goods: high street shops, dept stores
Out-of-Town Superstores and Retail Parks: large outlets close to residential areas
Congestion and inflated land price in city center → sub & counter-urbanization (increased accessibility to these sites) of more affluent households
Changes:
Economic change → more women in paid work → increased standard of living & car ownership
Demographic change → smaller households, more elderly → online shopping
Tech change→ more families own deep freezers (don't need to shop daily)
closure of high street shops due to changes in shopping habits (govt policies to revitalize retailing in central areas & inner-city redevelopment) - e.g. traffic-free zones
Leads to decentralization of other commercial activity and business parks in suburban sites
Central Business Districts: commercial and economic core of a city (coincides with/ place of peak land value)
Industrial Zones: inner-city areas and brownfield suburban sites (near airports) away from residential areas (pollution)
Those needing skilled labor, access to CBD and urban market for distribution
Cities are major centers of innovation, ideas and fashion → manufacturing centers + access to international market through a variety of labor (skilled and unskilled) → large markets
Planning urban economic activities: restrict development in particular areas (pollution)
Factors Affecting Location of Urban Areas:
Rich | Poor |
places with/ pleasant views and offer recreational activities → high ground that's safe and building standards account for risks | forced to live in areas of steep relief and be at risk of mass movements (informal housing) not protected against hazards |
increased use of private transport → edge of town areas are more accessible | located near city centre as it's close to jobs and they cannot commute from outer areas (live in overcrowded rooms as rent is expensive) |
may resist development of socially affordable housing / move to outer suburbs if this happens | |
can choose where they live and are more willing to pay for the housing → occupy higher-quality land ⇒ private developments prefer this |
Ethnic groups choose to live together for bonding and people to rely on (+ve segregation)
-ve segregation: certain groups excluded from certain areas (legally) - apartheid
Multiracial policy of locating all racial groups target on housing estate for racial harmony
Planning to achieve a balanced social mix (housing types and people)
People in rich neighborhoods may resist development of socially affordable housing / move to outer suburbs if this happens
Priv developments favor the rich: can choose where they live and are more willing to pay for the housing → occupy higher-quality land
Urban Poverty, Deprivation and Informal Activity in Urban Areas:
Deprivation can be measured through physical, social, economic and political indices
Slum: group of individuals living under the same roof in an urban area lacking ≥ 1: durable housing (protection from extreme climatic conditions), sufficient living space (max 3 in a room), access to improved water (sufficient, affordable, obtained w/o extreme effort), access to sanitation facilities, secure tenure (protection against forced eviction)
Dual Economy: mix of formal (foreign owned, more elite) and informal economic activity (small scale, labor intensive, locally owned)
Bazaar Economy: small trade and service establishments (family enterprises) - intense competition keeps prices low and supports a low standard of living
Street Economy: low earnings and standard of living (street hawkers, beggars, prostitutes)
Informal economy relieves the economic problems of the poor by using their energy and small-scale assistance to improve circumstances
Informal economy allows exploitation of the poor by the rich (cheap labor to keep cost of production down)
2. Urban Patterns and Land Use
Understanding the spatial organization of cities is essential for analyzing the urban environment. Urban patterns and land use are influenced by historical, social, and economic factors.
Key Concepts:
Land Use Zones: Areas within a city with specific functions, such as residential, commercial, industrial, and recreational zones.
Central Business District (CBD): The core of a city, usually characterized by high-density commercial and office buildings.
Residential Areas: Spaces dedicated to housing and accommodation.
Industrial Zones: Areas designated for manufacturing and industrial activities.
Urban Patterns:
Concentric Zone Model: Developed by sociologist Ernest Burgess, this model envisions a city with concentric rings, each representing different land use zones.
Sector Model: Proposed by Homer Hoyt, this model suggests that cities develop in pie-shaped sectors based on transportation routes.
Multiple Nuclei Model: Developed by Chauncy Harris and Edward Ullman, this model argues that cities have multiple centres of development.
Challenges of Urban Land Use:
Urban Sprawl: The uncontrolled expansion of urban areas into surrounding rural landscapes.
Gentrification: The transformation of a neighborhood through the influx of more affluent residents and businesses.
Urbanization, Natural Increase and Population Movements
Increase in the proportion of people living in urban areas caused by rural-to-urban migration, higher rates of natural increase in urban areas, reclassification of rural areas as urban ones
Cycle of urbanization, suburbanization, counter-urbanization and re-urbanization
Natural increase & birth rates
Rural-Urban Migration: movement of people away from countryside to towns and cities (people believe they're better off in urban areas)
Push and pull factors
Gentrification: reinvestment of capital into inner-city areas (residential and commercial areas)
Social displacement of poor people: house prices rise poor cannot afford and move out → young mobile population takes their place
Re-Urbanization: revitalization of urban areas and a movement of people back into these areas
Suburbanization: outward expansion of towns and cities (town extensions and increased scope of public transport)
Low IR → lower cost of living + willingness of local authorities to provide utilities - improved public transport → expansion of building societies
Counter-Urbanization: movement of population away from larger urban areas to smaller and newer towns on the edge of city limits
Due to high land price and crime rate, congestion, pollution, lack of community and declining services in urban areas
Urban Sprawl: uncontrolled growth of urban areas at their edges (prevented by green belts)
Urban system growth → increased need to provide access to clean water, sanitation and waste disposal → increase risk of diseases and burden on authorities
Expand transport facilities and telecom networks to attract new economic activity and match pop growth w/ infrastructure growth
The Causes and Consequences of Urban Deindustrialization
Long-term decline in employment in the manufacturing sectors of an economy → job loss
+ve: industries reduce workforce to increase productivity thru rationalization and mechanization → more competitive
Overseas competition from newly industrialized countries (NIC)/introduction of rival product → fall in DD → rationalization (cost cutting and decrease labor → unemployment)
Exhaustion of resources → increasing costs of raw materials/lack of capital - automation and new tech take over
Removal of subsidy/imposition of tax → higher COP (lay off workers to maintain profit)
Gains in service sector but cannot compensate for manufacturing loss
New jobs (part-time and low paid) mostly taken by women - older firms → less competitive and less innovative (unskilled labor)
Areas of disinvestment (massive outflows of capital and labor - filled by commuters from outside the city areas)
Reindustrialization: growth of high-tech industries, small firms and services
3. Urban Challenges and Solutions
The rapid growth of cities presents numerous challenges that require innovative solutions. Understanding these challenges is crucial for sustainable urban development.
Key Concepts:
Sustainability: Meeting the needs of the present without compromising the ability of future generations to meet their own needs.
Infrastructure: The fundamental facilities and systems serving a city, including transportation, water supply, and energy networks.
Challenges:
Traffic Congestion: The result of increased urbanization, inadequate transportation systems, and a growing number of vehicles.
Housing Shortages: High demand for housing can lead to shortages and increased prices.
Environmental Degradation: Urbanization often results in pollution, deforestation, and habitat loss.
Social Inequality: Disparities in income and access to resources can lead to social unrest.
Solutions:
Smart Cities: Integration of technology to improve the efficiency of urban services.
Mixed-Use Development: Combining residential, commercial, and recreational spaces to reduce the need for extensive transportation.
Green Infrastructure: Incorporating natural elements into urban planning to promote environmental sustainability.
Urban Microclimates
Structure of air above urban area and structure of the urban surface
Radiation and sunshine: industrial haze → reduced visibility ; greater scattering of soil water retention by dust & higher absorption of longer waves due to surfaces & CO2 → more diffuse sky radiation
Also heat produced by human activity
Summer: higher incidence of thicker cloud cover vs winter - increased convection and air
Pollution: higher incidence of radiation fog and smog
Concentration of hygroscopic particles increased condensation + higher day temps
Urban pollution and photochemical smog trap outgg radiant energy
Temperature: more heat energy retention and release → heat islands ; heating from below → increased air mass instability overhead ; big local contrasts btw sunny and shaded surfaces
Pressure and winds: severe gusting and turbulence around tall buildings → strong local pressure gradients from windward to leeward walls; canyon effect: deep, narrow streets are much calmer
Turbulence of air may be reduced overall
Higher building height and urban surface roughness → lower wind speed
Lack of avail moisture and higher temp: decrease in RH
Greater instability and stronger convection above built-up areas → higher incidence of thunder and more intense storms & less snowfall and briefer covers
Burning fossil fuels (domestic & commercial use): exceed energy inputs from sun
Buildings have a lower albedo: higher capacity to retain and conduct heat
Surface character, rapid drainage and lower wind speed: reduction in heat required for evapo(transpi)ration
Also changes airflow patterns → reduction of heat diffusion
Fewer open H2O bodies → less evaporation and plants → less transpiration
Urban area is warmer than surrounding rural area especially by dawn during anticyclonic conditions (calm, high pressure)
Develop pollution dome w/ cooler air above it that prevents pollutants from dispersing (day: prevent incoming radiation, night: prevent LWR from escaping → small temp diff)
Air Pollution Patterns
Pop growth in urban areas → industrial development energy and heating → increased air pollution → increase in no. of vehicles and DD for
Indoor air pollution: burning of firewood and paraffin (DCs) for cooking and heating as they do not have as much resources to cope w/ pop growth and provide services
LICs and NICs: weaker economies → minimal I in pollution control + use cheap, inefficient energy resources and cannot tackle air pollution effectively
Worsened by expanding car industries for ED (increased private car ownership)
Roads are also in a poor state which reduces the quality of vehicles
Pollution Management Strategies
Use more energy-efficient tech, public transport, car pooling schemes, cycling/walking → burn less fossil fuels
Use catalytic converters (reduce emissions of NOx)
Raise enforcement of emission standards (cheaper to lower emissions than clean up pollution)
Green spaces can reduce the effects of urban heat island (increased evapotranspiration → lower temperature → lower energy use), noise levels and air pollution
Tree shade has great cooling potential and improves air quality
Traffic Congestion Patterns, Trends and Impacts
More congested on weekdays, start of sch year, festivals and national holidays
Weekdays: morning and evening peak
Noise disturbance may cause people to move due to its associated health risks
Contested Land
2016 Rio de Janeiro Olympics: property boom in central favelas (drug gangs eliminated) displaced people for games-related purposes
Occupy movement: anti-capitalist protests to bring attention to the huge profits and inequalities generated by the financial services
Dharavi, Mumbai: connected by all railways and is a potential intl business destination → could be developed into a financial/service district but would displace 1m ppl
Slum: means of escaping poverty, home to thousands of micro-industries → attracts labor due to large informal economy
Depletion of Urban Green Spaces
Green spaces have little economic value and are not favored by developers yet is impt for physical and mental well-being
Increased thru compensatory afforestation projs but does not serve to decrease air or noise pollution (QOL factors)
Urban Crime
Crime hotspots: residential areas w/ lack of health centres, schs, recreational areas and police stations → easy access and lack of security
Areas w/ high no.s of offenders and crime targets commit crimes → increase incentive and ability to
Increase surveillance (more police officers on patrol and more CCTV use):
Improved street lighting and buildings designed to reduce dark areas
More taxi services during closing time of clubs and women-only taxis
Adopt a 0-tolerance policy towards crime
4. Future Trends in Urbanization
The future of urbanization is shaped by ongoing trends and emerging challenges. Analyzing these trends allows for proactive planning and sustainable development.
Key Concepts:
Megacities: Extremely large cities with populations exceeding 10 million people.
Rural-Urban Continuum: The idea that rural and urban areas exist on a continuum rather than as distinct entities.
Challenges to Address:
Overpopulation: Managing the strain on resources and infrastructure caused by rapid population growth.
Digital Divide: Ensuring equitable access to technology and information in urban areas.
Resilience Planning: Developing strategies to withstand and recover from natural disasters and other shocks.
Future Trends:
Smart Urbanization: Continued integration of technology to enhance urban services and improve quality of life.
Climate Change Adaptation: Cities must adapt to changing climatic conditions, including rising sea levels and extreme weather events.
Rural Revitalization: Efforts to balance urbanization by promoting development in rural areas.
Understanding the multifaceted nature of urban environments is essential for informed decision-making and sustainable development in an increasingly urbanized world.
Resilient City Design:
Cities are productive, innovative and trading centres that benefit from EOS and experience rapid pop growth
Also manifest major inequalities and deal with air and H2O pollution, congestion and inflated land prices)
Properly functioning transport network and energy, H2O and waste infrastructure for social mobility (reduce ecological footprint and vulnerability to pollution)
Dense population: less CO2/capita and higher potential for public transport → savings in heating and cooling as emissions/person decrease
Minimize travel dist→ use less space and infrastructure → reduce urban sprawl
Reliable SS of clean H2O and housing at an affordable and acceptable level
Clean up derelict sites to create more open spaces
Generating energy from waste (sell electricity back to urban grid): don't waste landfills
Prepare for intensified and more frequent weather events to reduce impact and recovery cost
Safer buildings and zoning (prevent building in unsafe areas), maintenance of sea walls and make the change to adopt cleaner energy
Eco-City Design
Eco-city: minimal environmental impact
Conserving non-renewables (reduce fossil fuels) and using more renewables → maintain acceptable waste production levels
Provide sufficient green spaces by reusing and reclaiming land
Encourage active involvement of the local community
Beddington 0 Energy Development (BedZED): environmentally friendly housing development in London - lower car mileage, space-heating requirements, hot H2O consumption, mains H2O consumption and electric power
C40: address climate change by working tgt to share technical expertise and best practice
Improve public transport, make infrastructure and H2O SS more reliable and efficient and more efficient outdoor lighting (lower energy consumption), make homes and offices more energy-efficient (save $ and the environment)
Consider social equity so that low-income communities can benefit as well
Bolivia's cable cars (El Alto - La Paz): affordable public transport route over a winding, congested highway
Helsinki and Hamburg: people powered mobility → provide cheap, flexible and well coordinated transport system that's competitive w/ private car ownership + increase pedestrian and cycle paths to eliminate the need for cars
Smartphone app: journey planner and payment mtd (limit users)
Smart Cities
City that is performing well in the economy, environment, people, governance, mobility and living conditions → I in social, human and physical capital (incl ICT) → sustainable development and high QOL
Good way to manage resources avail to the city (rising pop and dwindling resources)
Increased reliance on availability and quality of infocom tech and social infrastructure (intelligence and skills for urban competitiveness) → high proportion of educated workers
Need not be entirely new: can be readapted and upgraded from existing cities
Global Interactions
Changing Global Interactions and Power
Definitions:
Globalization: “the growing interdependence of countries worldwide through the increasing volume and variety of cross-border transactions in goods and services and of international capital flows, and more rapid and widespread diffusion of technology”(International Monetary Fund).
Globalization: It is a term that was invented to emphasize that the globalization of a product is more likely to succeed when the product or service is adapted specifically to each locality or culture it is marketed.
E.g., the presence of McDonald’s restaurants everywhere on the globe = globalization and the changing menus of the restaurants to appeal to the local tastes = globalization
Transnational Corporations (TNCs): Companies with branches in many parts of the world eg. Coca-Cola, Apple, MacDonald’s etc
The drivers of globalization:
Transportation improvements:
For example, faster and bigger aeroplanes enable labour and goods to move easily from one place to another; road transport network improvements have allowed for cheaper means of moving goods and people; sea transport – larger container ships – facilitates the transportation of large volumes of goods.
Freedom of trade:
For example, the EU, NAFTA, ECOWAS AND COMESUR have all contributed to allowing the free movement of goods, services, ideas and labour between member countries and across regional boundaries.
Improvements in communications:
E.g., improvements in telecommunication and the Internet have contributed to the exchange of ideas and services through the Internet.
Cheap Labour in developing countries – This is also aided by technology, for example, through outsourcing.
This makes it possible to outsource services to labour in different parts of the world.
Eg. Marking IB scripts online by different examiners in different parts of the world.
The drivers of globalization:
The KOF Index
The KOF Index of Globalization was introduced in 2002 (Dreher, 2006). KOF is a Swiss Institute of Business Cycle Research.
The overall index covers the economic, social and political dimensions of globalization.
Economic globalization is characterized by long-distance flows of goods, capital and services as well as information and perceptions that accompany market exchanges;
Political globalization is characterized by a diffusion of government policies.
Social globalization is expressed as the spread of ideas, information, images and people.
A.T Kearney Index
AT Kearney is a management consultancy firm that advises large corporations on international competitiveness.
Founded in 1926 in the US (Chicago), it publishes its index in the Foreign Policy Magazine.
The AT Kearney Foreign Policy index assesses the extent to which the world’s most populous nations are becoming more or less globalised, using twelve variables, which are subdivided into four “baskets” of global integration
Human and Physical Influences of Global Interactions
Political factors that affect global interactions:
Multi-governmental Organizations
MGOs are organizations or countries that come together to form a single entity mostly for trading purposes. Eg.
EU- European Union
USMCA- United States Mexico Canada Agreement
SADEC- South African Dev`t committee
UEMOA-West African Economic Monetary of Africa
ASEAN
MGOs allow state boundaries to be crossed feely to facilitate the free movement of goods, services, finance, and ideas.
Members are encouraged to abolish tariffs and promote the exchange of ideas in areas of security, trade, etc
Ways by which MGOS can promote global interactions
They promote the free movement of people between countries.
For instance, in the EU and ECOWAS people can move freely thereby we can say they are practising globalization.
Free trade allows the free movement of goods between member countries.
It promotes global interactions because it leads to the development of homogeneous landscape-saving brands, banks, etc.
Some of the MGOs use a common currency, which allows the free flow of goods and services.
This common currency unites those countries, such as the Euro-using countries, financially.
MGOs sometimes have common policies that facilitate global interactions.
For instance, CAP (Common Agricultural Policies) in the EU helps farmers in all EU countries to increase agricultural output by receiving support in the form of subsidies from the EU and guaranteed markets.
Membership in MGOs facilitates global interactions through the free movement of capital between member countries.
This means banks can transfer money at no cost from one country to the other.
Free movement of ideas between members as a result of the Internet.
For instance, if you are a member of the EU, you cannot be charged for roaming charges if you visit another EU country.
This does not always lead to global interaction because:
Joining groups like the EU means you would be unable to be independent as their currency is even controlled by the EU’s central bank.
Foreigners would dominate the countries.
How can export-processing zones facilitate global interactions?
Export processing zones allow countries to have access to goods that they cannot produce on their own at relatively low prices.
Free zones also help in global interactions because they help in the transfer of skills from advanced countries to developing countries through the training of workers.
Free zones help to stabilize a country’s currency against other countries’ currencies.
This improves global interactions because the country would be able to trade with another country, like the US, and get a lot of the foreign currency into their country.
Export processing zones lead to bilateral and multilateral relations between countries, which enable manufacturing companies to sell their goods to different parts of the world.
Development Opportunities
The multidimensional process of human development and ways to measure it:
UN Sustainable Development Goals criteria
Goal 1 – No poverty
Goal 2 – Zero hunger
Goal 3 – health and well-being
Goal 4 – Quality education
Goal 5 – Gender inequality
Goal 6 – Clean water and sanitation
Goal 7 – Affordable and clean energy
Goal 8 – Decent work and economic growth
Goal 9- Industry, Innovation and Infrastructure
Goal 10 – Reduce inequalities
Goal 11 – Sustainable cities and communities
Goal 12 – Responsible production and consumption
Goal 13 – Climate action
Goal 14 – Life below water
Goal 15 – Life on land
Goal 16 – Peace, Justice and Strong Institutions
Goal 17 – Partnership for the Goals
Human Development Index (HDI)
Developed in 1990 by the United Nations
The health dimension is assessed by life expectancy at birth
the education dimension is measured by the mean of years of schooling for adults aged 25 years and more and expected years of schooling for children of school-entering age
The standard of living dimension is measured by gross national income per capita
Scale of 0-1
gender inequality index (GII)
reproductive health, measured by maternal mortality ratio and adolescent birth rates;
empowerment, measured by the proportion of parliamentary seats occupied by females and the proportion of adult females and males aged 25 years and older with at least some secondary education; and
economic status expressed as labour market participation and measured by the labour force participation rate of female and male populations aged 15 years and older.
Changing Identities and Cultures
Cultural Diffusion
the spread of cultural traits from one place to another through the processes of cultural change.
There are several types:
Expansion diffusion – occurs when an idea develops in a source area and spreads into other areas while remaining strong at the source. E.g. spread of Islam from Saudi Arabia
Relocation diffusion – people who have adopted new ideas carry with them to a new location. E.g. Christianity to Africa from Europe.
Distance decay effect – The longer an idea takes and the further the distance it has to travel, the less likely it is to be adopted in new areas.
Adoption of mass culture – new cultural traits are taken in their entirety, perhaps abandoning old traditions
Adaptation/ Adaption of mass culture –cultural traits are modified so it can be accommodated within the context of an existing culture.
Cultural Hybridity– the extent to which different cultures are intermixed. Mixing of cultures can occur through; migration, media, transport revolution, Growth of global brands and even the internet
Cultural traits – characteristics of culture that give a culture its sense of identity – i.e what makes them different from others
Ethnicity – the shared sense of belonging to one ethnic group or another, based on ancestral lineage or cultural history.
Cultural diversity – the differences in cultural characteristics that are manifested in a given culture. Cultures that are not diverse tend to be homogeneous
Characteristics of a global culture:
Language
Dressing
Music
Movies/Television
Sport
Others(tourism, religion, education, architectural designs, etc.)
Barriers to global interactions:
Censorship of the Internet
The restrictions on migration to countries
Physical/environmental barriers
The resurgence of nationalism and anti-globalization movements
The double-edged effect of MGOs
Geopolitical and Economic Risks:
Threats to individuals and businesses include:
Hacking
Identity theft
The implications of surveillance for personal freedoms
Political, economic and physical risks to global supply chain flows
Environmental Risks:
Transboundary pollution (TBP) affecting a large area
Localized pollution resulting from the global flow of goods
Carbon footprints for global flows of food, goods and people
Polluting manufacturing industries
Food production systems for global agribusiness
Local and Global Resilience
Strategies to build resilience:
reject globalization
find ways of controlling the risks of globalization
adapt to the risks by implementing mechanisms to manage them in the event of their occurrence
The Geography of Food and Health
1. Measuring food and health:
Ways of measuring disparities in food and health between places:
Global Food Security Index (GFSI)
Takes into account four core issues of affordability, availability and quality of food across 113 countries
uses 28 indicators as a benchmark and goes beyond hunger in measuring food security
measures a country’s exposure to the impacts of a changing climate, susceptibility to natural resource risks and how countries are adapting to these risks
The Global Hunger Index(GHI)
Based on four indicators:
Undernourishment: the share of the population that is under-nourished
Child wasting: the share of children under the age of five who are wasted
Child stunting: the share of children under the age of five who are stunted
Child mortality: the mortality rate of children under the age of five
Calories per person/capita
measures the amount of energy contained in a given amount of food
measured in kilocalories per person per day (kcal/person/day)
High-calorie intake is associated with developed countries, and vice versa
Indicators of malnutrition
Stunted growth
Wasting
Undernourishment
2. Food systems and spread of diseases:
Sustainable Agriculture
The ability of a farm to produce indefinitely without causing harm to the ecosystem/environment
ensures that resources are used in such a way that future generations can still benefit from them
conserves natural resources
prevents environmental degradation
increases the profitability of the farm
The Environmental Costs of Increasing Food Production
The practice of monoculture by large TNCs causes significant damage to the natural environment.
The use of aggro-chemicals is harmful to the environment.
The cost of cleaning up chemical pollution is expensive.
It also leads to air pollution and greenhouse gas pollution from the farm.
Example: Methane.
It leads to the removal of hedgerows leading to deforestation.
Energy Efficiency Ratio:
measures the amount of energy input compared with the amount of output produced by the farm
two types of inputs: direct inputs and indirect inputs
Examples of direct inputs are planting, cultivation, labor, machinery, vehicle fuel, farm tools etc.
Examples of indirect inputs are fertilizers, electricity, irrigation, transport, pesticides etc.
The output-input ratio is calculated by dividing the total output by the total input
An efficient farm should have an EER≥1
Energy Efficiency Ratio=total outputs/total inputs
Factors affecting energy subsidies or energy efficiency ratio in different environments
Climate: Farms located in warm climates will need less energy than those in cold climates because colder ones need artificial light for crop growth.
Type of soil:
Loamy soil requires less fertilizer.
Sandy soil requires more fertilizer.
Type of crop cultivated: beans do not use a lot of nutrients. They fix nitrogen into the soil. Crops that produce protein require a lot of energy.
Relief/topography: When the land is relatively flat, it needs less energy, because it retains water and minerals easier.
Irrigation
The type of farming system: labor intensive or capital intensive
Two main improvements in physical processes that have led to an increase in food production:
Increased amount of farmland through converting brownfield sites and waterlogged areas to farmlands and cultivating forested areas. This has led to an increase in the amount of farmlands in Africa, Asia and other parts of the developing world.
The second reason is an increase in productivity, due to increased land size. The increase in agricultural productivity is the result of:
high-yielding variety of crops such as IR-8 rice and wheat. These crops have been genetically modified to increase the amount of output per hectare.
Mechanization of agriculture has made it possible for a large amount of land to be cultivated for farming
Use of chemical fertilizers. Despite its environmental impact, the use of agrochemicals has led to an increase in the amount of crop yield per land.
Irrigation has not only resulted in an increase in the amount of land needed to cultivate food, but it has also enabled experiencing seasonal rainfall to undertake dry season farming.
Rising incomes, leading to an increase in the demand for food and meat in MICs
Improved transportation, leading to an improvement in the distribution of food to areas experiencing food shortages
Better education, resulting in better food choices in favor of high-quality food
Mass media also plays a crucial role in determining the amount of food consumed by people in developed countries and urban areas
Disease/agriculture innovation diffusion can be classified into a number of types:
Expansion diffusion
occurs when a disease or agricultural innovation spreads from one place to another
the disease/innovation often intensifies in the originating region
as the disease/innovation expands into new areas, it is likely to weaken
recognized in the recent H1N1 flu that had its source in Mexico
Relocation diffusion
a spatial/geographic spread process
the disease/innovation leaves the areas in which it originated as it moves into new areas
Example: The migration of people with HIV or Measles
Network diffusion
occurs when the disease/innovation spreads through transportation and social networks
example is the diffusion of HIV which spread along important transport routes in Southern African countries with developed road networks, as well as social (sexual) networks
Contagious diffusion
spread depends on direct contact
mostly applicable to disease diffusion
the process is strongly influenced by distance because nearby individuals or regions tend to have a much higher probability of contact or infection (incidence of the disease) than remote individuals or regions
Hierarchical diffusion
involves the spread of disease through an ordered sequence of classes or places,
Example: from large cities to remote villages
assumed to be downwards from larger cities to smaller centres.
3. Stakeholders in food and health:
The following organizations have made significant contributions towards achieving the SDGs related to food security and diseases:
Food and Agriculture Organization (FAO):
Help eliminate hunger, food insecurity and malnutrition
Make agriculture, forestry and fisheries more productive and sustainable
Reduce rural poverty
Enable inclusive and efficient agricultural and food systems
Increase the resilience of livelihoods to threats and crises
World Food Programme
providing emergency assistance, relief and rehabilitation, development aid, and special operations
committed to ‘end hunger, achieve food security and improved nutrition by 2030‘
contributes to achieving this goal by providing food and food-related assistance to people in conflict-affected countries where people are likely to be undernourished
World Health Organization (WHO)
providing leadership on matters critical to health and engaging in partnerships where joint action is needed
shaping the research agenda and stimulating the generation, translation and dissemination of valuable knowledge
setting norms and standards and promoting and monitoring their implementation
articulating ethical and evidence-based policy options
providing technical support, catalyzing change, and building sustainable institutional capacity
monitoring the health situation and assessing health trends
How can TNCs or Agribusiness influence food consumption habits?
The production of food on a large scale by TNCs makes food available to areas that do not have sufficient food supply because the TNCs can export food to such hunger-stricken countries.
TNCs may sell food at a cheaper price to local consumers since they can reduce costs due to the large-scale nature of their operations.
By so doing, they are capable of producing more at a lower cost.
Since most foods produced by TNCs have preservatives, it increases the lifespan of food on the shelves.
This means that the consumer will not suffer from food shortages resulting from poor storage facilities or the perishable nature of the food.
TNCs also give consumers the opportunity of making food choices according to their preferences.
The wide range of options available means the consumer buy food that meets their dietary needs and food preference – key ingredients in the definition of food security
Criticisms of TNC/Agribusiness
At the input stage, the natural environment and natural breeding selection are losing out to genetically modified seeds.
Large land grabs by TNCs deny the people power to cultivate food for domestic consumption, possibly leading to food shortages
Food is preserved, processed package-branded and marketed such that food is becoming increasingly unrecognizable.
Example: it is becoming increasingly difficult to link processed meat products to the actual type of animal.
They may encourage or emphasise the growing of non-food cash crops rather than food crops which would limit the consumer’s choice of food.
TNCs often sell processed food, which has less fibre, thereby increasing the consumer’s risk of contracting diseases of affluence.
The Media and advertising companies can also present food adverts which present unhealthy food as suitable for consumers.
This could compel them to switch from eating healthy food to unhealthy one.
They may gain control of the supply of seed for one or more basic crops; this seed may then be priced beyond the means of the average farmer or the seed may require higher than affordable investments in infrastructure or equipment for high yields to be obtained.
4. Future health and food security and sustainability:
Possible solutions to food insecurity
Economic solution
Investment in agriculture:
financial investment such as agriculture subsidies given by the government could be given to farmers to increase food production.
Loans:
these could be micro-loans given to rural farmers at low-interest rates to invest in farming.
Food crop cultivation:
this will make food available for consumption, rather than investing in feed industries producing biofuels.
Commercial agriculture:
this will encourage large-scale farming of food crops that could potentially make food available at cheap prices or for export to increase the farmer’s revenue
Political solution
Food aid:
helps to alleviate food shortages because they serve as an emergency source of food during war or natural disasters like famine or drought
Fairtrade:
adopt policies that meet the livelihood of the people, respect/preserve their local culture and protect/use environmental resources wisely
Free trade:
an agreement between two countries to trade between themselves without any restrictions or barriers
Technological Solution
Irrigation:
to invest in dry-season farming/irrigation to provide water for crop farming and livestock production
Mechanization of agriculture:
investment in road infrastructure by extending feeder roads to farming areas, and providing tractors and other forms of farm machinery to farmers to cultivate crops on a large scale
Food waste reduction:
efforts must be made to reduce the amount of food waste generated in hotels, restaurants and supermarkets
Contemporary approaches to food production:
Genetically modified organisms (GMOs)
plants or animals whose genetic makeup(DNA) has been transformed by scientific engineering
leads to the development of a new organism whose DNA is different from the natural one
Vertical farming
the growing of crops vertically, in layers, especially in urban areas
beginning to gain popularity in the developed world, where food production is taking place in tall buildings in urban centres
In vitro, meat
also known as cell-cultured meat, clean meat or synthetic meat
the production of meat using tissue engineering technology
a cell is taken from a living animal and placed into a protein-rich liquid, causing the cell to grow without the need for the animal body
the cells multiply to produce artificial meat
not all forms of meat can be produced this way
Prevention and treatment in managing disease:
Two main systems of healthcare delivery:
Preventive Health Care:
Measures taken to prevent a disease from occurring as opposed to the treatment of a disease.
In other words, preventive health care emphasizes the need to prevent the incidence of the disease before it occurs.
Example: Polio vaccination takes place in Ghana every year to prevent the spread of polio among children.
Curative Health Care:
Involves treating the symptoms of the disease after the person has been infected.
Curative health care involves massive investment in medical infrastructure by the government in the form of hospitals, nurses’ training colleges and medical schools to train doctors as well as providing enough resources to make them functional.
Most countries in the world focus on curative health care rather than preventive health care.
Fieldwork
What is Fieldwork?
Fieldwork is a cornerstone of geographic learning. It's more than just studying textbooks or maps; it's about actively engaging with the world. Fieldwork allows students to step outside the traditional classroom walls and use this real-world environment as a laboratory.
There are three key aspects to fieldwork:
Observation: Hone skills to identify and record geographical data. This data could include anything from landforms and vegetation to human settlements and infrastructure.
Recording: The information gathered needs to be documented. This might involve taking notes, sketching maps and diagrams, or even capturing photographs and videos.
Analysis and Interpretation: Once data is collected, it is analyzed and interpreted to understand the relationships between humans and the physical environment. This analysis could involve identifying patterns, trends, and cause-and-effect relationships.
By combining these elements, fieldwork allows one to learn about geography and experience it firsthand. Students can see how geographical theories studied in class play out in the real world.
Identifying a Fieldwork Topic
Choosing the right topic is crucial for a successful fieldwork project. Here's a breakdown of the key characteristics to consider:
Short and Precise: Keep it clear and concise. The topic should clearly state what is being studied and where. It should be easy to understand at a glance.
Researchable and Clear: Make sure there's enough information available to gather and analyze. A topic that's too broad or lacks sufficient data will be difficult to investigate effectively.
Geographically Relevant: Remember, geography is all about the relationship between humans and the physical environment. The topic should focus on this connection.
Unambiguous: Avoid topics that could be interpreted in multiple ways. A clear and well-defined topic will lead to a more focused and insightful study.
For example, instead of a broad topic like "Urbanization", a more focused and geographically relevant option could be "The impact of urban sprawl on green spaces in [City Name]."
Formal Requirements
There are specific formatting and presentation guidelines for the fieldwork report. These ensure clarity, consistency, and proper referencing of work. Here are some key points to remember:
The IA must not exceed 2500 words. Only footnotes of less than 15 words and text boxes with less than 10 words in them, the bibliography, and appendices are excluded from the word count.
The IA is a piece of fieldwork based on primary data.
The topic must relate to the syllabus and have a spatial element to it.
It must be on a local scale, but not necessarily close to the local area of the school.
Two or three hypotheses are recommended.
Good map work with annotations and photographs that help to give locational context is recommended.
It may be a good idea to use double spacing for your writing - check with a teacher.
If using questionnaires, avoid questions that give Yes/No answers as this will limit the way data can be presented. Avoid long qualitative answers which will impinge on the word count.
Creative presentation of data is rewarded, including hand-drawn graphs and charts.
The focus of the write-up is the analysis, purely descriptive work will not produce high grades.
Teacher support is vital. Seek advice from your teacher for completion of your work.
Academic honesty is of the utmost importance - use consistent, clear referencing.
Formulating Objectives
Objectives are like mini-goals for the fieldwork project. They provide a clear direction for the research and help stay focused. Here are some key characteristics for effective objectives:
Specific: Clearly state what the aim is to achieve with the fieldwork. Don't use vague terms like "understand" or "learn more about." Be specific about what aspects you want to understand or learn.
Measurable: How will you know if you've achieved your objectives? Formulate them in a way that allows you to measure your progress and evaluate the success of your fieldwork.
Focused and Narrow: Don't try to cover too much ground. Keep your objectives focused on a specific aspect of your chosen topic.
Realistic and Achievable: Be realistic about what you can achieve within the timeframe and resources available for your fieldwork.
Logical: Structure your objectives in a logical flow. Typically, they start with understanding the location and background, then move on to specific aspects, and finally consider future prospects.
Related to the Topic: Don't simply repeat your topic in your objectives. They should elaborate on what you'll be investigating within the broader topic.
For example, an objective for the topic "The impact of urban sprawl on green spaces in [Your City Name]" could be: "To analyze the change in green space coverage within a specific district of [Your City Name] over the past decade due to urban development."
Data Collection Methods
There are various tools and techniques that can be used to gather data during fieldwork. Choosing the right method depends on the specific topic.
Here's a closer look at some common data collection methods used in geography fieldwork:
Observation:
This is a fundamental skill in geography. It involves using your senses to actively record information about the environment. Here are some things to keep in mind:
Advantages: Useful in situations where interviewing isn't feasible, allows for studying natural processes as they unfold.
Limitations: Can be subjective (influenced by your own biases), and limited in scope for large areas or complex phenomena.
Interviewing:
Talking to people directly can provide valuable insights and perspectives.
Advantages: Offers first-hand information from people who live or work in the area you're studying.
Limitations: Interviewer bias can influence responses, and language barriers may be a challenge.
Recording:
This involves capturing information in a permanent form for later analysis.
Advantages: Creates a lasting record of your observations, and allows for organization and presentation of data.
Limitations: Weather conditions can damage notes or equipment, and lost materials can hinder analysis.
Measurement:
This method is useful when you need to quantify specific aspects of your environment.
Advantages: Provides precise and objective data for analysis, and allows for comparison with existing data sets.
Limitations: Requires proper use of tools (which may be limited in availability), accuracy can be affected by tool malfunction or user error.
Sampling:
Since it's often impractical to study an entire population, sampling allows you to collect data from a representative subset.
Advantages: Saves time and resources, and allows for detailed investigation of a smaller group.
Limitations: Incomplete data can lead to inaccurate conclusions if the sample isn't truly representative.
Sketch Map Drawing:
Creating a sketch map is a visual way to document the spatial relationships between different features in your study area.
Advantages: Helps visualize the layout and connections between geographical elements, and provides a clear reference point for your observations.
Limitations: Whilst it can increase your final grade, accurate sketching requires skill and time.
Presenting Your Findings
Once you've collected your data, it's time to showcase your findings! Here are two key aspects to consider:
Geographical Significance:
Explain how your fieldwork results contribute to the broader understanding of geography. This might involve:
Relating your findings to existing geographical knowledge about the area.
Highlighting the relationships between physical and human aspects of the environment.
Problems Encountered:
Be honest about any challenges you faced during data collection. Explain how these problems may have affected your results and what you might do differently next time.
Follow-up Activities
Fieldwork doesn't end with data collection. Here are some essential follow-up steps:
Data Analysis: This is where you make sense of your data. Organize, sort, and interpret the information you gathered. Look for patterns, trends, and connections between different data points.
Refine Fieldwork Materials: Finalize any sketches, maps, or tables you created during data collection. Ensure they are clear, well-labeled, and ready for inclusion in your report.
Compare Information: If you worked in a group, compare your findings and combine data for a more comprehensive picture. Discuss any discrepancies and work towards a cohesive analysis.
Report Writing: Compile your findings into a final report that follows the required format. This typically includes an introduction, methodology, results, discussion, and conclusion sections.
Ethical Considerations:
Respect for the Environment: Minimize your impact on the study area. Avoid damaging vegetation, disturbing wildlife, or littering.
Respect for People: If interviewing people, obtain informed consent and ensure anonymity if promised. Be courteous and respectful of their time and privacy.
Safety:
Plan Ahead: Conduct a risk assessment of your study area and identify any potential hazards.
Work with a Partner: Never go on fieldwork alone, especially in unfamiliar areas.
Inform Others: Let someone know where you're going, what you'll be doing, and when you expect to return.
Be Prepared: Dress appropriately for the weather and terrain. Bring necessary supplies like water, sunscreen, insect repellent, and a first-aid kit.
Technology:
While traditional methods like pen and paper are still valuable, consider using technology to enhance your fieldwork:
GPS Devices: Track your location and record waypoints for creating accurate maps.
Digital Cameras: Capture high-quality photos and videos to document your observations.
Data Collection Apps: Use specialized apps to record observations, conduct surveys, or collect measurements.
