A Level Geography Population And Environments

What is Population?

the amount of people in a defined area

What are population parameters?

different ways in which the population is measured, and these are very useful to gain some insight into the characteristics of a population

what are the 4 population parameters

Distribution,Density,Numbers,Change

how does the climate affect population

affects agriculture as crops need certain conditions to grow, and food is needed to support a population.

also affects the incidence of disease, as some diseases thrive in certain climates, which affects the population.

how does soil affect population

water content, nutritional content, and overall quality of the soil affects agricultural productivity. important in providing food to support populations.

how does natural resources affect population

needed for a population to grow and be supported. clean water supply is needed for hygiene, sanitation, agriculture, and drinking

what is a development process?

the process of society advancing over time , hence 'developing'

what happened during the green revolution?

the process of using technology and more efficient farming supplies/practices in agriculture to maximise yields in the 50s and 60s

overall created more food, especially in developing countries, meaning a larger population could be sustained

how many people were able to be fed as a result of the green revolution?

an estimated 1 billion people

what happened during the Industrial Revolution?

transition from majorly labour-intensive industry to technology manufacturing processes, including the use of machinery, fossil fuels, and factories. revolutionised agriculture, the manufacture of goods, transportation. medicine and other aspects of society, overall making life less labour intensive for many people.

how did population change as a result of the IR?

At the start of the Industrial Revolution, the population grew by 57%, and 100 years on the population grew by 100%.

what were the global population pattern trends?

world's population stayed below 1 billion until 1804 , yet to reach 2 billion it only took just over 100 years. Global population growth has truly been rapidly increasing since the 1960s, where the population had doubled from the start of the 20th century. Population is estimated to reach 9 billion by 2050.

what percentage of people live in urbanised areas and what is it expected to rise to?

55% and this is expected to rise to two thirds of the population by 2050

characteristics of areas that are sparsely populated

often have uninhabitable conditions, meaning the population cannot be supported, for example there is a lack of food to accommodate the population.

characteristics of areas that are densely populated and example of place

can produce a large amount of food. some densely populated areas of Bangladesh have very fertile soil, and the floodplains are good for crops, meaning many people choose to live in these areas.

how have rates of population growth changed globally?

there has been a shift from rapid population growth in richer countries, to rapid population growth in poorer countries

how much has food production increased in the last 50 years?

tripled

how much has global arable land increased in the last 50 years?

67 million hectares

why has global food production increased?

● An increased use in farming machinery (e.g. combine harvesters) which allows for more crops to be collected in a quicker time frame.

● Increased use of other farming resources, such as herbicides and pesticides, to maximise yields.

● Better farming management to maximise yields and create more farmable land.

what has happenned to food production in Asia and Northern Africa?

wheat and rice production has increased due to higher yields

what has happenned to food production in Latin America and the Caribbean?

maize production has increased due to methods of land expansion (creating more arable land).

areas with high crop yields

● Eastern Asia ● North America ● Western Europe

areas with moderate crop yields

● India ● South America ● Western Africa

areas with low crop yields

Central Australia ● Saharan Africa ● Eastern Russia

which continent consumes the least calories

Africa consumes the least calories out of every continent: over 27% of Africa's population are affected by severe food insecurity

which 2 continents consumes the most calories

North America then Europe

which continent has seen the fastest growth in consumption rate

Asia's consumption rate has seen the quickest growth; China's consumption has increased by nearly 1000 calories in 50 years.

statistics of cereals in food consumption?

50% of calories globally are from cereals, more so in developing countries (54%)

In Africa and parts of Asia, cereals account for up to 70% of energy intake , whereas in high income countries this number is around 30%

Wheat consumption is highest in developing countries and increasing.

Coarse grains are a major contributor to Sub-Saharan Africa's cereal intake.

how has meat consumption been increasing?

There's been a threefold increase in meat consumption in Asia since the 60s, and China specifically consumes nine times the amount of meat they once did.

who consumes the most Fats, oils and sugars

Consumption of these products are highest in HICs due to the consumerist culture.

Consumption is rapidly increasing in developing countries , but is still slower in the least developed countries.

name 4 physical inputs of the agricultural system

climate factors - sun and rain

soil - mineral content, saturation

location (altitude, relief etc)

pollination

name 4 human inputs of the agricultural system

farming machinery

fertilisers and pesticides

seeds and livestock

labour

name 3 processes of arable farming ( plants ) of the agricultural system

planting seeds

tending to land

harvesting

name 3 processes of pastoral farming ( animals ) of the agricultural system

tending to livestock

breeding

collecting procedure

name 3 useful outputs of the agricultural system

food crops ( cereals, fruit and veg)

other crops (cotton and silk)

animal produce ( milk, meat )

name 3 losses and other outputs of the agricultural system

losses in natural disasters, such as droughts and floods

waste e.g. manure

unused, wasted food

what is agricultural productivity?

Agricultural productivity is the amount of useful outputs (yield) in proportion to the amount of inputs, showing the efficiency of the farm

characteristics of high productivity farms

high yields are being achieved through low inputs

saving time, labour, and money

also usually have little to no losses as they are efficient, e.g. they may reuse excess crops to feed livestock, saving money.

what is intensive farming?

high inputs and highest possible outputs. include lots of labour, or high capital inputs such as machinery - to maximise yields

what is extensive farming?

Low labour and capital inputs in relation to agricultural land, thus usually producing lower outputs

what is commercial farming

Agriculture with the intention of providing yields that can be sold commercially

usually associated with intensive farming, as more profits can be made using this management strategy.

what is subsistence farming?

Self-sufficient farming, where crops are grown only to support those growing the crops family or community, with little or no profit.

what are some climatic factors that drive agricultural productivity?

precipitation, temperature, humidity, and winds

how does soils affect agricultural productivity?

Issues with soils - such as erosion, flooding, or desertification - may also decrease productivity, as low nutrients in soil will affect plant growth and animal food supply. Soils effects on agriculture will be discussed in more detail.

how do extreme weather events decrease productivity and give examples

s likely to decrease productivity, as these events can devastate large areas of arable and pastoral land

(floods, droughts, tropical storms, wildfires)

how are yields estimated to be affected in asia due to temp changes

it is predicted that per 1°C temperature rise, rice yields will decrease by 20%

extreme weather events occurring in africa...

severe droughts in east africa

rainfall becoming scarce and unpredictable

In the past 10 years, 7 years have experienced severe droughts

what are some soil problems occurring

erosion, desertification, and salinisation are projected to increase in some areas due to higher temperatures

continue to make arable land unusable

the problems of pests, insects and plant diseases

projected to increase in some areas due to climate change, which will continue to decrease agricultural productivity in some areas

what is topsoil?

topsoil is the upper layer of soil, responsible for providing the majority of nutrients and structure for agricultural activities

what is the problem if top soil wears away

soil erosion

what is water erosion

water erosion is the degradation and wearing away of soil due to water

why does water erosion occur

climatic factors

lack of plants for interception

topography (e.g. on a slope, soil can wash away quickly due to rapid surface runoff)

agriculture

how does agriculture contribute to water erosion?

the removal of plants/ natural interceptors

poor contouring

poor irrigation

forms of water erosion: what is sheet erosion?

the washing away of soil in a uniform manner leading to the widespread removal of topsoil

forms of water erosion: rills and gullies?

rills are small streams that develop by erosional flowing water. they often develop on slopes, as water flows naturally due to gravity.

overtime rills can develop to large ravines known as gullies.

huge amounts of soil and nutrients washed away.

exacerbated by agriculture as fields of empty crops, plants or trees allow for streams to develop

forms of water erosion: what is riverbank erosion?

the degradation of river banks, causing large sections of the bank to be eroded away. bad for agricultural as it destroys land.

e.g. land surrounding Brahmaputra river in Asia have been eroded through this erosion

what are issues of water erosion for agricultural?

soil washed away, causing crops to become unstable and crops may be washed away

nutrients are leached to lower parts of the soil, or entirely washed away

weeds can spread from other areas if carried in water

rills and gullies can obstruct farming equipment, reducing the amount of agricultural land and causing potential dangers

where and why is wind erosion more prominent? (2 places)

in dry climates as the soil particles are less cohesive meaning the top soil becomes unstable

areas of agricultural land are more vulnerable to wind erosion as ploughing can loosen the soil particles

the difference on wind erosion depending on the size of soil particles (3)

creeping- slowly rolling along the floor

saltation- bouncing

suspension- carried in the air

why is wind erosion bad for agricultural?

topsoil is blown away- less nutrients for growth

crops can be buried in thin layers of soil after high winds, which can damage crops and restrict sunlight

lowers a soils capacity to store water as depth of soil is reduced, causing soils to become dryer

what is structural deterioration ?

the loss of structure of the soil, especially in the pores between soil particles that contain air

why does structural deterioration occur?

livestock can trample ground which compacts the soil and removes natural spaces

removing crops and plants

farming machinery causing soil compaction

what are the problems of structural deterioration for agriculture?

Water cannot infiltrate due to the lack of space in the soil, meaning plants may become dehydrated.

Root cells need air to survive, which they get from the soil environment. Structural deterioration can remove air pockets and essentially suffocate roots

Root growth may become obstructed as the roots cannot infiltrate compacted soil.

Soil is harder to work with when the structure has deteriorated, e.g. it is harder to plough or till.

what is waterlogging?

refers to when the soil becomes oversaturated with water. A soil may be considered waterlogged when it is so oversaturated that there is no longer oxygen present in the soil, meaning plants cannot respire aerobically (with oxygen).

what are the reasons waterlogging occurs?

waterlogging may happen naturally due to heavy rainfall and flooding

may also occur due to structural deterioration (as water cannot drain) or other farming practices, such as too much irrigation

negative effects of waterlogging on agricultural productivity?

limited oxygen supply in the soil, restricting plant respiration and causing them to 'drown'.

Roots may also rot in stagnant water, killing the plant or stunting growth

leach away minerals for plant growth, or bring unwanted minerals to the topsoil, such as salts

Water lowers the temperature of soils, which slows photosynthesis.

what is salinisation?

the increase of salt content in soil, usually causing a crust of salt on the topsoil

why does salinisation occur?

when saline water rises to the surface of the soil, and then water evaporates, this leaves salt concentrated in the topsoil

the effects of high temps on salinisation?

may draw saline soil water to upper parts of the soil

what happens when groundwater levels rise ( salinisation ) ?

salts from lower levels of the soils are brought upwards.

how does salinisation affect agriculture?

Salts are toxic to plants, which can reduce the fertility of plants, reduce yields

affects osmosis - dehydrates the plants

may also break up natural soil structure , affecting plant growth and productivity

what is desertification?

is where fertile land becomes dry, cracked and desert-like, leaving land unproductive

how is desertification caused

little precipitation and high temperatures dries out soils

Irrigation may also drain underground water stores or cause salinisation, eventually causing desertification.

which problems does controlling water levels help?

waterlogging, water erosion and salinisation as they can all be caused by a water surplus

which problems does drip irrigation solve?

helps to avoid overwatering ( using less water to efficiently water plants)

how can runoff be redirected?

contour ploughing - where lines are contoured across a downhill slope so that water does not flow downhill quickly in the contours, but is obstructed

terracing - where steps are carved into a hillside to spread out water levels, rather than it flowing downhill

diversion channels - runoff can flow into channels that provide the quickest route, redirecting them away from the crops

what are the positive effects of soil management from moving livestock?

ensures the ground is not trampled extensively, limiting structural deterioration

this also avoids overgrazing, so that plants can keep the structure of the soil intact

what are cover crops and the benefits of cover crops for soils?

it is a crop that is primarily planted for maintaining soil quality

the crop is used to cover a bare field

cover crops maintain the structure of the soil, as plants hold soil together with roots, take up soil water, and protect soil particles from wind and rain

waterlogging, water erosion, wind erosion and structural deterioration may also be prevented

what is multiple cropping and what are the benefits for soil of multiple cropping?

the process of planting more than one crop in an agricultural area during an agricultural season

having multiple crops on agricultural land stops certain nutrients from being overexploited, maintaining soil quality

multiple crops provide more fertile and healthy soi

what are the benefits of changing soil composition?

can limit wind erosion and structural deterioration, as adding certain materials can encourage a well binded soil with natural pores

adding mulch to soils can protect small soil particles from wind erosion as it binds the soil together

what are the benefits of windbreaks for soils?

bushes, trees or man made windbreaks such as netting can obstruct winds. can limit wind erosion on arable land, higher yields

what is food security?

the concept of having available, accessible, and affordable food that is safe and nutritious, so that people may live a healthy lifestyle

how many people experience chronic hunger globally?

1 in 10 people

how does increasing access ensure food security?

Increasing a country's access to foreign markets means they can import food, increasing food security.

Trading agreements such as trade blocs can be very beneficial to a country that is struggling to provide enough food for its population.

aid and relief can also increase food security

how does increasing amount ensure food security?

Strategies and new technology (e.g. GM crops)

Managing farms more successfully through training, farming equipment, and high yielding varieties

how does increasing efficiency ensure food security?

increasing the efficiency of a farm can save time and food, meaning overall there is more food available

may be more affordable as there are less expenditures.#

Equipment and better management can produce more crops in less time

Waste can be reduced by harvesting natural resources and having better storage.

how did the green revolution improve food security?

improved the efficiency of farms

increased use of fertilisers, pesticides, mechanisation, irrigation and development of high yielding varieties

thought to be responsible for increased calorie intake in LICs

problems with the green revolution?

salinisation caused by irrigation, or farmers unable to repay loans on expensive equipment

what is the GAFSP - global agriculture and food security programme

global partnership that supports sustainable agriculture in developing countries, with the intention of creating food security. works to increase the efficiency of small farmers

e.g. funded programme in Rwanda increased some yields by 30%

what is infant mortality and what are trends of it?

the amount of infants that die per 1000 births

highest in Africa as well as pakistan, afghanistan and Laos

usually lower in HICs

the incidence of non communicable diseases and communicable diseases

HICs - non communicable diseases

LICs - communicable diseases

what is the epidemiological transition?

a theory regarding population change, specifically how morbidity changes as a society develops over time

the model outlines how as time goes on and society develops, the number of deaths from infectious diseases decrease

what is stage one of the epidemiological transition model ?

pestilence and famine:

infectious disease

many pandemics

high mortality due to disease

what is stage two of the epidemiological transition model ?

receding pandemics:

advances in technology

advances in medicine

social change - hygiene etc

less infectious disease

what is stage three of the epidemiological transition model ?

Degenerative & man-made diseases:

Developments in society creating diseases, e.g. coronary heart disease . from lack of exercise

Infectious diseases are low

how does climatic factors influence the incidence of disease?

many diseases are dependent on the environment (e.g. temperature, precipitation, humidity etc)

what is an example of a disease that are influenced by climate?

vector born diseases:

diseases caused by a carrier passing on a pathogen to a human e.g. malaria where mosquitoes act as a vector to transmit the pathogen

usually relient on specific conditions that allow the vectors to live and breed. e.g. high temps and access to bodies of water

how do extreme weather events affect diseases?

Cholera, typhoid, dysentery, and diarrhoeal diseases all spread in water, meaning there are commonly outbreaks after natural disasters such as floods and tropical storms

how does topography and geographical location affect disease?

Low-lying areas, especially floodplains and valleys next to steep hills, are particularly prone to water-borne disease as low-lying areas can have poor drainage, and can stagnant water can develop