Geography - WATER CYCLE AND INSECURITY CASE STUDIES

Example of water insecurity - drought and why

Southern Madagascar - less rain and more sandstorms leading to desertification.

This has led to malnutrition and migration to the north and disease

Causes of the Murray Darling Basin water crisis

Urbanisation

Climate change uncertainty

Irrigation - MDB uses 60% of all irrigation water in Aus

Agriculture - covers 80% of basin

Unsustainable use

Land clearing - for agriculture and urban development

Political impacts of the MDB water crisis

New national plan for water security - taking too long for states to agree on water allocations as there are 5 states in the MDB

Environmental impacts of the MDB water crisis

Salinity

Low water flows - total flow at Murray mouth reduced by 61%. River stops flowing 40% of the time in each month

Wetlands disturbed - river modification inc. dams and water diversion for irrigation

Impact on lower lakes - coorong nat park internationally significant water bird and wetland site

Examples of international water conflict

GERD - Ethiopia,Sudan, Egypt

Lake Chad - Chad , Nigeria , Niger , Cameroon

Brahmaputra River - India, China

Tigris-Euphrates Basin - Turkey, Syria, Iraq

Examples of regional water conflict

Colorado river basin - USA , Mexico

South India - Karntaka and Tamil Nadu

Horn of Africa - Somalia

Gaza - Palestinian Territories

Examples of local water conflict

MDB - Australia

Bolivia - Cochabamba ‘Water War’

GERD - Who owns the Nile waters ?

1959 the Nile agreement signed giving 2/3 of Niles water to Egypt and 1/3 to Sudan
Agreement was signed by colonial powers- Ethiopia refused to recognise its legitimacy

GERD - Background

The dam is a multipurpose scheme HEP and water for irrigation of new agricultural lands.

Excess electricity generated can be sold to other countries.
$5 billion cost has been partially met by citizens buying bonds
The Ethiopian Government completed the dam in 2020 and began filling reservoir

GERD - Positive impacts

Will provide HEP improving peoples quality of life-clean renewable source of energy
-Risk of flooding downstream will decrease
-Will keep the Nile's flow stable throughout the year rather than it's previous fluctuations
-Reservoir can be stocked with fish to benefit Ethiopia

GERD - Political impacts

Risk of unilateralism (only benefitting Ethiopia) and regional instability

-Caused tension with Egypt as flow of the Nile has reduced during filling period
-Egypt and Sudan concerned how much water Ethiopia will release in times of drought

Ethiopia now has control over water flow in Nile

GERD - social impacts

-Local tribal groups have been displaced , inadequate compensation and resettlement support
-60% of Egypt's water comes from the blue nile(water security)
-Increase in malaria-breeding ground for mosquitos
-During times of drought there is no current agreement on how this will be managed
-Downstream there will be reduced flow of nutrients affecting crop production
-Reduction in fish stocks as breeding fish cannot make their way up to headwaters

-improved water availability due to controlled flow may allow for expanded irrigation schemes supporting food security in Ethiopia

-reduction in flooding during rainy seasons

GERD - economic impacts

Facilitates economic diversification and growth in Ethiopia

Supports cross border electricity trade under initiatives like East African Power Pool (EAPP) ,Ethiopia can export excess electricity

Dam primarily financed through domestic sources - government bonds - not relying on loans from other countries

Africas largest HEP plant ,has potential to reduce Ethiopias energy deficit and support industrialisation

GERD - environmental impacts

-Reservoir behind the dam will destroy a huge area of wilderness impacting on plant and biodiversity

-Methane generation as submerged biomass decomposes in anaerobic conditions

-Pressure of reservoir may create seismic pressure and instigate earth tremors

-Evaporation from the reservoir behind the dam is estimated to cause water loss of 3 billion m3/yr

-sediment starvation downstream (can affect soil fertility)

-alters natural flow of blue nile - could affect downstream Nile delta and Sudanese Sudd ecosystems

What was the purpose of the Colorado River water treaty ?

To fairly share water from Colorado River and Rio Grande between USA and Mexico

When did the Colorado river treaty come into effect ?

1944

What are the advantages of the Colorado river treaty for the USA?

Texan agriculture industry supplied with water

Can control water flow into Mexico - could force mexico to send water

What are the advantages of the Colorado river treaty for mexico?

water supplied for rising population and agriculture

water supplied to regions needing it

Minute 319 allows Mexico to store some of its water allocation in american reservoirs during wet years

Limitations of the colorado river treaty for the USA

Threat to Texan agriculture when Mexico doesn’t fulfil its side of the bargain

Texas heavily reliant on Mexican water

Growing pop and industry requires more water

Infrastructure and treaty needs modernising

Limitations of the colorado river treaty for Mexico

Has to divert water it needs to the US

conflicts between mexican govt and farmers over water use (farmers in Chihuahua using more water than they’re supposed to)

More pressure on water resources due to rising population

treaty needs modernising

Problems with Colorado river treaty

Mexico struggling to fulfill its water delivery to US

In Texas and many other states a lot of water is wasted from leaks - Texas lost 129bn gallons of water in 2022 from leaks

Water scarcity caused closure of Texas sugar industry and puts pressure on citrus industry

Drought in Mexico City - mexico prioritise domestic water (own people)

Suitability of desalination for Israel

repeated droughts

water transfer to Negev desert in south didn’t work - Sea of galilee (lake) vulnerable to drought

developed nation - has the money

technology is rapidly scalable

has a large coastline

limitations elsewhere (ie not Israel) of desalination

reverse osmosis requires lots of energy - lots of emissions from burning fossil fuels

very expensive infrastructure especially if powered sustainably (eg wind/solar)

coastal access

potentially harmful waste products - brine , copper and chlorine

small organisms can get sucked into the desalination plant

How many desalination plants had Israel constructed by 2015?

5

Why has desalination in Israel been successful?

First desalination plant opened in 1970 before worst drought hit

National water system connects desalination plants with consumers

Desalination produces 600 million cubic metres of water a year

Water surplus now gives Israel opportunity to export water

serves as a model for other countries pursuing desalination eg israeli company built desalination plant in california

Examples of water transfer schemes

UK

China South-North water transfer project

where is water transferred to and from in the uk

from wetter , more sparsely populated areas in the north to drier, more densely populated areas in the south

why are water transfer schemes effective in the uk

transfer water from areas of water surplus to areas of water deficit

why are water transfer schemes not always a suitable strategy

not all countries have adequate surplus to supply areas of deficit

expensive infrastructure - not all countries have funding - effective in UK

Advantages of China’s south - north water transfer project

• reducing water insecurity in the north and supporting economic development

• food security is improving as more water is available for irrigation

• health benefits from improved water quality

• improved water supply for the industry

• groundwater withdrawal is reducing

Disadvantages of China’s south - north water transfer scheme

• hundreds of thousands of people displaced by the construction of dams and reservoirs

• ecological damage to the natural environment

• the region is prone to earthquakes, which could cause extensive damage to the scheme

• the project cost a significant amount of money to taxpayers

• antiquities have been lost

• considerable evaporation from canals and reservoirs

Stated aims of the 3 gorges dam

reduce flooding

generate electricity from HEP and reduce use of fossil fuels

allow more cargo ships along river

other aims of the 3 gorges dam

tame the Yangtze river - status and control symbol

show how powerful the Chinese government is

symbol of China’s technological advancements

point of national pride

successes of the 3 gorges dam

generates HEP - less coal burning power stations

created new transport links on river

less air pollution

somewhat reduced flooding

limitations of the 3 gorges dam

not very effective at preventing flooding

about 4million people displaced

much of compensation money embezzeled

urbanisation - loss of farming livelihoods, farmland flooded

more EQ’s and landslides

extinction of animals eg Baiji dolphin

Singapore background

one of the most water stressed countries in the world

heavily dependent on rainfall

limited land for water storage facilities

water rationing implemented 1963 - mock exercises since then

What are the 5 things done to save /make water in Singapore

recycling water (NEWater)

vertical farming

smart monitoring

consumer behaviour

desalination

What is NEWater and what is it used for?

Reclaimed water from drains and sewers

Mainly used in industry and to top up reservoirs in dry months

Potable so some used for drinking

How does vertical farming help singapore grow crops and save water ?

crops grown closer to urban hubs (less food miles)

higher yields

no pesticides used

small amount of water used which is recycled

Drawbacks of vertical farming

significantly increased cost

requires advanced technology

energy intensive

How does smart monitoring help singapore save water ?

only 4.6% of water is lost from leaks and burst pipes in singapore

data sondes with sensors detect any changes then feed this back into a central system so PUB can deal with it by adjusting water flow so less water is lost

How does consumer behaviour help singapore save water ?

Promotes water efficiency messages to the public

water efficiency app - tells people what appliances use the most water and how to reduce water usage

Example of humans disrupting the drainage basin cycle

Brazil / Amazon

Causes of 2014 Brazil drought

Usually , moist air from S Atlantic encounters Andes which force it S creating a flow of moisture round the basin

in 2014 , high pressure systems diverted moist air further N - heavy rain in Bolivia and Paraguay but dry air over Brazil

Impacts of 2014 drought on Brazil

Water rationing for 4 million people

Power cuts - Brazil reliant on HEP

Increased groundwater abstraction

High fees to dig wells led to illegal wells being dug

Arabica coffee bean crop reduced driving prices up by 50%

By 2015 main reservoirs had reached 5% of their capacity

Impacts of drought on the Amazon

rainforests recycle half of their rainfall so deforestation could trigger positive feedback loop causing more drought

drying forest - reduced soil water storage and evapotranspiration , wildfires more likely

prolonged drought causes forest stress - could cause Amazon tipping point

Amazon intakes 20 bn tonnes of water vapour which is mostly released over Brazil as rain

Worldwide impacts of drought in the Amazon

loss of a carbon sink

wildfires

changes to ENSO (el nino southern oscillation)

Importance of the Pantanal

worlds largest tropical wetland area

significant freshwater ecosystem for birds and aquatic life

river floodplain vital and relies on seasonal rainfall

during seasonal rainfall 80% of pantanal is flooded

Impacts of 2014 drought on pantanal

increase in tree mortality - reduced habitats

more wildfires (routine grass burning by cattle farmers)

What are 3 contrasting drainage basins

Amazon

Yukon

Indus

Features of Amazon hydrograph and why

massive lag time

lots of vegetation - high interception - less surface runoff

Features of Yukon hydrograph and why

long lag time - delayed peak due to snow formation

surge in discharge in spring and summer - rapid snowmelt

permafrost - reduced infiltration - more surface runoff

Features of Indus hydrograph and why

bimodal flow pattern - 2 peak discharges

Peak 1 - spring - long lag time - snowmelt from himalayas

Peak 2 - summer - short lag time and higher peak discharge - monsoon season