Water (AQA GCSE Geography)
Revision Note
Written by: Bridgette Barrett
Reviewed by: Jenna Quinn
Global Distribution of Water
Water is essential for life but only 2.5% of water on Earth is freshwater
Sources of water
It is used in all aspects of life for domestic use, agriculture, industry and energy
Global water use by sector is:
70% agriculture: irrigation of crops and water for livestock
20% industry: producing goods and generating energy
10% domestic: toilets, cooking, cleaning, washing
The use by sector varies across countries depending on whether they are HIC, NEE or LIC
Water supplies are not evenly distributed across the globe
Factors affecting supply
Climate: the amount of precipitation, rates of evapotranspiration and changes in climate affects the water available
Geology: affects where aquifers and groundwater are located and how much water is stored
Rivers: where they flow affects the availability of water
Pollution: 80% of waste water is untreated this impacts on the water quality and whether it is safe to use
Over-abstraction: reduces the available stores of water
Infrastructure: pipes and canals used to transfer water, water treatment works and pumping stations are all expensive and many LICs lack infrastructure particularly in rural areas due to the cost. Even in HICs and NEEs remote and rural areas may not have the infrastructure needed to supply water
Poverty: lack of money means that people cannot afford a clean water supply or bottled water
Water security
To be water secure is to have a clean, reliable source of water
A place or country that does not have this is water insecure
Water surplus
Areas of water surplus (where the supply of water is greater than the demand) may be the result of:
High supply: high precipitation, low evaporation rates, effective water management
Low demand: low population, effective water management, low temperatures
A combination of high supply and low demand
Areas with a surplus include:
North-east Brazil in the Amazon rainforest
Canada and parts of north USA
Russia
Water deficit
Areas of water deficit (where the demand for water is greater than the supply) may be the result of:
Low supply: lack of precipitation, high levels of evaporation, poor water management
High demand: increasing population, industry and agriculture
A combination of low supply and high demand
Areas with the greatest water deficit include:
Australia
North, East and South Africa
Middle East
West USA
Parts of South America
India
Water surplus and deficit
There are different levels of water shortage: these are water stress and water scarcity:
Water stress occurs when the supply of water is below 1700m3 a year per person
Water scarcity is when the supply is below 1000m3 a year per person
Reasons for increasing water consumption
Water consumption is increasing across the world
Global freshwater use
Population growth: there are now over 8 billion people
Each person requires about 2 litres of clean drinking water a day to remain in good health
In addition 18 litres per person is needed for things like sanitation and cooking
As well as an increase in domestic water demand, population growth also increases the use of water for:
Energy production
Agriculture
Industry
Economic development: as countries develop the demand for water increases because:
People have more items which use water such as dishwashers, toilets and showers
Industry increases and factories use large quantities of water
Intensive agriculture is needed as people eat more food, and irrigation systems use large quantities of water
As more people move to urban areas the demand for water for drinking and sanitation increases
Worked Example
Describe the distribution of countries which had 76-90% access to basic drinking water services as shown in Figure 1.
[2 Marks]
Answers should make use of Figure 12 through naming countries and affected areas in order to describe the pattern and should be focussed on the 76-90% category
Answer:
One mark for a basic statement, e.g.
Nearly all on the coast [1]
The biggest area is Southern Africa [1]
Apart from one group of 3 they are all isolated [1]
4 out of the 8 are in Western Africa [1]
Second mark may be a second separate point or developed point for further descriptive clarity, e.g.
Nearly all on the coast [1] except Botswana (d) [1]
The biggest area is Southern Africa [1] with the 3 largest countries in the category all next to each other (d) [1]
Apart from one group of 3 they are all isolated [1] and quite evenly spaced along the central and western coastline (d) [1]
4 out of the 8 are in Western Africa [1] with the other 3 all grouped together on the southern tip of Africa (d) [1]
You would receive no marks for description of any categories other than 76-90%.
No credit for explanation
Impacts of Water Insecurity
Water insecurity has the greatest impact on LICs and NEEs
Lack of water treatment, infrastructure and waste disposal means that water supplies are:
Polluted by industrial waste: where there are laws about waste disposal these are often not enforced
Agricultural pollution due to increasing use of pesticides and fertilisers
Domestic waste and sewage often get into the water supply
Approximately 2.2 billion people lack access to safely managed water and 4.2 million lack safely managed sanitation
Health impacts
This leads to:
Spread of waterborne diseases such as cholera, typhoid fever and dysentery
Diarrhoea (one of the most common effects of waterborne disease) which leads to the death of more than 0.5 million children a year
Unsafe water leads to 1.2 million deaths a year
Fall in income as people are unable to work due to illness
Death Rate per 100,000 people due to unsafe water sources
Agriculture
In areas of water insecurity irrigation will have to be reduced or may not be possible leading to:
A reduction in yields
Crop failure
Food shortages
Food price increases
Industry
Industries use large quantities of water when this is not available this leads to:
A decrease in production
Loss of income for businesses and countries
Interruption of energy supplies as electricity production may also rely on water supplies for cooling or hydroelectric power
Conflict
At least 60% of the world's water sources: rivers and aquifers: cross a boundary between countries
The actions in one country can have significant impacts on countries and regions downstream, including:
Over-abstraction
Construction of dams and reservoirs
Pollution (sewage, industrial and agricultural waste)
Mismanagement of water sources can cause conflict between neighbouring countries and regions
The construction of the dams on the Tigris and Euphrates rivers in Turkey has significantly affected water flow into Syria and Iraq
During the filling of the Ilisu Dam in Turkey in 2019 the water flow into Iraq decreased 50%
The quality of the water was also affected: in Basra people's health was severely affected with an increase in rashes, diarrhoea and vomiting
On the border between India and China there have been clashes between communities due to concerns that China was reducing water flow into India
Worked Example
Outline one or more likely impacts of water insecurity.
[3 Marks]
Answer:
Conflict may increase [1] between regions or countries who share a water supply as they wish to secure control [1]
Food production/yields may decrease [1] because it is harder to find the water to irrigate crops [1] so they may not grow so well [1]
Manufacturing output may decrease [1] as water intensive industries can’t produce so much [1] which can impact on the country’s GDP [1]
Disease may increase in poorer countries [1] as insecure supply means people are forced to drink polluted water [1]
Strategies to Increase Water Supply
Increasing demand requires increasing water supply which can be achieved in a range of ways
Increased storage and diversion of supplies
Dams and reservoirs
Desalination
Water transfer
Table Showing Advantages and Disadvantages to Strategies to Increase Water Supply
Method | Example | Advantages | Disadvantages |
|---|---|---|---|
Water diversion and storage | Arizona in south west USA stores 600 million m3 water underground |
|
|
Dams and reservoirs | Three Gorges Dam in China Ilius Dam in Turkey |
|
|
Desalination | Alicante II Seawater plant in Spain Tampa Bay Water plant, USA |
|
|
Water transfer | Wales to England, UK South North Water Transfer project, China Tegus-Segura, Spain |
|
|
Example Case Study: South North Water Transfer Project, China
River management in China
The average precipitation in north-east China is approximately 200-400mm a year
Most precipitation occurs during the brief wet season
Average rainfall has steadily decreased since the 1950s
The main industrial areas and regions of economic growth are on the North China Plain around Tianjin and Beijing
The main water source for the area has been groundwater:
Demand for water in Beijing alone is 3.6 billion cubic meters
Supply of freshwater in Beijing is 3 billion cubic meters
There is a significant water deficit
The over abstraction of groundwater has led to subsidence in some areas of the city of 11cm
South-north water transfer project
Aims to transfer 12 trillion gallons of water a year from the south of China to the area around Beijing
Central section was completed in 2014
Final completion estimated to be in 2050
It will link China's four main rivers: Yangtze, Yellow, Huaihe and Haihe
Advantages | Disadvantages |
|---|---|
Water is being supplied to industries and to irrigate large scale farms for food production | By 2014 US$79 billion had been spent |
Reduces water insecurity in the north-east | Many people have been relocated for construction of dams, reservoirs, pipes and canals |
Reduces the abstraction of groundwater | In some areas in the south people's water use has been restricted to ensure that there is sufficient to transfer |
Improved water quality | Recent droughts in the south have reduced the amount of water available |
Three Gorges Dam
Constructed between 1994 and 2012
Advantages | Disadvantages |
|---|---|
Provides 10-14% of China's electricity through hydroelectric power | Over 1.3 million people forced to move due to the flooding of the valleys |
Allows ships to navigate further up the river improving trade | Many cultural sites were lost |
Reduces the severity of flooding downstream | Increases the risks of landslides |
The reservoir provides water for irrigation | Cost US$37 billion |
Reduces reliance on fossil fuels | Sediment is building up behind the dam and reduces sediment downstream |
Sustainable Water Supply
Sustainable water supplies:
Do not cause harm to the natural environment
Benefit local communities
Reduce waste
Can be used globally
Water Conservation
Involves reducing waste and using water less
Reduce leaks: it is estimated that globally 45 million m3 of water is lost per day through broken pipes and other leaks
Education: to inform people why water conservation is important encourage people to use and waste less
Water meters: reduce water use as people pay for the water they use and so tend to waste less
Water efficient appliances: shower heads, low flush toilets and water efficient washing machines, dishwashers all use less water
Reduce pollution: pollution means that water cannot be used
Efficient irrigation: drip irrigation reduces the amount of water lost through evaporation
Groundwater management
Groundwater is the water stored underground in aquifers
These can be affected by:
Over abstraction
Pollution
Sustainable management of aquifers includes:
Maintaining a balance between water abstraction and recharge (either natural or artificial from rivers and lakes)
Monitoring water tables and quality
In HICs groundwater is usually carefully monitored and managed: although in some areas such as California there is increasing concern that over abstraction is resulting in the aquifers being severely depleted
In LICs and some NEEs water pollution and over abstraction are common leading to exhaustion of aquifers in areas such as the Sahel in Sub Saharan Africa
Recycling
Waste water from industry and domestic use which is treated so that it can be reused
Grey water
Grey water is the term used to describe domestic waste water
This can be used both inside and outside the home in any situation where drinking water quality is not required, including:
Flushing the toilet
Watering the garden
Cleaning car
Worked Example
Explain how different strategies can be used to make water supplies more sustainable
[6 Marks]
The command word in this question is 'Explain'
You need to outline different strategies of sustainable water supply
It is not enough to say 'reduce water waste', you need to explain how this makes water supplies more sustainable
This is a levelled answer, so marks are awarded for the answer overall rather than for individual points
In a level 2 and 3 answer you are expected to use geographical terms and include examples of at least two strategies: from water conservation, groundwater management, recycling, 'grey' water
An example of an answer for each level can be seen below
These are just examples and there are many others which can be found in the mark scheme: see topic question 3e
Answer:
Level | Marks | Exemplar Answer |
|---|---|---|
1 (Basic) | 1-2 | Grey water is water from homes that has been used in the home to water the garden. This reduces the amount of clean water used. |
2 (Clear) | 3-4 | A sustainable water supply is achieved by providing people with safe water now and in the future. One strategy would be use of grey water systems. These can be used in homes to use waste water for watering the garden. Another strategy is water conservation ensuring that water is not lost through water leaks. |
3 (Detailed) | 5-6 | A sustainable water supply means meeting the water needs of people today whilst ensuring that future generations can meet their needs for safe water. There are a range of ways in which this can be achieved. Grey water systems take waste water from the home (sinks and dishwashers), filter it and then it can be used on the garden. This reduces the use of clean water. Another strategy is water conservation which involves reducing waste by fixing leaks and more efficient irrigation such as drip irrigation. It also involves using water efficient appliances and water meters to reduce water use. These all ensure that more clean water will be available to meet people's needs now and in the future. |
Example Case Study: Shinja, Zimbabwe
Background
The Shinja resettlement area suffers acute water shortages
The community only had shallow wells
Which dry up a few months at the end of the rainy season
This led to issues with sanitation and hygiene
Scheme
Elephant pumps were installed in a number of communities
The pumps are inexpensive to make and repair
Made from local materials
They are enclosed which reduces contamination
Impacts
Water and sanitation diseases such as diarrhoea and bilharzia decreased
Vegetable growing and livestock rearing increased
Reduced the potential for conflict with neighbouring communities
Time taken to collect water was significantly reduced
Food intake increased and was of better quality
Attendance at school increased as children were not involved in water collection
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