Water Shortages (Cambridge (CIE) O Level Geography)
Revision Note
Author
Bridgette BarrettExpertise
Geography Lead
Water Shortages and Management
Water shortages (deficit)
Many areas of the world have water shortages (deficits)
Water deficit can be due to:
Low supply - lack of precipitation, high levels of evaporation, poor water management, drought, pollution
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
South- west USA
East Brazil, parts of Argentina and Chile
India
They tend to be areas around the Tropic of Cancer and Tropic of Capricorn
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
There are two types of water scarcity:
When physical access to water is limited due to the climate conditions of the area. This is physical water scarcity
When a population does not have the money to utilise the available water resources. This is economic water scarcity
The UN Millennium Development Goals included goal 7 ' Halve by 2015, the proportion of the population without sustainable access to safe drinking water and basic sanitation'
This goal was not met but access to clean water has improved
In 2020 74% of the world population now have access to clean water supplies
In some areas there may be water supply, but this is not potable
UNICEF estimates 2.2 billion people do not have access to potable (clean drinking) water
Around 4.2 billion people do not have access to safely managed sanitation services
Water scarcity is expected to increase across the world due to:
Increasing population
Development increases demand
Climate change increasing aridity
Pollution
Causes of water shortage
Many of these areas have a deficit due to low precipitation throughout the year or drought
Demand is greater than supply in some countries due to increasing population, industry and agriculture
In some areas rivers flow through many countries and this leads to issues with water abstraction and other activities. The upstream country may
Take large amounts of water from the river for agriculture, industry or domestic use leaving less for the country further downstream
Build dams or alter river flow which impacts on discharge downstream
Reduce water quality by introducing pollution to the river
Higher temperatures may lead to increased evaporation and transpiration reducing the amount of water available
The type of land use - agriculture leads to increased water consumption
In some countries there is disparity in water supply between areas - China has severe water shortages in the north but water is more available in the south
Conflict - many of the LEDCs who have struggled to meet the MDG are experiencing conflict
Impacts of water shortage
There are many impacts of water shortages including:
Death and illness due to water-borne diseases such as cholera and dysentery
Potential for conflicts over water supply particularly where countries share a river basin
Children in rural areas in LEDCs often miss out on school as they are responsible for collecting water (may have to walk miles to the nearest water source)
Lack of food due to:
Crops cannot be irrigated and so yields are lower
Livestock dies due to a lack of water
Damaged ecosystems and loss of habitats
Affects economic development as water is not available for industry
Managing water supply
There are many ways in which water supply can be managed but this is easier in MEDCs where the money to implement these schemes is available
Water Use | Management to Reduce use |
---|---|
Industry | Most water in MEDCs is used for industry. Some of this water could be recycled and used again within the process to reduce consumption |
Agriculture | Drip irrigation which delivers water to the roots of plants. Irrigation leads to 40% of the water used being lost to evaporation and poor management. Drip irrigation reduces this loss significantly |
Domestic | Water efficient appliances Rainwater collection Use of grey water for washing cars and watering plants Low flush toilets and water saving shower heads Water companies fixing leaks and improving efficiency |
In LEDCs water management is more difficult due to lack of funding
The involvement of Non-Governmental Organisations (NGOs) such as Water Aid helps to fund projects
Appropriate technology is essential to manage water in LEDCs, they include:
Wells
Gravity fed systems where water is piped from a spring or river higher up a valley
Boreholes use a hand pump to bring water to the surface
Rainwater collection from roofs
Drip irrigation
Drought resistant crops
Exam Tip
Remember when interpreting maps you need to pay close attention to the key and title.
In the above example the map shows both surplus and deficit of water supply on a sliding scale. Areas of greatest water surplus are dark blue and areas of greatest water deficit are dark orange.
Case Study: Spain
The average precipitation in south-east Spain is approximately 365mm a year
Most precipitation occurs in winter
The area is one of the driest in Europe
Agriculture uses 80% of the water available
147,000 hectares of land require irrigation
Regular droughts mean the supply of water is further reduced
There is a water deficit as demand exceeds supply
Tourism increases the problem:
Water parks and golf courses use significant quantities of water
An average tourist uses between 450-800 litres per day
An average Spaniard uses 127 litres per day
Tagus-Segura Project
Completed in 1978
60% of the water flowing into the Tagus is transferred
A 286km pipeline which connects for Spanish river basins Tagus, Jucar, Segura and Guadiana
The aim was to supply Alicante, Murcia and Cartagena in the south-east to reduce the water deficit
Tagus-Segura Project
Issues
Much of the water transferred went to the tourist and leisure users not to small scale farmers
Water consumption in the south-east increased due to an increase in supply
It is estimated that 15% of the transferred water is being illegally used by leisure users such as golf courses
Large commercial farms are benefitting more than small scale farmers
Ebro project
A second water transfer project was proposed in 2001 to transfer water from the River Ebro
This project was abandoned due to:
The failure and issues with the Tagus-Segura project
The cost
The threat to the Ebro delta as the scheme would have disrupted sediment flow to the delta
Spain has now moved to utilising desalinisation plants to meet the demand for water
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