3.6 - Water Flashcards
Precentage of freshwater on Earth and its sources
2.5% of water is freshwater
* stored in glaciers and ice sheets or as groundwater
Main sources of water (5)
- Lakes and rivers
- Aquifers
- Reservoirs
- Desalinisation
- Rainwater harvesting
Groundwater as a supply of water (explain)
Water stored underground that has filtered through soil and rocks
* It is obtained by drilling boreholes or digging wells.
* When all the rock is fully saturated with water it is an aquifer.
* Groundwater may also come to the surface as a spring
Issues with groundwater as a water supply
- Overuse or over abstraction of water in some areas means that aquifers do not have time to recharge through precipitation
- Pollution from industry, agriculture and domestic waste can leach into the groundwater
Surface water as a water supply (explained)
Water which is stored in the lakes, reservoirs and rivers.
Surface water as a water supply issues
- Pollution from industry, agriculture and domestic waste can enter the water system through surface run off
- Dams are used to store water in reservoirs, but the construction of dams has slowed due to lack of suitable sites and concerns regarding the environmental impact
Desalinisation as a source of water (explained)
The removal of salt from sea water to mean that it can be used for domestic, agricultural and industrial purposes
Desalinisation as a water supply issues
Expensive to set up and run - they use a lot of energy
Global water use by sector (3)
- 70% agriculture - irrigation of crops and water for livestock
- 20% industry - producing goods and generating energy
- 10% domestic - toilets, cooking, cleaning, washing
Why is water demand higher in MEDCs than LEDCs? (name 3 reasons)
- Improving living standards - people have more appliances/sanitation which use water
- Increased use of water in leisure and tourism - water parks, golf courses
- Increased urbanisation
- Increasing industry - water is needed for the production of goods and energy production
- Increasing use in agriculture - more water is needed for livestock
Water stress
Water stress occurs when the supply of water is below 1700m3 a year per person
Water scarcity
Water scarcity is when the supply is below 1000m3 a year per person
Causes of water shortages (name 3)
- Low percipitation throughout the year or drought
- Demand is greater than supply due to increasing population
- Issues with abstraction in rivers - large amounts of water are taken from the upper course reducing the amount that reaches the lower course
- High temperatures can increase evaporation and reduce water availability
- Type of land use - agriculture leads to increased water consumption
Impacts of water shortages (name and explain 3)
- 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 in the industrial sector of MEDCs
Most water in MEDCs is used for industry. Some of this water could be recycled and used again within the process to reduce consumption
