Water security Flashcards
1
Q
Components of demand
A
- Agricultural (crop irrigation and livestock care)
- Industrial (water used as a coolant for heating steam turbines or processing operations such as textiles and food processing)
- Domestic (household and public/municipal)
2
Q
Water stress
A
- Demand exceeds the available amount of clean, non-polluted water during a certain period.
- Leads to over-exploitation of long-term water stores such as aquifers.
- Quality of available water decreases due to eutrophication.
- Renewable water in a country decreases to less than 1700m3 per capita
3
Q
Supply of water cannot meet demand because :
A
- Aquifers are being over-exploited
- Water is being utilised in long-term stores, faster than it is recharged
- Climate change is causing extended drought periods
- Water tables are decreasing
4
Q
Demand for water has increased due to :
A
- Population Growth = More people requires more water
- Socio-Economic Factors
- Growing middle class population
- Development
- Greater demand in industry and agriculture
5
Q
Relationship of water supply to climate : Global precipitation
A
- estimated to be 860mm per year
- 77% falls over oceans and 23% on land
- for land based fresh water supply to be maintained there needs to be reliable and adequate annual rainfall : may be seasonal but storage can level out these differences
6
Q
Relationship of water supply to climate : Temperatures
A
- High temperatures lead to high rates of evaporation, which can mean inputs of precipitation are lost to the atmosphere before they impact on water supply
- Where the climate is cooler and less windy there will be lower rates of evaporation
- Where climate is characterised by very low (sub-zero) temperatures there will be freezing for long periods of time and fresh water supplies will be inaccessible until a seasonal period of thawing
7
Q
Relationship of water supply to climate : Seasonal changes
A
- Balance between precipitation and evapotranspiration will affect underground water supplies
- In winter, where then there is more precipitation, this will lead to a surplus and rising levels of underground water resources, reverse in summer
8
Q
Relationship of water supply to geology
A
- Affects the location of reservoirs
- Impermeable rock will ensure water is not lost due to seepage and rocks must be stable as faulting and movements will destroy or damage dams
9
Q
Relationship of water supply to drainage
A
- Drainage basin is the area drained by a river and its tributaries
- Receives inputs of precipitation and the outputs include channel runoff, evapotranspiration and groundwater flow
- Operation of the drainage basin system is determined by local physical factors such as climate and geology
- relationship between the inputs and outputs will determine the water supply
10
Q
Methods of increasing water supply : Storage
A
- Constructing dams to raise upstream water levels and create reservoirs
- Dams may be temporary, which are raised in the wet season to store water that can be used for irrigation during the dry season
11
Q
Methods of increasing water supply : Diversion
A
- Water is moved from one area to another, within the same drainage basin
- This can provide water for cities, or irrigation for fields
- Can have significant environmental impacts e.g overabstraction
12
Q
Methods of increasing water supply : Desalination
A
- Converting sea water into freshwater for drinking
- High energy demand, but is a viable in desert countries where other options don’t exist
- Expensive due to the advanced technology
- Causes environmental damage if it sucks marine life and may pollute other groundwater
- If solar or wind energy was used to power a plant, it would be a more sustainable option
13
Q
Methods of increasing water supply : Catchment
A
- Wetland restoration improves supply and quality of the water by filtering the water
- Afforestation can have similar benefits and helps to create important wildlife habitats
- Blocking drainage channels
- Farmers shifting to arable farming to reduce runoff and increase infiltration
- Potentially the most sustainable method of increasing water supply as it aims to restore the natural environment through rewilding
14
Q
Strategies to manage energy consumption : Reduce domestic wastage
A
- Installation of water meters
- Low flush and dual flush toilets
- Encouraging the use of showers and not baths
- New technology to save water in domestic appliances
- Collecting rainwater to use in gardens
- Push button taps and tap restrictors
15
Q
Strategies to manage energy consumption : Reduce Agricultural use
A
- Drip-feed irrigation, which delivers water to the plant base
- Rain sensors, which shut down irrigation systems when it rains
- Digging boreholes to water-bearing rock
- Contour ploughing to reduce runoff
- Increase the percentage of organic content in soils as this retains wate
- Collection and recycling of water
