✅ 3.2.5.3 RESOURCE SECURITY - Water Security Flashcards
Agricultural uses of water
Farming - Farms use water to irrigate crops and raise livestock.
Industrial uses of water
Steam generation, washing, cooling
Often creates wastewater, has to be recycled
What % of water withdrawals are for domestic use
11%
Higher in HICs w/ high rainfall like UK
Low in most other countries, especially LICs
What is India’s agricultural water use
Largest in the world at 700 billion m^3 / year
Growing rapidly, doubling from 1975 to 2010
What % of freshwater withdrawals are for agriculture globally, in HICs and LICs
70% globally
90% for LICs
41% HICs
Which countries all irrigate over half of their agricultural land
Pakistan, Bangladesh, South Korea
(warmer poorer countries who therefore must rely on agriculture, so need to abstract more water for irrigation)
What % of total water withdrawals are for industrial purposes?
19%
What % of total water withdrawals are for industrial purposes in LICs?
2% (is much greater usually in HICs)
What is the US’s industrial water use
300 billion m^3 / year
Largest in the world
China 2nd largest at 140
Which country has the highest per capita water demand
USA - 6.8 tons / day
How many river basins in the world are transboundary
276
What is an artesian aquifer?
an aquifer between impermeable rock
therefore water doesn’t escape
is recharged where it makes contact with the surface
Water stress
When demand for water exceeds supply, or when water is not of high enough quality to use, places experience water stress.
Under 1,700 m^3 pp annually
What level of water per person is water scarcity
What countries have water scarcity
Under 1,000 m^3 pp annually
South Africa, Iraq
What level of water pp is absolute water scarcity
What regions have absolute water scarcity
Under 500 m^3 pp annually
North Africa
What level of water pp is Physical water scarcity
What regions have physical water scarcity
Less than 500mm of rainfall a year
Middle East, N Africa
What is economic water scarcity
When a pop. does not have the monetary means to access enough water
South America, South Africa
What does the UN define water security as?
The capacity of a nation to safeguard sustainable access to adequate quantities of acceptable quality water
Physical factors which affect water supply
Climate
Geology
Drainage
How does geology in Thames Basin affect water supply
Chalk in the Thames Basin acts as an aquifer, provides base flow
How does climate affect water supply in Thames Basin
690mm / year (UK average is 900mm)
Thames basin classed as suffering severe water stress.
During winter groundwater stores are replenished
Not much water available for natural environment
How does drainage in Thames Basin affect water supply
Thames Basin supplies 80% of London
Majority of this is from ground water from acquifers
Impact of unclean water on children
340,000 children under 5 die every year from unsafe water use
How many use a drinking water source contaminated by faeces
2 billion
How many lack access to basic drinking-water services
785 million
10% of the population
How does water contribute to public health
SDG 6 aims for global accessible clean water as it is essential
Access to clean water means cleaner facilties, less spread of diseases like Cholera
Safety for women and children who sometimes have to travel far to collect water in some poorer places
Clean water means safter crops, clean waterin irrigation used
Lack of accessible clean supply means using unclean surface water supplies
Strategies to increase water supply
Desalination
River Catchment Scheme, e.g Dams
Transfer scheme
Boreholes, Groundwater
Sources of water
Surface water
underground water
seawater
What is a borehole
Drilling down nto ground to a borehole, to make a well, to access groundwater supplies
Pros of boreholes
Groundwater is available year round
Cons of boreholes
Can deplete groundwater stores faster than they recover
Can cause subsistence
Water has to be cleaned
Salt water intrusion intogroundwater as aquifers recharge
Rivers dry up
What does desalination involve
Obtaining potable water from seawater
Via reverse osmosis (through a partially permeable membrane)
Distillation (extracts water vapour, condenses it)
What are cons of desalination
Expensive- plants cost up to $2.9 billion
Can damage fisheries as ocean water intake pipes suck in and kill marine life