5.9 managing water supply

Question 1

9a) types of hard engineering

Answer 1

1. water transfer schemes
2. mega dams
3. desalination

Question 2

9a) water transfers (how do they help, examples, + and -‘s)

Answer 2

provide freshwater to those in need of a supply buy transferring it from areas with adequate/surplus stores

EG
Chinas North- South Water Diversion: mixture of tunnels, canals and pumping station
total of 300-450km long
largest transfer project in the world
—- ADVANTAGES
more water available to the arid north
(44.8 billion m3 of water transferred annually)
stops over abstraction of aquifers in the north: allowing them to be recharged (800mill m3)

—- DISADVANTAGES
expensive N-S cost $79 BILLION
- downstream countries eg Thailand, India etc at a loss

Question 3

9a) mega dams (how do they help, examples, + and -‘s)

Answer 3

control flow of water to maintain freshwater supplies in reservoirs created

EG
Three Gorges Dam (2003)
the GERD
there are 900,000 dams in China (46% of global dams)

—- ADVANTAGES (3 gorges dam)
increases shipping capacity
reduces CO2 emissions by 100 million tonnes per year (replacing coal fired plants)
controls downstream flood risk
—- DISADVANTAGES
1.3 million people displaced
sedimentation build up upstream, more erosion downstream, increased risk of landslides

Question 4

9a) desalination (how do they help, examples, + and -‘s)

Answer 4

extract salt from sea water (reverse osmosis)

EG
there are 1400 plants in the world
top nations: Saudi Arabia, UAE, USA, Spain, China

—- ADVANTAGES
price declines by 10% every year
produces high quality freshwater, no extra processing needed
unlimited supply of sea water

—- DISADVANTAGES
needs to be by the sea
requires huge amounts of energy
high tech and expensive
salt waste product is dumped back into sea: killing marine life, potential to have knock on effect for surrounding ecosystems

Question 5

9b) aims of sustainable water management

Answer 5

• minimise wastage and pollution of resources
• ensure safe affordable access for all people
• take into account of all water users
• guarantee an equitable distribution within and between countries

Question 6

9b) types of sustainable water management

Answer 6

1. rainwater harvesting
2. smart irrigation ( traditional sprinklers and surface flow systems replaced with modern spray technology and drip irrigation systems
3. recycling grey water ( for agricultural use)
4. water conservation (re- education on domestic uses of water, how individuals can reduce consumption)
5. hydroponics ( growing crops in greenhouses: drip fed nutrients and water in a shallow tray: no soil!!)

Question 7

9b) c/s Singapore and sustainable water management

Answer 7

circumstances:
few natural water resources, thriving economy, high standard of living and high per capita water consumption… water management is a top priority!!

three strategies:
- collect every drop of water
—- gov has various ways to encourage citizens to save water. since 2003 per capita domestic consumption has fallen from 165- 150 litres of water per day

• re- use water endlessly (new technologies!!)
• desalinate more sea water
  —- two plants now meet 25% of water demand

however Singapore still has to import water from Malaysia

Question 8

9c) aims of integrated water resources management

Answer 8

based on achieving a close cooperation between basin users and players. basin is treated holistically in order to ensure three things:
- environmental quality of rivers and catchment
- water is used with maximum efficiency
- equitable distribution of water among users

experience has shown this works well at community level but not so well in larger basins (esp if international boundary is involved

Question 9

9c) potential for water wars (role of players)

Answer 9

in spite of potential for conflicts over shared waters, international cooperation is the rule rather than the exception.
—- in past 60 years military conflict has occurred only in a handful of drainage basin disagreements

players involved in tensions and conflicts over water can play a part in reducing the conflict risk…

—- global scale: UN sets rules which governments are required to observe
NGOs eg World Wide Fund for Nature have a vital role to play in a ‘neutral’ monitoring of potential conflict situations.
—- local scale: range of players from planners to environmentalists to water companies and users.

!!!!each has a responsibility to minimise conflict and maximise cooperation!!!

Question 10

9c) water sharing treaties: important international agreements

Answer 10

• Helsinki Rules: ‘equitable use’ and ‘equitable shares’ concepts
• UNECE: promotes joint management and conservation of shared freshwater ecosystems
• UN Water Courses Convention: offers guidelines for the protection and use of trans boundary rivers
• EU Water Framework: (2000) commits all members to ensure the ‘status’ of their water bodies, including it their marine waters up to one nautical mile from shore

Question 11

9b) water conservation (how does it help, examples, + and -‘s)

Answer 11

water metres given to households
not growing crops that are water thirsty and importing them from countries not experiencing water stress
vertical farming!!! (uses 95% less water through special misting technique, can be built in cities, but still in early stages of development)

EG
Isreal- recycle grey water for agriculture (65% of crops)

—- DISADVANTAGES
very small scale and individual, requires huge logistics to try and upscale

Question 12

9b) rainwater harvesting (specific example, + and -‘s)

Answer 12

NORTHERN CHINA: 60% rainfall between July and Sept (uneven
rural populations came up with a solution called the 1-2-1 project: family provided with 1 tiled roof and 2 water tanks to gather enough crops for 1 field (roof gutters direct rainwater to underground water cellars)

—- ADVANTAGES
bottom up, low tech and cheap solution
—- DISADVANTAGES
only appropriate for this situation, not applicable for commercial farming