Water Security 2

Question 1

Describe what happened to the Aral Sea in the 1960’s

Answer 1

Soviet Union diverted the Anna Dairyer and the Sydronyia (two rivers which fed into the Aral Sea) for a mass irrigation project to grow cotton in the desert

By 2007, it had declined to 10% of its original size - now mostly desert

Question 2

Give some effects of the shrinking Aral Sea

Answer 2

The region’s once prosperous fishing insustry has essentially been destroyed - unemployment + economic hardship

Retreat of the sea has caused local climate change - summers becoming hotter and drier and winters colder + longer

Decades of heavy irrigation has brought the water table to the surface - making drinking water and food to salty + polluted

Question 3

Outline 3 strategies to increase water supply

Answer 3

Catchment and Storage

Diversion and Inter-basin transfer

Desalination

Question 4

Explain Catchment and Storage as a strategy to increase water supply

Answer 4

LARGE SCALE

• Interrupting and storing the flow of water via dams and reservoir schemes
• Can be multi-purpose: HEP, tourism, fishing

SMALL SCALE
- Rainwater harvesting

Question 5

Give some examples of Catchment and Storage

Answer 5

Three Georges Dam - largest in world

Lake Nasser Dam - Egypt

Small scale = Bangalore, India. Rainwater system compulsory in buildings over a certain size

Question 6

Give pros and cons of Catchment and Storage

Answer 6

CONS

• Zero sum game. One group may benefit at the expense of another
• Changes river regime downstream - sedimentation over time reduces capacity

PROS
- Can be multi-purpose

• Relatively cheap, can lead to water self-sufficiency (Small scale)

Question 7

Explain Diversion and Inter-Basin Transfer as a strategy to increase water supply

Answer 7

River diversion is used to transfer water form one river catchment to another when there is a surplus of water in one area, and too little in another

Water is drawn from rivers, reservoirs and aquifers, and pumped across the region, enabling localised droughts to be tackled quickly

Question 8

Give anexample of Diversion and Inter-basin transfer

Answer 8

China intends to build the South-North Water Transfer project

This would divert 44.8 billion m3 of water per year from the Tonytbe River, to the Yellow River

Question 9

Give some pros and cons of Diversion nd Inter-Basin Transfer

Answer 9

CONS
- Were plans to divert Western Water to S.E England, but abolished due to construction costs, ecological concerns and public resistance to move

• China’s project relocation is exacerbating social inequalities - making the North richer

PROS
- Helps drought affected regions quickly and effectively

Question 10

Explain Desalination as a strategy to increase water supply (Two Ways)

Answer 10

REVERSE OSMOSIS
- Involves filtration of seawater at high pressures through a partially permeable membrane, using small polymeric tubes to convert it to potable water. Collects freshwater, and rejects very saline water which is pumped back to sea

DISTILIATION
- Water is boiled by heating under reduced pressure to save energy - The steam produced is condensed and collected separately whilst the salt is left in the boiler

Question 11

Give some examples of Desalination plants

Answer 11

Generally developed in wealthy countries with water stress: Saudia Arabia, Oman, UAE

Thames Water’s Desalination plant at Brecon provides water for over 400,000 homes through reverse osmosis

Question 12

Give a pro and con of Desalination

Answer 12

CONS

• Expensive and not considered sustainable because it is very energy intensive + a significant source of greenhouse emissions.
• Would still need to transfer it via Inter-Basin transfer to reach affected areas

PRO
- Provides a huge new supply of water

Question 13

Give two agricultural ways of managing water demand

Answer 13

Irrigation scheduling: prevents farmers from over-irragating - linked to controls and subsidies for groundwater pumping

Mulching: covering soil with protective plastics to prevent water evaporation nd keep temperature constant

Question 14

Give two industrial ways of managing water demand

Answer 14

Power industries replace traditional water cooling systems with air cooling ones

Water pressure reduction - reduce pressure in pipes, thereby reducing losses from leaks

Question 15

Give two domestic ways of managing water demand

Answer 15

Wastewater reuse - reuse treated municipal and industrial water as municipal public and industrial cooling water

Shower-heads and taps - installation. of water-efficient shower-head and taps with aerators and pressure controls to keep water flow at desired levels

Question 16

Explain Partial Root-Zone Drying as a strategy to manage water consumption

Answer 16

• One side of the plant given drip irrigated water, whilst the other side of the plant/root are deprived of water
• Makes plant think its in a drought - closing its stomata, reducing ater loss through transpiration
• However, because one side is still being irrigated there’s no water stress. Can cut water usage by 50% whilst maintaining/slightly increasing crop yields

Question 17

Give 5 sustainability issues linked with water management

Answer 17

Virtual Water Trade

Water Conservation

Recycling water

Grey water

Groundwater management

Question 18

Explain virtual water trade

Answer 18

Refers to the total requirement of water for a commodity/manafactured product that is subsequently exported

Producers = exports of virtual water

Water scarce nations can avoid producing ad exporting water intense products

Question 19

Give two examples of the Virtual water trade

Answer 19

One steak = 4650 litres

Kenya growing flowers for UK supermarkets in times of drought

Question 20

Explain Water conservation

Answer 20

Reducing water losses e.g through leakage/evaporation

Also about reducing consumption

Question 21

Give an example of Water conservation

Answer 21

California - 96 million shade balls released in lakes to prevent evaporation ($250 over 10 years)

Environmentally damaging

Question 22

Explain Recycling Water

Answer 22

Former wastewater sewage that has been treated to remove solids and certain impurities, and is then allowed to recharge the aquifer

Most locations = only intended fro non-potable use (irrigation, fire suppression)

Singapore + California - water given more advanced treatment and used for drinking

Debate over the extent to which all the pathogens and chemicals are removed after treatment

Question 23

Give an example of Recycling Water

Answer 23

Singapore faced with persistent water shortages = has invested in treating and purifying wastewater using dual-membrane and ultraviolet technologies

Makes up 30% of their water supply

Question 24

Explain Greywater

Answer 24

Domestic water - internally used (showers, washing machines) that can be used fro toilet flushing + other non-drinking uses

Potentially saves 30% on bills, but expensive to install (£5,000)

Question 25

Give an example of Greywater

Answer 25

Oxley gate in Milton Keynes - 150 new build houses with greywater systems that can hold enough water for 15 flushes

Question 26

Explain Groundwater management

Answer 26

Maintaining groundwater supplies potentially involving aquifer recharging

At a basic level - involves not taking more water out of an aquifer the is naturally replenished. Aquifers can be recharged anthropologically (deliberately by people) rather than naturally

Question 27

Give an example of groundwater management

Answer 27

Mindaroo Australia

Upside-down weir has been built under a river to allow groundwater to accumulate

Question 28

Give some benefits of recycled water

Answer 28

Sold to citizens at a cheaper rate

Saves potable water for drinking

Contains higher levels of nutrients to help fertilise pants through irrigation

Question 29

Give 3 water conflicts (local, regional, international)

Answer 29

Ica Valley, Peru (local)

California (regional)

Nile Basin (international)

Question 30

Explain water conflict at the Ica Valley, Peru

Answer 30

Industrial production of asparagus is depleting the area’s water resources so fast that smaller farms and families are finding their wells running dry

Exports of asparagus to UK supermarkets = unsustainable

Local water plummeted in 2002 when extraction overtook replenishment

Water levels fall by 8mm per year (fastest rate of aquifer depletion in world)

Water shortage expected to get worse as climate change shrinks the glaciers that feed into the Ica Valley river system

Question 31

Give a positive for the Ica valley’s asparagus growing

Answer 31

Created 10,000 local jobs on the area and brings in $450m a year

Question 32

Give the background water scarcity in California

Answer 32

Demand for water currently exceeds natural supplies

Spatial imbalance - 3/4 population loves in the South, but 3/4 precipitation falls in the north

Persistent high pressure in the Western Pacific Ocean stops storms reaching California between Nov-March, a time when the states get most of their rain

Droughts between 200-2007 and 2011-2015

Question 33

Explain water conflict in California

Answer 33

Water rights are continually disputed. Native Americans have longstanding legal rights. Ownership of the Colorado river has long been disputed between Mexico and USA

Environmentalists are concerned that wetlands have been drained, natural habitat altered and fish stocks depleted

Northern Californians fear ownership of their water by the South, But Southerners are worried about the continuity of there supply

Question 34

Explain the Nile Basin Water conflict

Answer 34

1979 - Egyptian president Sadat stated that “the only matter that could take Egypt into war agin is water” (Nile = matter of national security)

11 states in the Nile Basin, each with a. different plan for the river

The Arab spring has made it unclear wether Egypt is willing or able to enforce its long-held dominance of the region

Great Lakes = notoriously prone t cons;ict. Sudan + South Sudan still clashing over issues from 2005

All countries have paid economic and demographic growth - increased water demand