Theme 3 - 3.6 - Water

Question 1

Define water supply.

Answer 1

The provision of water by public utilities, commercial organisations or by community endeavours.

Question 2

Define dam.

Answer 2

A barrier that holds back water.

Question 3

Define reservoir.

Answer 3

An artificial lake primarily used for storing water.

Question 4

Define wells and boreholes.

Answer 4

A means of tapping into various types of aquifers, gaining access to groundwater.

Question 5

Define potable water.

Answer 5

Water that is free from impurities, pollution and bacteria, and thus is safe to drink.

Question 6

Define water stress.

Answer 6

When water supply is below 1700 cubic metres per person per year.

Question 7

What are some different methods of water supply?

Answer 7

• Reservoirs/Dams
• Wells
• Boreholes
• Desalination
• Aquifers (+ wells)
• Rivers/Lakes

Question 8

What are some advantages and disadvantages of reservoirs/dams for water supply?

Answer 8

ADV.
• Stores water during prolonged periods of rain
• Water can be used to generate HEP
DIS.
• Expensive to build
• Building dams can flood areas
• Eroded material is trapped by the dam, reducing fertility of land downstream
• Water is lost in hot countries due to evaporation

Question 9

What are some advantages and disadvantages of rivers/lakes for water supply?

Answer 9

ADV.
• No construction needed
• Can be used for other activities 
DIS.
• Risk of flooding
• Rivers don't trap water during heavy rainfall
• Are easily polluted

Question 10

What are some advantages and disadvantages of desalination for water supply?

Answer 10

ADV.
• It preserves fresh water supplies
• Not dependent on changing factors (e.g. weather)
• Proven method which is scientifically backed -> Reliable
DIS.
• Plants are expensive to build
• Expensive process
• Requires lots of energy

Question 11

What are some advantages and disadvantages of wells and bore holes for water supply?

Answer 11

ADV.
• Self-sufficiency 
• Cheap
DIS.
• Easily contaminated
• Danger of falling in

Question 12

What are the main sources of water around the world?

Answer 12

Lakes and rivers

Question 13

Describe the global water crisis.

Answer 13

• Lack of water is a constant threat in about 80 countries, with 40% of the world’s population.
• Demand for water is doubling every 20 years
• In poor countries, water supplies are often polluted

Question 14

What are on-channel and off-channel reservoirs?

Answer 14

On-channel: Dam built across an existing river

Off-channel: Natural and human dug depressions which hold water

Question 15

What is an aquifer?

Answer 15

An underground layer of water-bearing permeable rock, from which water can be extracted.

Question 16

How is what extracted from an aquifer?

Answer 16

Wells are used.

Question 17

In the 20th Century, what allowed water consumption to rise?

Answer 17

The building of many new dams.

Question 18

Why are not many new dams being built as what can be done instead?

Answer 18

The best locations are already taken or are strongly protected. Instead, existing dams can sometimes be made higher to increase the reservoir capacity.

Question 19

How much of the world water supply do aquifers account for?

Answer 19

Drinking water - 50%
Industry - 40%
Irrigation water - 30%

Question 20

What is water from a well/aquifer known as?

Answer 20

Groundwater

Question 21

How much of the UK water supply comes from groundwater (aquifers)?

Answer 21

35%

Question 22

Where is groundwater (aquifers) most important?

Answer 22

Arid and semi-arid areas.

Question 23

Where is desalination common and why is this possible?

Answer 23

• In the Middle East, where other forms of water supply are scarce.
• It is possible because waste gases from oil wells are used. Otherwise, it would be very expensive.

Question 24

Why is desalination not very common?

Answer 24

It is expensive.

Question 25

How does total water use change with development?

Answer 25

It increases.

Question 26

Give some reasons why total water use is higher in MEDCs than LEDCs.

Answer 26

* More electricity has to be generated * More industrial activity * People can afford to use more water

Question 27

Describe water use by type in LEDCs.

Answer 27

* Most used in agriculture | * Little used in industry and domestic use

Question 28

Describe water use by type in MEDCs.

Answer 28

* Most used industry * Less used in agriculture (but still can be a lot) * More used for domestic use

Question 29

Is water use in agriculture in MEDCs always low?

Answer 29

No, not always. There are exceptions such as the US, which use a large percentage in agriculture.

Question 30

Does water supply depend only on precipitation amounts?

Answer 30

No, water supply is what matters. It could rain a lot, but there may be no way of collecting and storing this water, for example.

Question 31

Describe the uneven precipitation in the world.

Answer 31

* Over 60% of the world population live in areas receiving only 25% of the world annual precipitation. * Arid regions cover 40% of the world's land area, but receive only 2% of global precipitation.

Question 32

What are the two types of water scarcity?

Answer 32

* Physical water scarcity | * Economic water scarcity

Question 33

What is physical water scarcity?

Answer 33

When physical access to water is limited

Question 34

What is economic water scarcity?

Answer 34

When a population does not have the enough money to make use of a source of water.

Question 35

Which regions usually suffer due to physical water scarcity?

Answer 35

Arid and semi-arid regions in the world.

Question 36

Which regions usually suffer due to economic water scarcity?

Answer 36

Much of sub-Saharan Africa.

Question 37

What are some reasons for water scarcity?

Answer 37

``` INCREASING DEMAND • Increasing population • Increasing agricultural, industrial and domestic use • Increased energy production FALLING SUPPLY • Climate change • Groundwater depletion • Pollution (due to sewage, etc.) • Deforestation -> Trees prevent excessive evaporation • Political issues + War • Mismanagement • Uneven precipitation distribution ```

Question 38

What are some impacts of lack of access to clean water on local people?

Answer 38

* Agricultural loss * Famine * Animals dying * Loss of income * Disease/Illness -> Death * Children have to walk far to get water -> Can't get education * Sanitation issues (e.g. can't wash)

Question 39

What are the impacts of lack of access to clean water on economic development?

Answer 39

* Less water for agriculture and industry -> LEDCs reliant on agriculture * Worker efficiency reduced -> Diseases and tiredness * Tourism is reduced (people don't want to visit that place) * Higher cost of water mean people have less money to spend on other things which fuel the economy * Production of water-intensive goods (e.g. cars) is reduced * Limits production of biofuels

Question 40

How can a lack of water lead to competition and conflict?

Answer 40

* In Yemen, 70-80% of rural conflicts are due to water-related disputes * In 2012, in Kenya, over 100 people were killed in clashes between farmers and cattle grazers * During drought, large companies fight over water

Question 41

What are the two ways in which water conflicts may happen?

Answer 41

1. Demand for water exceeds supply | 2. Control over access and allocation of water may be disputed

Question 42

How can water supplies be managed?

Answer 42

* More sustainable use (e.g. taking a shower instead of a bath) * Increasing cost of water to encourage lower use * Finding new ways to exploit alternative sources instead of those being depleted * Piping water from areas with a surplus to areas with a lack * Making sure that water supply is of good quality * Making sure that broken pipes are mended * Developing more efficient irrigation systems * Educating people about water use * Recycle water

Question 43

What is sustainable water use?

Answer 43

Using water supplies whilst maintaining levels for use in the future.

Question 44

Who's responsibility is sustainable water use?

Answer 44

Both a national and individual responsibility.