12.3. Water Pollution

Question 1

Drought

Answer 1

a period of below-average precipitation in a given

region, resulting in prolonged shortages in the water supply, whether atmospheric, surface water or ground water

Question 2

Importance of Water

Answer 2

• Human body is 60% water
• Need water to compensate for fluid loss throughout the day
• Fresh-water is such a vital commodity to human civilisation. So increasingly, it is even becoming a source of conflict
• Why? Rivers flow across multiple countries, and when a country dams a river, then water supply would be cut off for the other countries

Question 3

Supply of Water

Answer 3

• The point is that the supply of fresh water is a finite, whilst demand huge and increasing.
• 3% of the world’s water is fresh water and 97% is saline ocean water
• Out of this, 69% is Icecaps and Glaciers, 30% is groundwater, and 0.3% surface water
• Out of the surface water, 87% is found in lakes, 11% swamps, 2% rivers

Question 4

Demand

Answer 4

This is the need for water for a range of uses, also referred to as consumption. (The amount of water consumed reflects the level of demand)

Question 5

Supply

Answer 5

The availability of water by tapping various sources, such as groundwater and surface water (lakes and rivers).

Question 6

Water Balance (+ or -) =

Answer 6

Water Supply – Water Demand

Question 7

Demand for Water

Answer 7

1) Agriculture:
In many parts of the world, precipitation is low and therefore farmers need to irrigate their crops.
2) Industrial Use:
Industry uses huge amounts of water for manufacturing or for cooling (e.g. power stations).
3) Domestic use:
In HICs, large amounts for a huge range of every day uses as well as sanitation and drinking; In LICs, less is used, mostly for drinking.

Question 8

What’s the dominant demand for water?

Answer 8

Agriculture (Very High), then domestic, then industry

Question 9

Factors driving increased demand

Answer 9

• Driving reason for increase rising population.
• Rising standard of living = high domestic use.
• Rise in agricultural productivity to feed people = higher use.
• Industrialisation hand in hand with development. Industry needs water.

Question 10

Evidence for increased demand for water

Answer 10

Between 1950 and 2000:

• Demand from agriculture from c. 1000 cubic KM/year to 3000 (x3)
• Demand from Industry and Domestic from c. 250 to 2,000 (x8)

Question 11

Water Deficit

Answer 11

Demand > Supply

Question 12

Water Surplus

Answer 12

Supply > Demand

Question 13

Water Deficits and Surpluses within a country

Answer 13

different regions within a country can have different climates and levels of population density, thereby creating internal areas of surplus and deficit.

Question 14

We can further split those areas that are suffering from water deficit down into:

Answer 14

Physical water scarcity and Economic water scarcity

Question 15

Physical Water Scarcity

Answer 15

Occurs where water consumption exceeds 60% of the usable supply of water.

Question 16

Economic Water Scarcity

Answer 16

Occurs where a country physically has enough water resources to meet its needs, but a shortage of treatment, storage or transport facilities means that supply cannot meet demand.

Question 17

Reasons for water deficit

Answer 17

• Climate: Precipitation and temperature (evaporation);
• Physical landscape (proximity to rivers and geology);
• Population density, growth and distribution;
• Economic Development (demand and supply infrastructure)
• The importance / prevalence of agriculture.

Question 18

Quality Vs Quantity

Answer 18

• Quality is more important
• It is a trite distinction to make, but it reinforces the point that water for domestic uses, especially drinking water, needs to be clean and free of diseases.
• Natural water is rarely clean enough to drink, therefore
  treatment works and infrastructure to deliver clean water to people is required.

Question 19

Providing Clean Water

Answer 19

• It is generally considered to be a government’s role
  to provide this infrastructure.
• The infrastructure is relatively affordable.
• However, it can be difficult to provide, maintain or this
  infrastructure in rural environments or remote areas, especially in LIC and MIC countries.

Question 20

Factors that impact water quality

Answer 20

Water, like air, is fluid and therefore polluted or poor quality water can easily spread over long distances

1) Agriculture
2) Industry
3) Energy production:
4) Domestic waste

Question 21

Factors that impact water quality (Agriculture)

Answer 21

• Through increasing use of chemical fertilisers as well as animal waste. Leaching and surface run-off washed into water courses or groundwater, degrading water quality or causing eutrophication.
• Pesticides, Herbicides

Question 22

Factors that impact water quality (Industry)

Answer 22

• Liquid wastes or by-products are often dumped into water courses rather than expensive processing, especially in LICs

Question 23

Factors that impact water quality (Energy production)

Answer 23

• Oil spills, air pollution leading to acid rain, hot water from thermal power stations being dumped, containing little oxygen, low-level radioactive waste from nuclear power.

Question 24

Factors that impact water quality (Domestic waste)

Answer 24

• If there is inadequate sanitation infrastructure, sewage or domestic waste water can easily pollute watercourses or groundwater in LICs;
• Domestic rubbish is often dumped in HICs, or poor waste collection services in LICs / MICs lead to a higher chance of waste being washed into water courses.

Question 25

Niger Community Wells - Needs

Answer 25

• Lowest HDI with large rural population and very large country.
• Reliance on groundwater, but arid region and no sanitation so groundwater easily contaminated.
• Existing wells widely scattered; time and labour consuming

Physical water scarcity
- Arid country, with the Sahara desert, so it has low levels of water to use
Economic water scarcity
- The country is so remote that the government can’t implement (lack of money too) fresh water infrastructure
- Reliance on groundwater - domestic pollution through sanitation and Agricultural waste - animal waste

Question 26

Niger Community Wells - Advantages

Answer 26

• Reliable, local source of freshwater with health benefits.
• Frees time for education and economic activity.
• Drilling and pump manufacture provides employment.

Question 27

Niger Community Wells - Disadvantages

Answer 27

• Potentially cost and over-extraction of groundwater.

Question 28

Philippines Water Shops - Needs

Answer 28

• Rapidly growing population and urbanisation in an LIC, with attendant issues of providing modern infrastructure.
• Public distrust of previously contaminated water supply.
• This overcomes the supply of issue where demand is rapidly growing and it is difficult to provide infrastructure
• Overcomes the issue of domestic and industrial water quality in urban areas

Question 29

Philippines Water Shops - Advantages

Answer 29

• Fraction of the cost of commercially bottled water.
• Reliable supply, often in conjunction with the government.
• As the shops are often private, they are not solely funded by govt.

Question 30

Philippines Water Shops - Disadvantages

Answer 30

• Groundwater over-extraction and contamination from unauthorised sellers;
• Does not address the long-term water supply and quality issues.