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CHONG BOON SECONDARY SCHOOLLower Sec Geography

Secondary Two

Unit 13: Understanding The Water Supply

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*Thinking Questions

1. Is water really a scarce resource even when it covers 70% of the Earth’s surface?

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*Thinking Questions

70% Water

30 % Land

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L.O.L

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*Unit Objectives

1.Explain the reasons for water constraint.

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*Background on Earth’s Water Supply

•Seas & Oceans (Salt Water) 97% of Earth’s Water

•Fresh Water 3%

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Background on Earth’s Water SupplyOf the 3% of fresh water,• 75.0% stored as ice sheets and glaciers • 21% ground water and soil moisture • 4% rivers and lakes (0.1% of ALL the water on

Earth)

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Background on Earth’s Water Supply

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*What is the problem?

A. Water is scarce

B. Rising demand for water

Recall: Is it similar to the case of land supply? Same same but different?

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*Reason for Water Scarcity (Why is there a problem?)

A1. Only 0.1% of Earth’s water supply is accessible for drinkable use

A2. Uneven distribution of precipitation (rain, snow, etc.)

- Low annual precipitation in places like North Africa, Middle East or desert areas

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A3. Climate Change - Global warming led to an increase in number

of prolonged droughts

A4. Deforestation - Cause floods as rain water flows into rivers faster and brings sediment - Flooding leads to contamination of clean water

- Less water infiltrates into the soil/ground

*Reason for Water Scarcity (Why is there a problem?)

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*Reason for Water Scarcity (Why is there a problem?)

A5. Poor farming practices - monoculture (single crop is planted repeated makes land infertile)

- over-cropping (farming on already low fertile land)

- over-grazing of animals

- overuse of chemical fertilisers

Note: 2nd & 3rd point leads to soil erosion due to similar effect as deforestation on a micro-scale

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*Reason for Rising Demand of Water (Why is there a problem?)

B1. Increase in population - greater demand for bathing, washing, drinking etc.

B2. Increase in agricultural activities - more people means increase in consumption of food - more water is needed for irrigation

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B3. Increase in industrial and commercial activities - industries require large amounts of water for their processes (wafer/micro-chip production, etc)

*Reason for Rising Demand of Water (Why is there a problem?)

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Where are some of the places with this problem?

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Where are some of the places with this problem?

1.Kuwait (Middle East)?

2.Africa?

3.Singapore?

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Where does Singapore get our water from? •NeWater

• Imported Water (Malaysia?)

•Water Catchment Areas (Reservoirs)

•Desalination

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How much is Singapore’s water demand? •1 billion Litres of water DAILY

(575 times Olympic size swimming pool)

•150L per person per day on average

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Who are affected?

You, me & future generation.

Plants & animals? To a lesser extent?

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Mind-mapping timeIncrease in industrial and commercial activities

Rising demand for water 0.1% of water is accessible and usable

Uneven distribution of precipitation

Climate Change Increase in agricultural activities

Poor farming practices Increase in population Deforestation

Earth – 70% Water 30% Land