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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