Water Resources

1
Water Resources
G. Tyler Millers Living in the Environment 14th
Edition Chapter 15
2
Key Concepts

• The physical properties of water

• Availability of fresh water

• Methods of increasing freshwater supplies

• Using water more efficiently

• Problems associated with flooding

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Waters Unique Properties

• Hydrogen bonding

• Liquid over wide temperature range

• Changes temperature slowly

• High heat of evaporation

• Great dissolving power

• Filters out ultraviolet radiation

• Adhesion and cohesion

• Expands when it freezes

4
Supply of Water Resources
Fig. 15-2 p. 307
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Surface Water

• Surface runoff

• Watersheds

• Reliable runoff

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Ground Water
Fig. 15-3 p. 308
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Use of Water Resources

• Humans use about 54 of reliable runoff

• Agriculture

• Industry

• Domestic

• Power plants

Fig. 15-4 p. 309
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Too Little Water

• Dry climate

• Drought

• Desiccation

• Water stress

Fig. 15-6 p. 310
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Using Dams and Reservoirs to Supply More Water
The Trade-offs
Fig. 15-9 p. 313
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Transferring Water from One Place to Another

• Watershed transfer

• California Water Project

• Central Arizona Project

• James Bay

Fig. 15-13 p. 317
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Tapping Groundwater

• Year-round use

• No evaporation losses

• Often less expensive

• Potential Problems!

Refer to Fig. 15-15 p. 319
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Problems with Using Groundwater

• Water table lowering (See Fig. 15-15 p. 319)

• Depletion (See Fig. 15-16 p. 320)

• Subsidence (See Fig. 15-16 p. 320)

• Saltwater intrusion (See Fig. 15-17 p. 320)

• Chemical contamination

• Reduced stream flows

13
Converting Salt Water to Fresh Water and Making
it Rain

• Distillation desalination

• Reverse osmosis desalination

• Desalination is very expensive

• Cloud seeding

14
Using Water More Efficiently

• Reduce losses due to leakage

• Reform water laws

• Improve irrigation efficiency (Fig. 15-20 p. 324)

• Improving manufacturing processes

• Water efficient landscaping (xeriscaping)

• Water efficient appliances

15
Too Much Water Floods

• Natural phenomena

• Aggravated by human activities

Reservoir
Dam
Levee
Flood wall
Floodplain
Fig. 15-24 p. 327
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Solutions Achieving a More Sustainable Water
Future

• Efficient irrigation

• Water-saving technologies

• Improving water management

See Fig. 15-26 p. 329