Bellringer

1
Bellringer

• Write the expression shown below, and explain
  what it means
• We all live downstream.
• List all the ways you use water in a typical day.
• List ways you could conserve water without
  severely altering your lifestyle.
• Name some reasons people would experience a water
  "shortage".

2
Water Use and ManagementSection 11.2

• Objectives
• Identify sources of local drinking water.
• Explain how water is treated.
• Identify principal uses of water.
• Describe water conservation methods.

3
Global Water Use

• 3 major uses for water
• Residential use
• Agricultural use
• Industrial use
• Which way(s) do you use water?
• Would different countries use water differently?

4
Global Water Use (cont.)(Fig.5, p.277)
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1. Residential Water Use

• In the U.S., each person uses about 300 L (80
  gal) a day in India, 41 L a day.
• How do you think we use it?
• Table 1, p.277

6
1. Residential Water Use (cont.)

• Water treatment
• Potable safe to drink
• Removes poisons and pathogens organisms that
  cause disease or illness
• Drinking-water treatment steps (p.276)
• Filtration removes trash and large organisms
• Coagulation Alum forms sticky globs that stick
  to bacteria
• 2nd filtration
• Chlorination prevents growth of bacteria
• Aeration Air forced in to remove unwanted gases
• Additives fluoride, water softeners

7
2. Industrial Water Use

• 19 of water used worldwide
• Most is used to cool power plants.
• Pull water from surface sources, run it through
  pipes in a cooling tower, and pump it back to its
  source.
• How would this cool the power plant?
• How would this affect the temperature of the
  water in the pipes?
• How would this affect the surface water source?

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3. Agricultural Water Use

• 67 of water used worldwide!
• Irrigation providing plants with water
• Shallow ditches
• Overhead sprinklers most lost to evaporation

9
Water Management Projects

• Water diversion projects diverting water to
  areas that need it (EX canals)
• Dams and Reservoirs
• Dams structures built across rivers to control
  water flow
• Reservoirs artificial lakes formed behind dams

10
Water Management Projects, continued..

• What would be some advantages to building dams
  and reservoirs?
• Pros Water can be used for drinking water,
  irrigation, electrical energy, flood control,
  recreation
• What would be some disadvantages to building dams
  and reservoirs?
• Cons floods upstream, lack of sediments
  downstream (less fertile land), dam failure

11
Water Conservation

• Why conserve water?
• In agriculture
• Most loss is due to evaporation, runoff, and
  seepage
• Drip irrigation systems deliver small amounts of
  water directly to the roots through perforated
  tubes (Think soaker hose)

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Water Conservation (cont.)

• In industry - recycling cooling water and
  wastewater
• At home
• Can one person make a difference?
• Table 2, p.282

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Other Solutions

• Desalination the process of removing salt from
  salt water
• Transporting fresh water
• In Greece, ships tow large plastic bags full of
  fresh water to the islands.
• U.S. is considering towing fresh water from
  Alaska to California.
• Why would AK have extra and CA not have enough?
• Towing icebergs to other locations has long been
  considered, but not figured out. (What problems
  would there be?)