Transcript Water Use and Management (Section 11.2)

Bellringer
1.
Write the expression shown below,
and explain what it means:
“We all live downstream.”
2.
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".
3.
4.
Water Use and
Management
Section 11.2
1.
4.
Objectives:
Identify sources of local drinking water.
2.
Explain how water is treated.
3.
Identify principal uses of water.
Describe water conservation methods.
Global Water Use

3 major uses for water:
1.
2.
3.


Residential use
Agricultural use
Industrial use
Which way(s) do you use water?
Would different countries use water
differently?
Global Water Use (cont.)
(Fig.5, p.277)
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

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)
1.
2.
3.
4.
5.
6.
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
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?

3. Agricultural Water Use


67% of water
used worldwide!
Irrigation:
providing plants
with water
1.
2.
Shallow ditches
Overhead
sprinklers –
most lost to
evaporation
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
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
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)
Water
Conservation
(cont.)




In industry recycling cooling
water and
wastewater
At home
Can one person
make a difference?
Table 2, p.282
Other Solutions
1.
2.
Desalination: the process of removing
salt from salt water
Transporting fresh water
1.
2.
3.
4.
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?)