Download Chapter 11 Water Water Resources Water Use and Management

Chapter 11 Water
11.1
11.2
11.3
Water Resources
Water Use and Management
Water Pollution
Objectives
 Identify
patterns of global water use.
 Explain
how water is treated so that it can be used
for drinking.
 Identify
how water is used in homes, in industry, and
in agriculture.
 Describe
how dams and water diversion projects are
used to manage freshwater resources.
 Identify
five ways that water can be conserved.
Water Use and Management
 Polluted
or overused water supply affect
everyone living downstream.
A
shortage of clean fresh water is one of the
world’s most pressing environmental problems.
 According
to the World Health Organization,
more than 1 billion people lack access to a
clean, reliable source of fresh water.
Global Water Use
 Three major uses for water:
- residential use
- agricultural use
- industrial use.
Availability of fresh
water, population
sizes, and economic
conditions affect how
people use water.
Residential Water Use
 In the U.S., ½ of it is for home
activities Ex : drinking and
cooking.
 The remainder is for activities
outside the home. Ex: watering
lawns.
Drinking-Water Treatment
 Potable
: suitable for
drinking.
 Treatment
of water:
- removing poisonous
elements. Ex: mercury.
- removing pathogens: substances causing disease.
- includes both physical & chemical treatment.
Industrial Water Use
 19 % is used to:
-manufacture goods.
-dispose of wastes.
-generate power.
 Power-plant cooling systems: pump water from
rivers or lakes, carry it in a cooling tower, then
pumping it back into the source.
 Returned water is warmer than the source.
Agricultural Water Use
 Irrigation: providing plants with
water from sources other than
direct precipitation.
Ex: water filled ditches
Water Management Projects
 Dam
:structure built across rivers to control river’s
flow.
 Reservoir :artificial water -body
formed behind dam.
Used for flood control, drinking
water, irrigation.
 When
the land behind a dam
is flooded, entire ecosystems
can be destroyed.
Water Conservation
 Plant
roots directly deliver small amounts of
water to avoid its loss.(agriculture)
 Recycling
of cooling water and
wastewater.(industry)
 Using
only the water that people need.(home)
 Xeriscaping:
designing a landscape that
requires minimal water use.(home)
Solutions for the Future
 Desalination:
removing salt from ocean water.
- Too expensive since it consumes a lot of
energy.
 Transporting
Water: Ex: ships travelling from the
mainland to the Greek islands with plastic bags
full of fresh water to be pumped onto islands.