Transcript Water

Water
Ch.apter 11
11-1 Water Resources
Objectives
1. Describe the distribution of Earth’s water
resources.
2. Explain why fresh water is one of Earth’s
limited resources.
3. Describe the distribution of Earth’s surface
water.
4. Describe the relationship between
groundwater and surface water in a
watershed.
 Water
Cycle
Water is a renewable resource
but freshwater is limited
Evaporation – condensation precipitation
 Global
Water Distribution
Saltwater
97%
Freshwater
3%
77% Ice caps/glaciers
22% groundwater
1 % other fresh (rivers,
lakes, streams)
 Surface
Water
Fresh water on Earth’s land
surface
Cities build near rivers and
major bodies of water
Supply drinking water,
irrigation water, power,
transpiration, etc.
Rivers
Largest:
Amazon River
Watersheds: area of
land drained by a river
 Groundwater
Water
beneath the Earth’s
Surface
Water table
Water reaches a level
where rocks and soil or
saturated
Aquifers
Underground
formations
that contain water
Consists
of material such of
rock, sand, and gravel
Spore spaces in the rocks
act like a sponge to hold
water
Example:
Ogallala Aquifer
in the Plains of US
Holds 4 quadrillion liters
of water (enough to cover
US with .5 meters of
water!)
Rocks
are very porous
Porosity-amount of space
between particles
Rocks can be permeable or
impermeable
Limestone, sandstone, and
gravel are permeable
Granite and clay are
impermeable
Use
of wells
Used for irrigation,
drinking water, etc.
Pumping of water creates
a depression or cone in
the aquifer
11-2 Water Use and
Management
Objectives
1. Identify patterns of global water use.
2. Explain how water is treated so that it can be used
for drinking.
3. Identify how water is used in homes, in industry,
and in agriculture.
4. Describe how dams and water diversion projects
are used to manage freshwater resources.
5. Identify five ways that water can be conserved.
 Shortage
of fresh water is a huge
environmental problem
 WHO states that 1 billion
people world wide lack access to
clean water
 Global
Use
Residential
Agriculture
Industrial
Most
fresh water is used for
irrigation
Residential
In
the US the ave. person
uses 300 L (80 G) / day
India only uses 41 L
Daily
usage/person
Lawns
Toilet
Baths
Brush Teeth
Cleaning
Cooking
Other
95L
90L
70L
10L
20L
10L
5L
 Water
Treatment
Water is treated to make it
potable
Removes mercury, arsenic,
and lead (poisonous)
pathogens
Treatment
process
1st filtration removes “big
chunks”
Coagulation – addition of
alum that bacteria clump to
then sink to the bottom)
nd
2 Filtration uses sand,
gravel, and coal filters to
remove other impurities
Chlorination
prevents
bacteria contamination
Aeration forces air to remove
gases and improve smells
Additional treatment for
taste
 Industrial
Water use
19% of water used in the world
Used in manufacturing,
disposal, power generation,
cooling
 Agriculture
300
L used for 1 Ear of Corn to
grow
Water used for irrigation
67% of world’s water usage
 Water
management practice
Roman Aqueducts
French and Spanish canals
 Water
Diversion
Diverts water from major
rivers
Colorado River
 Dams
and Reservoirs
Dams are structures that are
used to control river flow
Reservoirs hold water behind
dams
Used to create power,
irrigation, drinking water
Problems:
fertile sediment is
trapped, natural flow of river
stopped, flooded land, failed
dams
 Water
Conservation
Agriculture is beginning to
use different types of irrigation
(drip)
Industry is recycling water
used
Home
How can you conserve water
usage at home????
 Future
Desalination
– very costly;
heats salt water and collects
water that evaporates
Transportation of fresh water
–
Icebergs, Alaska
11-3 Water Pollution
Objectives
1. Compare point-source pollution and nonpointsource pollution.
2. Classify water pollutants by five types.
3. Explain why groundwater pollution is difficult to
clean.
4. Describe the major sources of ocean pollution, and
explain the effects of pollution on ecosystems.
5. Describe six major laws designed to improve water
quality in the United States.
 Water
Pollution
Introduction of chemical,
physical, or biological agents
into water that degrades
quality
Main causes: industrialization
and population growth
 Sources
Point-Source
Pollution
Discharge from a single
source
Septic
tanks, leaky storage
lagoons, unlined landfills,
leaky underground
chemical storage tanks,
abandoned mine water,
discharge from treatment
plants
Non
point pollution
Many different sources
Road chemicals (salt, etc),
streets (gas, antifreeze),
pesticides, herbicides,
refrigerator and air
conditioner coolants,
livestock feed yards, acid
rain, construction sites,
oil/ gas from boats
 Pollutant
Types
Pathogens
Organics
Inorganics
Heavy metals
Physical agents
 Waste
Water
Water is treated enough to
release it back into lakes and
streams
Sludge is usually burned
 Artificial
Eutrophication
Caused by humans
Acceleration of natural process
Caused by extra nutrients
being added to bodies of water
 Thermal
Pollution
Temperature of body of water
increases
Reduces levels of dissolved
Oxygen so fish will die
Dissolved oxygen is amt. of
O in the water
Produced by
photosynthesis
 Groundwater
Pollution
Percolates from surface
Can come from underground
storage tanks
Hard to clean up because
recharge is slow
 Ocean
pollution
Oils spills
Cruise ships
7 billion kg of garbage is
dumped every year!
85% of ocean pollutions comes
from activities on land (oils,
pesticides, fertilizers)