Transcript Freshwater Resources

Freshwater Resources
Chapter 12
Lesson 1 Main Ideas
• Fresh water supports life
• Most human activities require water
• Dams and other structures alter rivers
Why is water so
important to humans?
• Human body is mostly water (blood, skin, etc)
• No one can live without water more than a few
days
• People use water to grow food
• Water is used for transportation of people and
goods
U S cities near water
• Portland, Oregon
• Omaha, Nebraska
• Cleveland, Ohio
• Pittsburgh, Pennsylvania
• St Louis, Missouri
• New Orleans, Louisiana
• San Francisco, California
Activities require water
• Shower, brush teeth, clean dishes and
clothes, cook, fill pools, grow crops, making
paper, generates electricity, mining, etc...
• Farming, Industry, Transportation, Recreation,
Fisheries and Aquaculture, Energy
Farming
• 40% of the water that is used goes to growing
crops and raising livestock (eating)
• Farmers near dry areas must irrigate waterdraw water from aquifers, rivers, or lakes
• Over half US farms use flood irrigation instead
of spray irrigation
Industry
• Factories use water to make cars, notebooks,
jeans, shoes, skateboards, and televisionsalmost all products
• Water used in factories can be used again or
cleaned and returned to lakes or rivers
Transportation &
Recreation
• Trading goods or visiting areas
• Rafting, canoeing, kayaking, camping,
picnicking, swimming, fishing, etc...
• Canals sometimes are built as a bypass or to
connect waterways
Aquaculture
• Fresh water is full of life! Tiny one celled
organisms, shrimp, worms, fish, etc…
• Food is provided to humans and to other
animals like frogs, insects, birds, etc…
• Fish farming is very popular for catfish, trout,
salmon-only problem is excess nutrients
flowing into rivers
• Fish hatcheries help threatened species
survive
Energy
• Force of water powers machines
• Water generates electricity
• Water is used to cool nuclear power plants
Altering Rivers
• Landscape changes when dams are built
• Ecosystems are changed when dams are built
• Canals are used to connect rivers
• Dams can cause flooding
Lesson 2 Main Ideas
• Treatment makes water safe for drinking
• Waste water is treated and released
• Water pollution comes from many sources
• Water pollution can be prevented
Drinking Water
• From wells or reservoirs
• Stored in tanks
• Flows through pipes to buildings
• May contain impurities or organisms that
cause disease
Water Quality
• Environment Protection Agency (EPA) sets
standards for safe clean drinking water
• Towns also have laws for safe water-Prattville
Water Works constantly tests our water to
make sure it is clean and safe
• If water is contaminated, it must be treated
before used
Water Contaminates
• Chlorine and fluoride
• Copper, Lead and other metals
• Cyanide and Mercury
• Etc…
Treatment
• Water is piped into plant from lake or river
• Disinfecting can clumping occurs to collect dirt
and bacteria
• Clarifying is next to make it clear
• Tiny particles are filtered by flowing through
coal, sand and gravel
• Chlorine is added to kill bacteria then it is
stored
Waste Water
• Waste water is treated with sewage or septic
tanks
• Each city/town has a sewage system to carry
waste water from building to the treatment
plant
Sewage
• To begin with it is strained and sits to allow
sludge to sink to bottom then removed
• Chlorine is added to kill about half bacteria
• Oxygen is pumped in and grease skimmed off
the top
• Chemicals clean water and pump it back out
Septic Systems
• Used by a home or business (not town)
• Sludge settles to bottom of tank and is
consumed by bacteria. Some sludge has to be
removed from tank every few years
• Water exits tank and spreads and sinks into
the ground
Water pollution
• Humans make fresh water contaminated too.
• Homes-household chemicals and pesticides
• Cities-Toxic chemicals, Motor oil
• Sewage-dumping raw waste
• Farms-animal waste and fertilizers/pesticides
• Shipping-oil spills
Prevention
• When water is polluted, there is less fresh
water to use. Polluted water can endanger
our health.
• Pass laws to limit dumping, recycle and reuse,
stop leaks, decrease pavement, inspect
vehicles
• Fence animals on farms, organic foods, proper
disposal of all hazardous waste
Lesson 3 Main Ideas
• Water shortages are a global problem.
• Overuse can cause water shortages.
• Fresh water can be conserved.
• People can balance water needs and uses.
Global water
• Many nations have severe fresh water
shortages.
• Water supply is dwindling all over the world
due to population growth (feeding)
• Aquifers are being emptied faster than they
are refilling
Overuse
• Agriculture uses most of the water around the
world but only half the water used on plants
reaches the roots-other evaporates or runs off
• Seven states use water from the Colorado
river. About half a billion people in 31
countries currently face water shortages. 3
states and Mexico share Rio Grande water
• Aquifers are emptying and river levels are
decreasing-both take years to refill
Conserve
• It’s not hopeless! Three ways to conserve:
• 1) repair leaks 2) reuse water 3) recycle water
• Farmers conserve using drip irrigation,
factories reuse water, modern plumbing in
homes, shorter showers, turn off water, etc
Balance
• People need to balance needs and uses.
• Debates in our town, state, country on what is
a need – pools, lawns, hydration, grow food,
make products, etc…
Some Solutions
• World Food Program -International
organization that provides food to countries
experiencing drought. United Nations has food
aid.
• States and countries make agreements about
shared rivers and lakes and pollution levels
• Possible solution for future: pipeline for fresh
water from Alaska to travel to California
New Solution
• Desalination-process of removing salt from the
ocean
• Dry regions like Israel. Coastal areas like
California and Florida.
• This process is difficult and expensive
• Icebergs-obtain fresh water from iceberg but
the thawing and transportation is costly
U.S. Water Uses
• Americans use an average of 168 liters per
person each day!
• 29% toilet flushes, 21% washing clothes, 21%
showers, 12% faucet drain, 9% bath tub, 3%
washing dishes, 5% water leaks
Conclusion
• Fresh water is a valuable natural resource that
needs to be protected and not taken for
granted!