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Water's Importance
n/a
34
Environmental Studies
11th Grade
02/04/2010

Additional Environmental Studies Flashcards

 


 

Cards

Term
Water Helps:
Definition
  • Keep us alive
  • Moderates our climates
  • Sculps the land
  • Remove and dilutes wastes and pollutants
Term
Only ____ of the earths water supply is available to us as liquid freshwater
Definition
0.2%
Term
Where does the water go?
Definition
  • Precipitation infiltrates the ground
  • It is stored in soil and rock (aquafer)
  • some water evaporates into the air
  • the rest runs of (surface runoff) into bodies of water
Term
Uses of Water
Definition
  • We use greater than 50% of worlds reliable runoff and could be using 70-90%
  • 70% of the water we take out of rivers, lakes and aquafers is not returned
  • Irrigation uses 70%, Industries 20% and residences use 10%
Term
___% of the worlds population lives in river basins that do not have enough freshwater
Definition
41%
Term
Many parts of the world are experiencing:
Definition
  • Rivers running dry
  • Lakes and Seas shrinking
  • Falling water tables from over-pumped aquafers
Term
Who owns the Water?
Definition
There is a controversey over whether water supplies should be owned and managed by the Government or by private corps.
Term
European based water companies aim to control ___ of US water supplies by buying up water companies and entering into agreements with cities to manage water supplies.
Definition
70%
Term
Cities are outbidding ________ for water supplies from rivers and aquafers
Definition
farmers
Term
Countries are importing _____ as a way to reduce their water use.
Definition
Grain
Term
More crops are being used to produce____.
Definition
Bio-fuels
Term
If we need water, our options are:
Definition
  1. Get more from aquafers and rivers
  2. De-salinate ocean water
  3. Waste less water
Term
Most aquifers are renewable unless,
Definition
Water is removed faster than it is replenished or it becomes contaminated
Term
Advantages of withdrawing groundwater:
Definition
  • useful for drinking and irrigation
  • available year round
  • exists almost everywhere
  • renewable if not overpumped or contaminated
  • No evaporation losses
  • Costs little to extract
Term

Disadvantages to withdrawing groundwater:

 

Definition
  • Aquafer depletion from over pumping
  • sinking of land from overpumping
  • polluted aquafers for decades or longer
  • saltwater intrusion into drinking water
  • as aquafers become depleted, deeper wells cost more
Term
Benefits of large dams and reservoirs:
Definition
  • provides water for year round irrigation and cropland
  • provides water for drinking
  • resevoir for recreational uses
  • production of cheap electricity
  • reduces downstram flooding
Term
Disadvantages to dams:
Definition
  • Flooded land above dam can destroy cropland and forests, displace people
  • Large losses of water through evaporation
  • Cropland and estuaries downstream deprived of nutrient rich silt
  • Dams pose risk of failure
  • Migration and spawning of fish
Term
The Colorodo River
Definition

Too many dams and water withdrawals cause most water to never reach the ocean

  • 14 major dams, resevoirs and canals
  • Water used mostly in desert areas
  • provides electricity for 30 million people (1/10 of US population)
Term
Chinas Three Gorges Dam
Definition

There is a debate as to whether the advantages of the woulds largest dam will outweigh the disadvantages.

  • it will be 2km long (1.24 miles)
  • the electric output will be that of 18 large coal burning plants
  • it will be able to facilitate ship travel to reduce transportation costs
  • dam will displace 1.2 million people
  • dam is built over seismic fault and already has small cracks
Term
Transferring water can make unproductive areas more productive but can cause _________.
Definition

Environmental Damage
Term
Transferring water
Definition
  • promotes investment, jobs and a strong economy
  • encourages unsustainable use of water where water is not naturally supplied.
Term
Removing salt from water is:
Definition
  • costly
  • produces large amounts of saltwater waste
Term
2 methods to desalinate water:
Definition
  • Distillation- heating saltwater until it evaporates
  • Reverse Osmosis- uses high pressure to force saltwater through a membrane filter
Term
Other options to desalinate water:
Definition
  • Seeding clouds to promote rainfall
  • Towing ice bergs
  • Dragging huge bags filled with freshwater
Term
What is wrong with the other ways to desalinate water?
Definition
They are too costly and will produce insignificant amounts of water.
Term
We waste about ___ of the water we use, but we can cut it down to ___.
Definition
2/3, 15%
Term
____ of the water people use throughout the world is lost through evaporations, leaks and other losses.
Definition
65-70%
Term
Water is _____ through government subsidies.
Definition
Underpriced
Term
The lack of government subsidies for improving the efficiancy of water use contributes to:
Definition
water waste
Term
___ of the worlds irrigation water is wasted
Definition
60%
Term
Improved techniques could but world irrigation waste to ___.
Definition
5-20%
Term
Some suggest that we should ____ the price of water while providing ____ rates for the poor.
Definition
increase, low
Term
We must simply _____ our freshwater and use it wisely
Definition
conserve
Term
Effects of too much water:
Definition
  • Heavy rain, snow melt, removal of vegetation and destruction of wetlands cause flooding.
  • Floodplains help probide natural flood and erosion control (we develop these areas)
  • develpment and other human activities have contributed to deaths.
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