Fresh Water
Fresh Water
• Only 3% of the water on earth is fresh
water:
– Hydrologic cycle
– Shortages do occur
– Groundwater supplies can be exhausted
• Pollution of fresh water a growing concern
– Major transporter of diseases, cholera,
intestinal and other water borne diseases
Use of Fresh Water
• We require about 80 liters a day
• per capita consumption varies… have and
have nots
Problems
• As global warming accelerates,
evaporation from fresh water and ground
water surfaces will increase
• Areas will increase with water deficits
– Marginal areas ; desertification
– Irrigation needs
Fresh Water Sources
• Lakes ;stored water
such as reservoirs
• Rivers: dams
• groundwater
• Advantages of these
sources: renewal
• Disadvantages of
these sources:
pollution
Water Transfer, Storage and Conservation
• Interbasin transfer: canals, dams
• Groundwater ; Ogallala aquifer, US
• Problems:
– Reduce volume in river perhaps leads to
increase temperatures, reduce wetland
habitat impact on birds and fish
– Examples: James Bay, Bennett Dam, Hoover
Dam, Aswan Damm
Solving the Problem
• Conservation:
– Domestic
– Agriculture – drip irrigation, mulching, crop
planting to reduce run –off and evaporation
Fresh Water Pollution
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Septic tanks
Storm drains
Landfills
Mine-tailings (acid wash drainage) local
ex. Britannia Mines
http://geopanorama.rncan.gc.ca/vancouver/sea_e.php?p=1
Great Lakes
• Dug out thousands of years ago by glacial
action
• Resemble oceans, contain a large
percentage of Canada’s fresh water
– Decline in water levels
– Increase evaporation rates due to climate
change (parts of lakes don’t freeze)
– Industrial, urban, agricultural needs are
greater than before (are greater than the
watershed’s cycle of replenishment)
Waterways in Peril
• Pollution
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Enclosed water system (not flush readily)
Eutrophication
Accumulation of chemicals in the food chain
Industrial, urban, agriculture pollutants
Clean up difficult:
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International: need cooperation
Lake bottom accumulation a problem
Treating sewage
Shipping m; foreign species
Concentration of industrial activity
Nimby syndrome
Solutions
• Great Lakes
– Line pits
– Dispose of waste correctly
– Upgrade sewage plants
– Industry must comply (reduce acid rain)
– Reduce agriculture pesticides (find safe
alternatives)
– Use incinerators to burn waste
Solutions for Fresh Water
• Recycle programs: reduce garbage bound
for landfill sites
• Recycle engine oil, paint
• No use of chemicals
• Compost bin
• Smart shopper
• Share knowledge
• Use biodegradable soap