water quantity and quality. hydrolocic cycle hydrologic cycle with humans
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“Usable” Water Salt water (97%) Fresh water (3%)
Ice (2%) Groundwater (0.97%) “Surface” water (0.03%)
Consider which of these is usable for drinking water.
Water uses - Agriculture Huge amounts of withdrawal and
consumption (70% worldwide) Various irrigation systems, but consider
efficiency Dams, canals, pumps
Industrial uses About 20% worldwide withdrawal Power production is primary usage here;
most is non-consumptive Degradation is big problem
Domestic water use 10% of withdrawals worldwide
Toilets, teeth brushing and hand washing, drinking/cooking, laundry and dishes, bathing
US water “policies” Riparian rights: can use water as long as
doesn’t interfere with others (eastern US)
Appropriation rights: first in time, first in rights….buying and selling of water rights…beneficial use….western US
Watershed management System approach
surface water, land use, groundwater
Area of land that supplies water to a river
Examples: Mississippi, Colorado, Catawba
Watershed of the Catawba River Upper Catawba Lower Catawba
Dams Benefits: power, recreation, flood control,
water supplies for some cities and towns Costs: displacement of people, sediment
disruption, habitat alterations, disruption of flooding needed for healthy soils
Lakes of the CatawbaNorth Carolina James Rhodhiss Hickory Lookout Shoals Norman Mountain Island Half of Wylie
South Carolina Half of Wylie Fishing Creek Wateree
Water quality relative to population along Catawba
C a t a w b a L a k e s i n 1 9 9 0
02 04 06 08 0
1 0 0
0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0
P o p u l a t i o n ( i n t h o u s a n d s )
Water Q
uality Inde
x
From Duke Power data
Water pollution Water pollution: departure from purity
Sources: point vs. non-point sources
Problems caused and possible solutions
Examples of pollution (1) Toxic chemicals
Pesticides, petroleum, synthetic chemicals
Pathogens and waterborne diseases Sewage is a primary source
Examples of pollution (2) Nutrients: primarily P and N
Algal blooms
Oxygen-demanding wastes Effects on DO and BOD
Water treatment Drinking water
What about bottled water? Wastewater treatment
Primary treatment Secondary treatment
Role of buffers and wetlands
Some solutions Source reduction Land management:
Soil conservation helps water quality Addition or preservation of wetlands
Proper sewage disposal Primary vs. secondary treatment Living machines or natural systems
Preventing overfishing Consumer choices Marine reserves Fishing methods
Seafood Watch:(www.montereybayaquarium.org/cr/seafoodwatch.asp)