Water Resources Oean County Vocational Technical School：水資源大洋縣職業(yè)技術(shù)學(xué)校

1、water resourcesan environmental science series the water moleculehydrogen bondsenergy involved in the phase changes of water water: a staple for lifewww.auf.asn.au/meteorologywhere do we get water?water balancewater in the atmospherenwater vapor can be between 0 and

2、4 %nit is considered a greenhouse gasn it is responsible for condensation to form clouds and precipitationsources of waternaquifers both confined and unconfined are important underground reservoirsnsurface water sources including rivers, streams, lakes and reservoirsndesalination is also another way

3、 to get drinking wateruniversity of michigan u.s. water consumption as per 1995 statistics water, water everywherenthe oceans constitute over 71% of the surface of the earth. nonly 3% of the worlds water supply is freshwater (text says 2.6%).ntwo-thirds of this freshwater supply is tied up in glacia

4、l ice.nmost of the water is too polluted to drink and must undergo a form of filtration. water usage! nthe average toilet uses 5 to 7 gallons of water per flush. na shower can use 25 to 50 gallons of water (5 gallons per minute). nthe average bath takes about 36 gallons of water. nit takes about 1 g

5、allon of water to process a quarter pound of hamburger. nten gallons of water are needed to refine one gallon of gasoline. nhumans require about 2 1/2 quarts of water a day. groundwater concept mapby purdue university, inmethods of desalinationnreverse osmosisndistillationnevaporationthere are some

6、major desalination processing plants. in fact, the outerbanks, nc and cape may use this technology.water without the saltdesalinationreverse osmosis desalination courtesy of usaid (kahn, 1986.) hoover dam information locationinteresting facts the hoover dam is located in the south western united sta

7、tes on the border of nevada and arizona. the dam is 30 miles southeast of las vegas.two lane road allows traffic to travel from nevada to arizona. for security reasons, certain types of vehicles (like heavy trucks) are not allowed to cross the dam . the hoover dam bypass bridge is currently being bu

8、ilt. irrigationnagriculture accounts for 80 percent of the nations water use (usda)nirrigation is critical to agriculture in the united states: nearly half of the value of all crops sold comes from the 16 percent of harvested cropland that is irrigated. cranberry bogs take much water for flooding an

9、d diversion of stream flowsmassachusetts bogs use 41 44 billion of gallons of water per year!water pollutiontypes and treatment we can classify major sources that lead to water pollution: synthetic agricultural chemicals heavy metals hazardous wastes excess organic matter sediment infectious organis

10、ms air pollution thermal pollution soil pollution bioavailability of metalsaccording to the u.s. environmental protection agency metals of major interest that have greatest potential for human exposure and health risk include:other metals that may cause less of a health threat are:these metals can b

11、e dispersed in soil, water and air. metals in soil and sediment, those suspended in the water column, and those found in groundwater are of greatest concern according to usgs publication 2191. biological factors nutrient cyclingnthere are biotic processes including nutrient cycling with phosphorus a

12、nd nitrogennnitrates come from cycling, runoff, and the atmospherenphosphates are put into a system through runoff, cycling or translocation from another source (bird excretion), but not from the atmosphereflorida everglades: a highly altered ecosystem florida bay is 2072 km2 water filtrationndistillation nion exchang