Water Resources Ocean County Voctional Technical School水资源大洋县职业技术学校.pptVIP

Water Resources An Environmental Science Series The Water Molecule Water: a staple for life Where do we get water? Water Balance Lenthic – standing water (lakes) Lotic – running water (streams) Incoming sources: Precipitation Surface influents Groundwater seepage Groundwater springs Losses: Outlets (drainage) Seepage into groundwater (infiltration) Evaporation Evapotranspiration (macrophytes) Water in the atmosphere Water vapor can be between 0 and 4 % It is considered a Greenhouse Gas It is responsible for condensation to form clouds and precipitation Sources of Water Aquifers both confined and unconfined are important underground reservoirs Surface water sources including rivers, streams, lakes and reservoirs Desalination is also another way to get drinking water Water, Water Everywhere The oceans constitute over 71% of the surface of the earth. Only 3% of the world’s water supply is freshwater (text says 2.6%). Two-thirds of this freshwater supply is tied up in glacial ice. Most of the water is too polluted to drink and must undergo a form of filtration. Water usage! The average toilet uses 5 to 7 gallons of water per flush. A shower can use 25 to 50 gallons of water (5 gallons per minute). The average bath takes about 36 gallons of water. It takes about 1 gallon of water to process a quarter pound of hamburger. Ten gallons of water are needed to refine one gallon of gasoline. Humans require about 2 1/2 quarts of water a day. Methods of Desalination Reverse Osmosis Distillation Evaporation There are some major desalination processing plants. In fact, the Outerbanks, NC and Cape May use this technology. Water without the saltDesalination Irrigation Agriculture accounts for 80 percent of the Nations water use (USDA) Irrigation 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. Water Pollution Types and Treatment Bioavailabilit