AP Environmental Science Water Flashcards

8415029872	Availability of Freshwater	only about 0.024% of the earth's water supply is available to us	0
8415029873	Groundwater	some precipitation infiltrates the ground and is stored in spaces in soil and rock; water in these spaces is one of most important sources of fresh water; moves from high to low elevation	1
8415029874	Zone of Saturation	a certain depth where these spaces are completely filled with water	2
8415029875	Water Table	the top of the zone of saturation	3
8415029876	Aquifers	geological layers deeper down like caverns and porous, layers of sand, gravel, or bedrock through which groundwater flows; contain much more freshwater than lakes and rivers	4
8415029879	Surface Water	the freshwater that flows across the earth's land surface and into rivers, streams, lakes, and reservoirs	5
8415029880	Surface Runoff	precipitation that does not return to the atmosphere by evaporation or infiltrate into the ground	6
8415029881	Watershed	drainage basin; the land fro which surface water drains into a river, lake, wetland, or other body of water	7
8415029889	Withdrawing Groundwater Advantages	useful for drinking and irrigation, available year round and everywhere, renewable, no evaporation losses, cheaper to extract than most surface waters	8
8415029890	Withdrawing Groundwater Disadvantages	depletion from over pumping, sinking of land from over pumping, pollution, saltwater intrusion, reduced water flows into surface waters, increased cost and contamination with more depth	9
8415029894	Advantages to Large Dams	produce cheap electricity, reduce downstream flooding, and provide year-round water for irrigating crop land	10
8415029897	Aral Sea	formerly the fourth largest lake in the world: shallow and saline, now badly polluted; use of its source waters for irrigation led to a loss of over 50% of its area; diverted water was mostly used for irrigation	11
8415029898	Colorado River Basin	Many dams and withdrawals have stopped its flow to the sea; 14 major dams and reservoirs; supplies water mainly to California but is also used for Nevada and other states around	12
8415029899	China's Three Gorges Dam	world's largest dam that helps reduce flooding and provide electricity but displaces many people and will cause flooding in different areas	13
8415029903	Desalination	removing dissolved salts from ocean water or from brackish water in aquifers or lakes for domestic use; Israel uses prominently; two major problems: very costly and takes a lot of energy	14
8415029904	Distillation	heating saltwater until it evaporates, leaves behind salts in solid form, and condenses as freshwarer	15
8415029905	Reverse Osmosis	microfiltration; uses high pressure to force salt water through a membrane filter with pores small enough to remove the salt (pushes freshwater out of salt water)	16
8415029911	Reducing Flood Damage	preserve forests on watersheds, preserve and restore wetlands in floodplains	17
8415029914	Transpiration	the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere	18
8415029919	Ogallala	shallow water table aquifer surrounded by sand, silt, clay and gravel located beneath the Great Plains in the United States	19
8415108767	Disadvantages of Dams	Displaces people and disrupt aquatic systems, and reducing downstream flow	20