Earth and Environmental Science Unit 4 Test Questions & Answers

Three types of wells - ANSWERS- Dug - Driven - Drilled Dug wells - ANSWERSDigging with a pick and shovel Driven wells - ANSWERSDriving a small diameter pipe into the soft earth Drilled wells - ANSWERSRotary drill bits mounted on a truck, chew away at the Earth, percussion bits that smash the rock Negative effects of groundwater depletion - ANSWERS- Lowering of water table - Increased costs for the user - Reduction of water in streams and lakes - Land subsidence : a loss of support below ground - Deterioration of water quality Pros of Dams - ANSWERS- hydroelectric power - controlling waterways - great source of irrigation - environmental protection Cons of Dams - ANSWERS- risk of sediment buildup - damaging to environment - erosion of surrounding soil - high cost and risk for disaster Consumptive Water Use - ANSWERSWater use in which the water is lost to the ecosystem Non-Consumptive Water Use - ANSWERSWater use that recycles and doesn't use up the water supply Irrigation used by farmers - ANSWERSWasteful and Non-Wasteful Wasteful Irrigation Methods - ANSWERS- Overhead sprinklers - Trench irrigation - Flood irrigation Non-Wasteful Irrigation Methods - ANSWERS- Drip Irrigation Water scarcity affects... - ANSWERSApproximately 2 billion people Water Scarcity/Stress - ANSWERSThe total # of people living in a country determines the per capita availability of water resources in that country Population growth is... - ANSWERSA major contributor to water scarcity Agricultural Uses of Water - ANSWERS- irrigation: ~ overhead sprinklers ~ trench irrigation ~ flood irrigation ~ drip irrigation Industrial Uses of Water - ANSWERS- power plants - oil refineries - manufacturing Recreational Uses of Water - ANSWERS- swimming - fishing - boating - golf courses Land Subsidence - ANSWERSThe gradual settling and lowering of the Earth's surface Land Subsidence occurs when... - ANSWERSLarge amounts of groundwater have been withdrawn from certain types of rocks, such as fine-grained sediments. Causes of Land Subsidence - ANSWERS- Most often caused by human activities, mainly from removal of subsurface water - Compaction of soils in some aquifer systems can accompany excessive groundwater pumping Effects of Land Subsidence - ANSWERS- Permanent reduction in the total storage capacity of the aquifer system - Permanent Subsidence and related ground failures Saltwater Intrusion - ANSWERSThe induced flow of seawater into freshwater aquifers primarily caused by groundwater development near the coast Causes of Saltwater Intrusion - ANSWERS- Lateral encroachment from coastal waves - Vertical upcoming near discharging wells Effects of Saltwater Intrusion - ANSWERS- Decreases freshwater storage in aquifers - Can result in abandonment of supply wells