GEOLOGY

Detailed explanation-1: -The remaining 3% of the water is in the form of ice sheets, glaciers, and is also present under the ground. A very small percentage is available as fresh water for human use. Q. About 97% of water on earth’s surface is found in .

Detailed explanation-2: -Groundwater accounts for 0.68 percent of total water. Rivers account for 0.0001 percent of the total water. Freshwater lakes make up 0.009 percent of water while inland seas and salt lakes make up an equal percent of the earth’s water. The atmosphere, on the other, hand holds 0.0019 percent of earth’s water.

Detailed explanation-3: -Topography and geology are the dominant factors controlling groundwater flow. Storativity describes the property of an aquifer to store water. Hydraulic conductivity is measured by performing a pumping test, i.e. by pumping one well and observing the changes in hydraulic head in neighboring wells.

Detailed explanation-4: -Stressors that can deplete aquifers include changes in precipitation and snowmelt patterns; withdrawal of ground water for drinking, irrigation, and other human uses; and impervious paved surfaces that prevent precipitation from recharging ground water. Some deep aquifers may take thousands of years to replenish.

Detailed explanation-5: -Fluctuations in the water table level are caused by changes in precipitation between seasons and years. During late winter and spring, when snow melts and precipitation is high, the water table rises. There is a lag, however, between when precipitation infiltrates the saturated zone and when the water table rises.