Grondwater and Overuse
Groundwater Use and Overuse
The biggest reservoir of fresh, liquid water on earth is groundwater. There is more than 20 times as much water stored within the ground as in all the lakes and rivers combined. In many parts of the world, agricultural, industrial, and domestic water demands can only be met by pumping water out of the ground.
As you'll see in the diagram below, wells work only if they penetrate the water table - the name given to the subsurface boundary that separates saturated and unsaturated ground. Above the water table, cracks and spaces between soil and rock particles contain at least some air. Infiltrating water moves more or less vertically as it passes through this unsaturated zone. Below the water table, all openings in the ground are filled with water. Once groundwater reaches this saturated zone, it begins to travel both horizontally and downward, and can flow into wells, rivers, and eventually the sea.
The water table is an irregular surface that generally resembles a gentler version of the overlying ground surface. It is not fixed, but moveable, rising when rainfall adds more water to the ground, and falling when drought reduces the water supply. The depth and shape of the water table can also change dramatically when groundwater is pumped out of the ground. Pumping can quickly draw down the local water table right around a well. Over time, excessive pumping can also lower the water table over a wide region. DRAWING
Groundwater
The importance of groundwater for the existence of human society cannot be overemphasized. Groundwater is the major source of drinking water in both urban and rural India. Besides, it is an important source of water for the agricultural and the industrial sector. Water utilization projections for 2000 put the groundwater usage at about 50%. Being an important and integral part of the hydrological cycle, its availability depends on the rainfall and recharge conditions. Till recently it had
The biggest reservoir of fresh, liquid water on earth is groundwater. There is more than 20 times as much water stored within the ground as in all the lakes and rivers combined. In many parts of the world, agricultural, industrial, and domestic water demands can only be met by pumping water out of the ground.
As you'll see in the diagram below, wells work only if they penetrate the water table - the name given to the subsurface boundary that separates saturated and unsaturated ground. Above the water table, cracks and spaces between soil and rock particles contain at least some air. Infiltrating water moves more or less vertically as it passes through this unsaturated zone. Below the water table, all openings in the ground are filled with water. Once groundwater reaches this saturated zone, it begins to travel both horizontally and downward, and can flow into wells, rivers, and eventually the sea.
The water table is an irregular surface that generally resembles a gentler version of the overlying ground surface. It is not fixed, but moveable, rising when rainfall adds more water to the ground, and falling when drought reduces the water supply. The depth and shape of the water table can also change dramatically when groundwater is pumped out of the ground. Pumping can quickly draw down the local water table right around a well. Over time, excessive pumping can also lower the water table over a wide region. DRAWING
Groundwater
The importance of groundwater for the existence of human society cannot be overemphasized. Groundwater is the major source of drinking water in both urban and rural India. Besides, it is an important source of water for the agricultural and the industrial sector. Water utilization projections for 2000 put the groundwater usage at about 50%. Being an important and integral part of the hydrological cycle, its availability depends on the rainfall and recharge conditions. Till recently it had