Over-exploitation of water: causes,consequences and solutions

     

.        The indiscriminate extraction of water resources, above the rechargeable levels of the aquifers is known as over-exploitation of fresh water,  meaning that more is taken out of the ground than can be sustainably replenished. Water which falls in the form of precipitation moves down into soil through rocks and gets accumulated as ground water. The layer of rock through which it parcolates is known as aquifers -- permiable water bearing rock and/ or sediment .Ground water found in two layers of soil : zone of aeration and zone of saturation. In the former soil gaps are filled by both of air and water,whereas in latter case it is filled by water only.

   The process of precipitation replenishing the ground water supply is called recharge.This ground water remains in a constant motion. About 5.97 quintillion gallon of ground water reside in the upper 2 km of earth's surface.

  Ground water can be extracted through Wells or bubbles up naturally through a spring and discharged in lakes or rivers to maintain the level of surface water. It is used for drinking, agriculture and recently groundwater levels have fallen in faster rate due to the diversion of above ground water, excessive extraction of water for irrigation and other uses. 

Causes of over-exploitation: 

(i) World population is ever-increasing, hence pressure on agriculture is continuing. More than 75% of fresh water is used in agriculture 

(ii IIlicit collection of water through illegal wells.

(iii) Extraction of water by machines and pumps.

Consequences :

   Depletion of ground water results in the increase of pumping cost, dry up of wells and rivers, intrusion of saline water in the coastal aquifers.

Solution 

  Use of waste water and ponding of excess river flows . Efficient operation on irrigation system, sustainable coservation of soil and water, changes of cropping pattern,etc are the important measures to replenishment of the ground water.