Overdrafting

Overdrafting is the process of extracting groundwater beyond the safe yield or equilibrium yield of the aquifer.

Since every groundwater basin recharges at a different rate depending upon precipitation, vegetative cover and soil conservation practises, the quantity of groundwater that can be safely pumped varies greatly among regions of the world and even within provinces. Some aquifers require a very long time to recharge and thus the process of overdrafting can have consequences of effectively drying up certain sub-surface water supplies.

Effects on climate

Aquifer drawdown or overdrafting and the pumping of fossil water increases the total amount of water within the hydrosphere subject to transpiration and evaporation processes, thereby causing accretion in water vapour and cloud cover, the primary absorbers of infrared radiation in the earth's atmosphere. Adding water to the system has a forcing effect on the whole earth system, an accurate estimate of which hydrogeological fact is yet to be quantified.

Socio-economic effects

Scores of countries are overpumping aquifers as they struggle to satisfy their growing water needs, including each of the big three grain producers—China, India, and the United States. These three, along with a number of other countries where water tables are falling, are home to more than half the world’s people.^[1]

Water is an intrinsic to growth ^[2]. Overdraft limits the availability of supply.

See also

• Groundwater recharge
• Groundwater-related subsidence
• Drinking water
• Water crisis

References

1. ^ Aquifer Depletion [1]
2. ^ Water and crop yield [2]

External links

• The Perils of Groundwater Pumping, Issues in Science and Technology
• Groundwater Depletion, USGS Water Science