Groundwater-related subsidence in the context of "Overdrafting"

An aquifer is an underground layer of water-bearing material consisting of permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related concepts include aquitard, a bed of low permeability along an aquifer, and aquiclude (or aquifuge), a solid and impermeable region underlying or overlying an aquifer, the pressure of which could lead to the formation of a confined aquifer. Aquifers can be classified as saturated versus unsaturated; aquifers versus aquitards; confined versus unconfined; isotropic versus anisotropic; porous, karst, or fractured; and transboundary aquifer.

Groundwater from aquifers is sustainably harvested by humans through the use of qanats leading to a well. This groundwater is mainly used for agricultral purposes but is used for other reasons such as home use, industrial use and is sometimes used as a source of renewable energy. Groundwater is a major source of fresh water for many regions, although it can present various challenges for the environment, such as overdrafting (extracting groundwater beyond the equilibrium yield of the aquifer), groundwater-related subsidence of land, and the salinization or pollution of the groundwater.

Overdrafting is the process of extracting groundwater beyond the equilibrium yield of an aquifer. Groundwater is one of the largest sources of fresh water and is found underground. The primary cause of groundwater depletion is the excessive pumping of groundwater up from underground aquifers. Insufficient recharge can lead to depletion, reducing the usefulness of the aquifer for humans. Depletion can also have impacts on the environment around the aquifer, such as soil compression and land subsidence, local climatic change, soil chemistry changes, and other deterioration of the local environment.

There are two sets of yields: safe yield and sustainable yield. Safe yield is the amount of groundwater that can be withdrawn over a period of time without exceeding the long-term recharge rate or affecting the aquifer integrity. Sustainable yield is the amount of water extraction that can be sustained indefinitely without negative hydrological impacts, taking into account both recharge rate and surface water impacts.

An aquifer is an underground layer of water-bearing material consisting of permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related concepts include aquitard, a bed of low permeability along an aquifer, and aquiclude (or aquifuge), a solid and impermeable region underlying or overlying an aquifer, the pressure of which could lead to the formation of a confined aquifer. Aquifers can be classified as saturated versus unsaturated; aquifers versus aquitards; confined versus unconfined; isotropic versus anisotropic; porous, karst, or fractured; and transboundary aquifer.

Groundwater from aquifers is sustainably harvested by humans through the use of wells. This groundwater is mainly used for agricultral purposes but is used for other reasons such as home use, industrial use and is sometimes used as a source of renewable energy. Groundwater is a major source of fresh water for many regions, although it can present various challenges for the environment, such as overdrafting (extracting groundwater beyond the equilibrium yield of the aquifer), groundwater-related subsidence of land, and the salinization or pollution of the groundwater.