ABSTRACTION

The artificial removal of water from surface water or groundwater sources, commonly for agricultural or industrial use or human consumption. Excessive abstraction from rivers leads to reduced discharge, suspended load and bedload transport, and smaller channels downstream with often serious consequences for water quality and riverine ecology. Prolonged abstraction may cause water tables to fall, mineralisation of soil, degradation of vegetation and land subsidence. Excessive surface-water abstraction has been the major factor in the desiccation and hence lowering of the level and changes in salinity of the Aral Sea since the 1960s. Mismanagement of water abstraction from the rivers Amudarya and Syrdarya for irrigated agriculture has been partially reversed since 1997.

[See alsohuman impact on hydrology, irrigation, water resources]