Water Conservation in Arid Zones

Abstract

Water conservation is a special form of water management for water-short areas, where water must be used as efficiently as possible and water losses must be minimized. A water loss is defined as the transfer of water to a place or condition from which it cannot readily be recovered for further use. Such losses include evaporation and transpiration, discharge of fresh water into salt water (oceans, lakes, or aquifers), storage or transit in the vadose (unsaturated) zone, and serious pOllution by industrial, agricultural, or other chemicals. These are true losses of water. On the other hand, seepage of water from streams or irrigation canals to underlying aquifers is not always a realloss because the water can be recovered by pumping it from wells in the aquifers, or it may eventually drain into surface water. Yet, many irrigation canals are lined to “conserve” water. Thus, water conservation is best defined as water management to minimize transfer of water to a place or condition which diminishes its usefulness to the intended user. Water conservation can be achieved by reducing evaporation, transpiration, and quality degradation ; by cloud seeding ; increasing groundwater recharge or other storage ; seepage control ; and treating and reusing sewage or other contaminated water.