ABSTRACT
As pointed out in the previous chapter, water is one of the essential ecosystem components for survival of all living species. The water component of the geoenvironment includes all rivers, lakes, ponds, inlets, wetlands, estuaries, coastal water, groundwater, and aquifers. These contribute as inputs to the oceans that make up 70% of the earth’s surface water. Water is required for many needs such as drinking, agriculture, cooking, domestic and industrial uses, transportation, recreation, electrical power generation, and support for aquatic life and other wildlife. Among the many underlying reasons for increasing water shortages are (a) demand in excess of supply, (b) depletion of aquifers, (c) lack of rain and other forms of precipitation, (d) watershed and water resources mismanagement, and (e) diversion of rivers. It is noted that irrigation requirements for agriculture are increasing. Estimates indicate that more than 70% of the world’s freshwater is utilized for agricultural purposes (Postel, 1999).
