Water resources in Saudi Arabia with particular reference to Tihama Asir province

Although Saudi Arabia has made great progress in almost all aspects of development, the availability of water has remained problematic. It is, therefore, important to study water resources, and also the increasing water demands in Saudi Arabia in general, and in Tihama Asir in particular. Climate is influenced to a limited extent by the relatively high altitude of the mountains, especially where rainfall is concerned, and an annual average between 30mm and 300mm is recorded. The rate of evaporation, however, is very high, because of the cloudless sky and high temperatures. Runoff occurs only after torrential and monsoon rain, when the wadis collect floodwaters from their many tributaries. Two hundred dams have been built in recent years in an attempt to increase underground water recharge, and to provide potable water in sufficient quantity and quality, and to provide for irrigation. The ground water resources, including the shallow aquifers of wadis and the deep aquifers, could be of greater benefit with the modification of their current use. A large number of desalination plants have been constructed along the Red Sea and the Arabian Gulf to meet the increasing water demands of Saudi Arabia's increasing population. The utilization of treated sewage effluent should be increased to stop the threat of ground water contamination and to reduce the pressure exerted on available resources. Results indicate that modem irrigation methods reach high levels of average field irrigation efficiency, and traditional practices show the highest average levels of energetics performance. Based on water resources and water budget analysis the following recommendations are suggested to the Ministry of Agriculture and Water with regard to water uses in Saudi Arabia and Tihama Asir in particular.- Modernize traditional and intermediate irrigation methods on as many acres as feasible.- Introduce small green-houses on as many private farms as possible.- Develop water resources extension service programmes and training programmes that address fundamental aspects of improving domestic water use, and alternatives to natural and artificial supplies. The developed database can be used as an information source to support future water resource-oriented decision making