Abstract
Shallow aquifers were exploited in western Saudi Arabia a long time ago in history. In the last five decades, and under the conditions of an increasing supply of water, many new wells were drilled at relatively deeper intervals than the hand-dug wells of the time. In the downstream part of Wadi Fatimah, and over time, more saline water has been brought up in a number of wells. Overexploitation of groundwater for industrial and agricultural purposes has led to the appearance of two phenomena responsible for the salinization-upconing and saline water intrusion. Upconing occurs in separate pockets while saline water encroachment affects the lower part of Wadi Fatimah and the area towards the Red Sea coast. This article deals with the identification and delineation of areas affected by each of the two phenomena. The methodologies used in this work are mainly hydrogeological and hydrochemical. Resistivity surveys helped in delineating the fresh water-saline water interface. Methods to control upconing and saline water intrusion are suggested to safeguard the aquifer from further contamination. Effective conservation measures are recommended for the protection of groundwater resources in Wadi Fatimah.