Formation of fresh ground-water lenses in northern Kuwait

In Kuwait, an arid country with a low annual average rainfall of about 115 mm, fresh ground-water lenses are found at Raudhatain and Umm Al-Aish fields, in the northern part of the country. These lenses are formed due to a combination of unique conditions that include short duration, high intensity rainfall; geomorphology; and lithology that enables rapid infiltration to the underlying ground-water. Large depressions and playas, paleodrainage patterns, and catchment areas, which are necessary for the accumulation of large amounts of water during flash foods, were mapped from aerial photographs, Landsat Thematic Mapper (TM) imagery, and digital elevation model (DEM) datasets. From historical pumping and water quality variation data acquired between 1963 and 1977, the sustainable extraction rate for Raudhatain and Umm Al-Aish is estimated to be 5•5 and 3•5 Ml day−1, respectively. These rates are fundamental to the delicate management required to extract freshwater from the lenses and yet avoid upconing of the deeper saline water.