Modeling High Aswan Dam Reservoir Morphology Using Remote Sensing to Reduce Evaporation

Abstract

Egypt is considered as an extremely arid country with annual rainfall under 200 mm within coastal zones. High Aswan Dam Reservoir (HADR) experiences high evaporation losses of 15 BCM/year on average. Meanwhile, the water demand is increasing due to rapid population growth. Hence, measurements must be taken to decrease its evaporation losses. This can be achieved through controlling evaporation losses from the shallow lagoons, locally known as khors. The first step in the control process is to model the lake morphology using topographic data. Topographic maps are available for the time span before the construction of the High Aswan DAM (HAD), but they have not been updated. Hence, this study utilized satellite imagery since 1984 to develop a digital elevation model (DEM) that simulated the lake surface area. Correlated water levels were gained from the assembled hydrological database of HADR. This paper reports on the different alternatives for reducing the evaporation losses of two large khors, Kalabsha and El-Alaky, and two small khors, Korosko and Sara. It shows that the developed DEM allows estimation of the different hydrological features of HADR and its khors and recommends some measures to eliminate these khors to save up to 3 BCM by 2100 according to global climate model scenarios.