Evaporation estimation for Lake Nasser based on remote sensing technology

Lake Nasser in Upper Egypt is of a great importance for Egypt as it represents a large reservoir for the country’s freshwater resources. Precise studying of all elements contributing to the water balance of Lake Nasser is very crucial for better management of Egypt’s water resources. Evaporation is considered an important factor of the water balance system that causes a huge loss of the lake’s waters. In this study, evaporation rate for Lake Nasser is estimated using the surface energy balance approach based on remote sensing technology. Evaporation rate obtained from this method is instantaneous since it is estimated during the satellite overpass over the lake. However, evaporative fraction method is used to estimate the daily rate from the instantaneous one. The surface energy balance combined with remote sensing data proves promising to estimate evaporation rates for large water bodies. These could lead to more accurate monitoring of evaporation rates in the lake area without being dependent on field observations, which are sometimes unavailable or uncertain for these types of studies.