Estimation of evaporation from the lake of the Aswan High Dam (Lake Nasser) based on measurements over the lake

Abstract

Monthly values of evaporation from the lake of the Aswan High Dam (Lake Nasser) were estimated by the heat budget and bulk aerodynamic methods, using average monthly estimates of different meteorological elements over the Lake based on measurements taken during survey trips over the Lake in different months of the period 1970–1971. Monthly evaporation was calculated as the average of estimates by both methods. Annual lake evaporation is about 7.4 mm day −1 with maximum evaporation in June (10.9 mm day −1 ) and minimum evaporation in January (3.8 mm day −1 ). The annual evaporation is about 13% higher than the annual incoming net radiation. At the average Lake surface level of 175 m above mean sea level, the total water loss by evaporation should not be more than 14 × 10 9) m 3, which is about 11% of the lake water content.