Lake Nasser evaporation reduction study

This study aims to evaluate the reduction of evaporation of lake nasser’s water caused by disconnecting (fully or partially) some of its secondary channels (khors). this evaluation integrates remote sensing, geographic information system (gis) techniques, aerodynamic principles, and landsat7 etm+ images. three main procedures were carried out in this study; the first derived the surface temperature from landsat thermal band; the second derived evaporation depth and approximate evaporation volume for the entire lake, and quantified evaporation loss to the secondary channels’ level over one month (march) by applied aerodynamic principles on surface temperature of the raster data; the third procedure applied gis suitability analysis to determine which of these secondary channels (khors) should be disconnected. the results showed evaporation depth ranging from 2.73 mm/day at the middle of the lake to 9.58 mm/day at the edge. the evaporated water-loss value throughout the entire lake was about 0.86 billion m3/month (march). the analysis suggests that it is possible to save an approximate total evaporation volume loss of 19.7 million m3/ month (march), and thus 2.4 billion m3/year, by disconnecting two khors with approximate construction heights of 8 m and 15 m. in conclusion, remote sensing and gis are useful for applications in remote locations where field-based information is not readily available and thus recommended for decision makers remotely planning in water conservation and management.