Hala Mosaad Ibrahim Ebaid, Survey Research Institute, Researcher, hala_sri@yahoo.com
ABSTRACT
Remote sensing and GIS technologies with aerodynamic principles have been integrated to estimate evaporation from Lake Nasser. The Moderate Resolution Imaging Spectroradiometer (MODIS), onboard the NASA Terra Earth Observing Satellites images have been used for surface temperature determining, specifically MOD11_L2, Land surface temperature (LST) image. Also a GIS Raster Calculator model technique for storing and processing the raster data, which applied Aerodynamic equations on 4 LST MODIS images, was used for evaporation calculation. Applying and rerunning the model on the four MODIS images showed that the evaporation rate varies from one month to the other throughout the lake, thus ranging from. 5-8 mm/day in February ,9-15 mm/day in May, 17-26 mm/day in August , and 9-12 mm/day in October. As for the evaporation values that represented the 4 seasons of this same year i.e. winter, spring, autumn, summer were 1.50, 2.67, 2.86 and 4.75 billion cubic meter respectively. Hence this summed up value of 11.78 billion cubic meter per year, obtained by applying this technique was slightly higher as compared to that obtained in the year 2005(10.58 billion cubic meter), using pan evaporation method. Evaporation using satellite imagery data, GIS model, and applying Aerodynamic principle could be a promising and reliable technique which is easy to handle and capable for aiding decision making.
KEYWORDS: Remote sensing, MODIS, lake Nasser