Application of the Sebs Water Balance Model in Estimating Daily Evapotranspiration and Evaporative Fraction from Remote Sensing Data Over the Nile Delta

Abstract

Estimation of evapotranspiration is always a major component in water resources management. The reliable estimation of daily evapotranspiration supports decision makers to review the current land use practices in terms of water management, while enabling them to propose proper land use changes. Traditional techniques of calculating daily evapotranspiration based on field measurements are valid only for local scales. Earth observation satellite sensors are used in conjunction with Surface Energy Balance (SEB) models to overcome difficulties in obtaining daily evapotranspiration measurements on a regional scale. In this study the SEB System (SEBS) is used to estimate daily evapotranspiration and evaporative fraction over the Nile Delta along with data acquired by the Advance Along Track Scanning Radiometer (AATSR) and the Medium Spectral Resolution Imaging Spectrometer (MERIS), and six in situ meteorological stations. The simulated daily evapotranspiration values are compared against actual ground-truth data taken from 92 points uniformly distributed all over the study area. The derived maps and the following correlation analysis show strong agreement, demonstrating SEBS' applicability and accuracy in the estimation of daily evapotranspiration over agricultural areas.