Atef Swelam, Ajit Govind , Mohamed Abdallah , Pasquale Steduto and Ahmad Taha .( 2019). VALIDATION OF REMOTE-SENSING EVAPOTRANSPIRATION DATA OF SELECTED CROPS IN THE NILE DELTA3rd World Irrigation Forum (WIF3) 1-7 September 2019, Bali, Indonesia
Abstract: Evapotranspiration is a vital component of the water balance in arid regions and is a very important indicator of agricultural production. Many RS-based estimates are available for regional planning and policy development, but they are not rigorously validated. We conducted a study to validate the ET estimated using standard RS-based modelling platforms (WaPOR and SSEBop) using insitu monitored ET fluxes in different crops in the Nile Delta. We found that the trends and magnitudes agree but there are significant differences between the ET estimated using RS approaches and the one observed on the ground. The complex canopies architecture, such as orchards, have the biggest uncertainty vis-à-vis the nature of model parameterizations and the uncertainties in various RS-derived inputs used. In general, the orchards showed a large under estimation of ET as opposed to field crops. While SSEBop appears to perform better than WaPOR for the presented cases, there is a need for further validated using more insitu measurements and in-depth analysis of the causes of divergence.
Keywords: (Evapotranspiration, Nile Delta, Arid Ecosystems, SSEBop, WaPOR, ET measurements, Validation of RS-based ET with Insitu Measurements .)
