Estimation of Evapotranspiration ET and Crop Coefficient K of Wheat, in south Nile Delta of Egypt Using integrated FAO-56 approach and remote sensing data

Abstract

Crop water requirements are represented by the actual crop evapotranspiration. Estimation of crop evapotranspiration (ETc) and crop coefficient using remote-sensing data is essential for planning the irrigation water use in arid and semiarid regions. This study focuses on estimating the crop coefficient (Kc) and crop evapotranspiration (ETc) using SPOT-4 satellite data integrated with the meteorological data and FAO-56 approach. Reference evapotranspiration (ETo) were estimated using FAO Penman-Monteith and tabled single crop coefficient values were adjusted to real values. SPOT-4 images geometrically and radio metrically corrected were used to drive the vegetation indices (NDVI and SAVI). Multi linear regression analysis was applied to develop the crop coefficient (Kc) prediction equations for the different growth stages from vegetation indices. The results showed R2 were 0.82, 0.90 and 0.97 as well as adjusted R2 were 0.80, 0.86 and 0.96 for developing, mid-season and late-season growth stage respectively.