Determination and mapping of actual evapotranspiration using remote sensing technique and SEBAL Approach (Case Study: Manshad catchment, Yazd Province)

A large portion of volumetric catchments, water wastes through evapotranspiration (ET). Therefore، investigation and monitoring of spatio-temporal changes of ET would illustrate the amount of applied water in each land use unit, and also would help to proper management and allocation of water in a catchment scale. In such scales, generation of an ET map over the catchment would more applicable compared with point wise calculation of ET at some meteorological stations. Main objective of this study is introducing of Surface Energy Balance Algorithm for Land (SEBAL) as a new procedure for estimation of actual ET in from of a pixel by pixel basis map. In this study a time series of MODIS satellite images from Manshad catchment in Yazd province were acquired during 2006-2007 cropping season and used for generation of actual ET map. Results of this study show the adequacy of SEBAL in estimation of actual ET under the studied condition. Spatial distribution of ET also indictae that water demand of each land use unit is different comopared with other unit (varies from 27 to 1174 mm، spatially). The generated ET map would help for site specific application of water in the region and therefore, proper management of water resources in a catchment scale