Evapo-transpiration estimation in Taleghan Drainage Basin using MODIS images and SEBAL model

Estimation of evapo-transpiration is necessary in cases such as irrigation planning، determining of evaporation of the water bodies، water balance assessment، estimation of runoff and watershed management and ecological and meteorological studies. Evapo-transpiration can be determined precisely using field measurements. However، these methods provide evapo-transpiration just for limited areas from spatial point of view. This limitation has motivated the development of using remote sensing data to evaluate evapo-transpiration over vast area. Surface Energy Balance Algorithm for Land (SEBAL) is a new model that has been used at different areas all over the world for estimating of evapotranspiration. Due to the fact that no written report in evapo-transpiration estimation using this algorithm in the country has been published yet، the objective of this study is to investigate the validation of revised SEBAL model in mountainous region. In this project، actual evapo-transpiration values were estimated using MODIS image data and revised SEBAL model for mountainous region in 22 different dates in 2006 in Taleghan Drainage Basin. The result showed that the correlation between estimated and measured values is significant (R2=0. 88، p<0. 001). Thus، MODIS image data and revised SEBAL model were able to estimate actual daily evapo-transpiration values in Taleghan Drainage Basin. Therefore this revised algorithm could recommend as suitable method for further studies in different area with variation topography.