Evaluation and Comparison of Estimation Methods for Actual Evapotranspiration in the Urmia Lake Basin

Actual evapotranspiration is one of the main variables in calculating the water balance and land surface energy. Different methods for calculating actual evapotranspiration have been presented so far. The purpose of this study was to investigate and compare various existing methods for estimating actual evapotranspiration in the Urmia Lake basin in order to select an optimal algorithm. Using the ETLook, SEBAL, SEBS and S-SEBI algorithms based on the energy balance equation, the results obtained by comparing the results of different algorithms showed that the ETLook method has been able to utilize the latest methods of estimation of evapotranspiration. Many The failings of other algorithms are covered. This two-source method analyzes vegetation and soil separately, using soil moisture images, has not even been able to withstand its efficiency in calculating evapotranspiration, even on cloudy days. However, the commercialization of this algorithm and the great difference in the results of the global WaPOR product (produced with ETLook) with ground observations in the Urmia Lake basin has made it less and less convenient to use. Considering all the conditions, including having a suitable physical base, ease of implementation and comparison with ground values, it can be admitted that the SEBAL algorithm is the most suitable option for estimating the actual evapotranspiration of the Urmia Lake basin.