Comparison of SEBS and Penman-Monteith methods in estimating water requirement of corn crop (Case study: Meshginshahr)

Determining the water requirement of agricultural products is one of the most important ways to achieve water management efficiency. Therefore, the main purpose of this study is to estimate the water requirement of corn in Meshginshahr, Ardabil province. For this purpose, 10 cloudless images of Landsat 8 satellite from 2004 to 2016 and the SEBS method were used. The results were compared with Penman-Monteith and evaporation pan methods. The results showed that in the SEBS method the water requirement of corn crop on 2010.8.3was equal to 8.14 mm/day and on 2015.11.30 equal to 1.09 mm/day and in Penman-Monteith method on 2013.7.19 equal to 9.94 mm/day and on 2015.11.30 equal to 3.12 mm/day, which has the highest and lowest actual evaporation and transpiration, respectively. SEBS method has the highest error rate with RMSE equal to 1.466 and MAD equal to 1.325 mm/day compared to evaporation pan. SEBS method has the lowest error rate with RMSE equal to 1.199 and MAD equal to 0.947 mm/day compared to the Penman-Monteith method. Also, by examining the values of the coefficient of determination, it was found that the SEBS method has the highest coefficient of determination (0.8677) with the Penman-Monteith method and then with the evaporation pan method (0.8247).