Comparison of Actual Evapotranspiration Estimated Using Gram-Schmidt Method and SEBAL Algorithm with Lysimeteric Data (Case study; Amir Kabir Sugarcane Argo-Industry)

One of the most important parameters of the water balance equation is evapotranspiration which is effective factor in the management of water resources. Also in different sciences it has been shown the transformation of hardware methods to software methods. One of these few cases is determination actual evapotranspiration using remote sensing and satellite images. According to the importance of actual evapotranspiration in the allocation of water resources in current research by using satellite images from Landsat 8 (suitable spatial resolution) and MODIS (acceptable temporal resolution) were determined the amount of mention parameter of sugarcane in Amir Kabir Sugarcane Argo-Industry and was compared with lysimeteric data. For this purpose, Landsat 8 and MODIS images were merged in the period of 16 days by Gram-Schmidt method and the actual evapotranspiration of sugarcane was estimated by SEBAL algorithm. In addition, the amount of actual evapotranspiration was calculated using Landsat8 images and SEBAL algorithms. Finally, the results of two mention methods were compared with lysimeteric data and were analyzed by statistical methods. The results indicated that the average of absolute difference between actual evapotranspiration of fusion images and lysimeteric method was 0.55 (mm/day). This index was 0.063 (mm/day) between Landsat 8 images and lysimeteric data and the average of absolute difference between two methods of remote sensing was obtained 0.58 (mm/day). Also at the level of five percent, there is not a significant difference between the two methods of remote sensing.