Estimation of evapotranspiration of oak forest cover using SEBAL algorithm in the Robat Mahidasht region of Kermanshah, Iran

Oak (Quercus spp.) forest cover is one of the most important living ecosystems in the western region of Iran and the Kermanshah Province. One of the important managerial needs of this cover is the water requirement of the oak plant. Currently, determining the amount of water required by the oak plant is one of the main priorities of the country's natural resources sector. Among the practical methods for estimating the evapotranspiration of vegetation (water requirement) at different levels are remote sensing techniques. In this study, in order to determine the rate of evapotranspiration of forest cover in the Robat Mahidasht region in the Kermanshah Province, the SEBAL algorithm and four images of Landsat 5 in the period of June, July, and august of 2010 were used. Then, using Sentinel satellite images, the forest areas of the Robat-Mahidasht region were extracted and matched with the calculated evapotranspiration map. Based on the obtained results, the average rate of 24-hour evapotranspiration of forest cover in the desired time period has varied between 3.4 to 5.09 mm. The correlation coefficient between the estimation of evapotranspiration by SEBAL and lysimetric measurement in Mahidasht region was about 0.9967 and the absolute difference between them was about 0.53 mm per day, which indicates an error of less than 10%. The estimation of SEBAL algorithm is acceptable. Remote sensing technique and the SEBAL algorithm can be used in the compression classification and even the health of forests if there is a suitable sequence of images and with the help of satellite data of other sensors such as Sentinelimages.