Comparison of actual evapotranspiration obtained from lysimeter data and SEBAL algorithm in Kerman plain by use of MODIS sensor images

Determination of evapotranspiration in broad zones and within appropriate time intervals is an efficient tool for optimal management of water resources. SEBAL model is one of the algorithms, being paid much attention to in estimating evapotranspiration by use of satellite images. In this paper, we estimated the actual rate of evapotranspiration was estimated by use of fifteen elected images of MODIS sensor, belonging to year 1386, with the obtained results being compared with ground data recorded through region lysimeters. These studies were carried out in an area located on the Shahid Bahonar University farm (latitude and longitude of 30˚15˝N and 56̊58˝E) equipped with electronically weighing lysimeters and other meteorological parameter measuring devices. The acceptable results of RMSE, NOF and EF were obtained respectively about 0/62419, 0/09079 and 0/87636. Also, coefficient of determination (R2) of 0/71 between the observed and computational data was indicative of the fact that, this algorithm benefits from a high accuracy in estimating actual evapotranspiration. Following an estimation of the parameters of the Earth's surface temperature, albedo, vegetation cover indices, surface emissivity and net radiation (according to the separation of lysimeter pixel in the region), spatial distribution map of the daily evapotranspiration in the area was drawn.