Estimation and assessment of actual evapotranspiration using remote sensing data (Case study: Tamar basin, Golestan province, Iran)

Evapotranspiration is one of the most important determinants of the hydrological cycle and surface energy balance. In fact Evapotranspiration cause the relationship between such as atmosphere and earth important elements. Most methods that have been presented use point measurements to estimate evapotranspiration. These methods are only suitable for the Local areas due to dynamic and changing nature of regional evapotranspiration are not generalizable to the Basin. Remote sensing has the capability to estimate and to assess the amount of evapotranspiration and its spatial distribution. Surface energy balance algorithm for land (SEBAL) is a new algorithm for estimating evapotranspiration in most parts of the world and other heat fluxes at the surface and have a satisfactory results. In this research evapotranspiration results derived with SEBAL algorithm was compared with FAO evapotranspiration standard method. The results indicate that the algorithm SEBAL determine the actual evapotranspiration in a large area without the need for more meteorological data. The results show that the obtained rate of evapotranspiration in SEBAL algorithm has less than the Penman – Monteith about 1-1.5 mm/d.