Estimation of Actual Evapotranspiration with Mountain SEBAL Method in Meshginshahr Region

Abstract evapotranspiration have the essential role in water balance, accurate estimates on many projects and scientific studies in the fields of hydrology, agriculture, industry, water engineering and other allied sciences, for efficient management of water resources and the design of hydraulic structures required. In recent years expanded use of satellite imagery in estimating real evapotranspiration, methods have been developed such that they can be SEBAL method mentioned. SEBAL model for estimating evapotranspiration in the study- the actual evapotranspiration in the study area (Meshginshahr region) was selected. This model has been implemented in many countries and it has achieved remarkable results. These models are generally designed for flat areas and the impact of altitude, slope and is ignored in the calculation. In this study, the involvement of these factors in the model, the new model called “Mountain SEBAL “has been introduced. Meshginshahr region in northwestern Iran with respect to an appropriate specification for the model selection and the calculation of the inputs to the model are: layer DEM, Slope, aspect, incoming  sun, the sun angle Cosine, Radiance spectral reflectance, kind of surface, the incident radiation, the normalized vegetation index, surface radiation surface temperature, outgoing longwave radiation, incident longwave radiation, soil heat flux, sensible heat flux and latent heat flux to calculate the evapotranspiration actual moment have been studied in the region. By comparing the normalized surface temperature and vegetation index (NDVI) -0.969 correlation was observed between them. The comparison between evaporation-actual evapotranspiration calculated vegetation indices, indicating the applicability of these two factors together (correlation of 0.81), so that areas with high vegetation density, with areas of evapotranspiration and high real comply. On the other hand, compared to images of surface temperature and actual evapotranspiration inconsistency confirms them as areas of high surface temperatures and evapotranspiration are down.