Simulation of the catchments hydrological processes in arid, semi-arid and semi-humid areas

Hydrological processes and their spatial distribution directly are relevant to climate, topography, geology, and land use in the watershed. Therefore, use of a model whit integrity and high performance for simulating the process in deferent watersheds is very important. In this study was assessment performance of semi-distributed SWAT model in simulating hydrology processes in three watersheds with different climate: Jazmurian basin with 1258 (km2) in an arid climate, Khorramabad watershed white 2467 (km2) in a semi-arid climate and Talar watershed white 2057 climate in semi-humid climate. To this purpose, maps land use, soil, digital elevation model, and meteorological data in daily step collected from many stations for each region. After running the SWAT model, the calibration and validation model did whit SUFI2 algorithm. Performance models were assessed with statistical coefficients NS, R2 and bR2. The results showed that the values of these coefficients in Jazmurian basin is 0.56, 0.54 and 0.20, in Khorramabad watershed is 0.68, 0.72 and 0.32 respectively and in Talar watershed is 0.64 0.66 and 0.31 respectively. Overall, the results showed that the SWAT model performance in Talar watershed is higher than the other watersheds.