Evaluation of remotely sensed precipitation data in runoff simulation for Kalam Basin, Hormozgan using SWAT

Runoff estimation is a fundamental activity in water resource management, and plays an important role in the best usage of a hydrologic system. Runoff estimation is usually based on different hydrological models. Calculation of intensity and duration of precipitation is not efficient in the most regions of the globe for determining general properties of precipitation because these calculations are based on pointed data of ground observation, whereas precipitation is a spatial phenomenon. The aim of this paper is simulating monthly runoff of Kalam Basin based on satellite data of precipitation using SWAT model. In order to running SWAT, precipitation data of TRMM and GPCP, temperature, relative humidity, wind speed and solar radiation is used for the period of 1998 to 2012 for study area. Also, soil and land use maps and DEM are converted to the model format for study area. Period 2001 to 2009 is used for calibration and 2010 to 2012 for validation of the model. Nash Sutcliffe Efficiency Index and Weighting Coefficient was 0.41, 0.44, 0.32 and 0.37 for TRMM and GPCP respectively for calibration and 0.52, 0.71, 0.10 and 0.19 for validation. The results indicated that SWAT achieved a reasonable fit after calibration by using TRMM and not reasonable using GPCP data the model.