SWAT Model Application for Simulating Monthly Runoff, Lake Urmia Watershed, Kurdistan Province, Iran

The Soil and Water Assessment Model (SWAT) is a continuous and semi-distributed model. The SWAT model is capable of being connected to the Geographic Information System (GIS). Using a range of information such as basin physical information (soil, land use and slope) as well as meteorological information such as rainfall, temperature, wind, relative humidity and solar radiation, this model can monitor hydrological processes in catchments on a daily time scale., Monthly and yearly. Simulation of hydrological processes in watersheds is essential for predicting future events in those basins and identifying ways to deal with them. In this study, using SWAT hydrological model, the runoff outflow of Santeh hydrometric station in the watershed of Lake Urmia in Kurdistan province in Iran with an area of ​​5306 km2. Runoff simulation was performed over a seven-year statistical period 2007-2013. The first five years of this period 2007-2011 for model calibration using 21 different parameters and the final two years of 2011 and 2012 for validation using two statistical indices (NSE) and coefficient of determination (R2). it placed. According to the simulated hydrograph and the monthly runoff observations, the calculated statistical indices of SWAT model in the calibration period and in the monthly time scale validation period have acceptable results in the runoff simulation, with coefficient values ​​(NSE) and (R2) in the calibration period were 0.78 and 0.82 respectively and for the validation period 0.9 and 0.91 respectively.