Simulation of Rainfall-Runoff for Gharesou Watershed Using SWAT Model

Rainfall-runoff Simulation is very important in many hydrological studies, such as investigating the effects of climate change on river flow, flood prediction and planning of water resources. SWAT model was used to simulate stream flow transport, sediment and quality variables (nitrogen and phosphorus...) in the watershed areas. SWAT model is a distributed time series model with physical basis. This model has an ability to connect to GIS, in a way that vast volumes of data as information layers such as land use, soil map and the DEM using GIS capabilities are used by the model. The main purpose of this study is testing SWAT model performance as a simulator of flow at the catchment scale.
This study attempts to prepare a model for Gharesou catchment. Moreover, the parameters were optimized using SWAT-CUP optimizer.
Findings: The model was calibrated for the years 1992-1996 and validated for the years 1998-2000. The coefficient of determination (R2) for monthly flow was equal to 0.82 and Nash-Sutcliffe coefficient (Ens) was equal to 0.8 in the calibration period while in the validation period these coefficients were 0.77 and 0.73, respectively.
These results indicate the success of the SWAT model, using optimized parameters, for the stream flow simulation in Gharesou catchment.