Hydrological Simulation of Taleqan Watershed Using SWAT

Hydrological modeling of watersheds plays a significant role in study, development and management of water resources. Based on importance of Taleqan Watershed as a main supplier of Alborz and Tehran Provinces water resources, in this study, surface water hydrological simulations in this basin are investigated.

Hydrological simulations were performed by applying physical semi-distributed SWAT (Soil and Water Assessment Tool) model. Moreover, model calibration and sensitivity analysis were done using SUFI-2 algorithm. Model performance is evaluated by means of statistical indicators such as Nash-Sutcliffe (NS) and coefficient of determination (R2).

Sensitivity analysis showed that the parameters of the curve number (CN), soil evaporation compensation, and soil available water capacity are the most important factors to control the flow in the basin. At Gelinak station (watershed outlet), NS and R2 coefficients values after calibration are 0.84 and 0.87, respectively. These values in validation interval were obtained as 0.79 and 0.84.

The results show good performance of the watershed simulations. Moreover, it was shown that the model has good capability for monthly surface runoff prediction of the Taleqan basin. Due to reducing field operations costs of required components measurements and especially due to reducing the time required to analyze issues, applying this model is efficient for improving water resource management and environmental protection.