Hydrological Modeling of Pishin Dam Watershed using SWAT

Inter or Intra-basin water transfer schemes are gratually becoming popular for tacklilng the water shortage of a water-poor basin/region using the resources of a more water-abundant basin. However, assessment of the potentionals to accommodate the water needs of a basin using its available resources is the first step toward an effective management of water resources at regional scale. This would reduce the unnecessary costs and adverse impacts of transbasin diversion projects. Sarbaz River basin in Sistan and Baluchestan province, Iran, is one important basin that provides water to a large comunnity and its water is regulated through Pishin dam. In this study, we model the hydrologic cycle of Sarbaz river basin using the Soil and Water Assessment Tool (SWAT) to assess the inflow to Pishin dam reservoir. Calibration-validation and uncertainty assessment of the model was performed using the Generalized Likelihood Uncertainty Estimation (GLUE) technique in SWAT-CUP program. The monthly streamflow data of September 2004 to May 2010 and September 2010 to June 2014 were, respectively, used for model calibration and validation. Based on the Nash-Sutcliff model Efficiency (NSE) coefficient, results showed a very good performance with NSE of 0.77 and 0.76 during calibration and validation, respectively. Therefore, the developed SWAT model can be introduced as a powerful and reliable tool for studying the water cycle of the Sarbaz River basin to evaluate the managerial policies planned/implemented with relation to Pishin dam. It can also serve as a medium to study the climate change impacts on the streamflow of the watershed.

Keywords:

SWAT , GLUE , Sarbaz , Pishin Dam