Comparison of Single-Site and Multi-Site Based Calibrations of Swat in Taleghan Watershed, Iran

Calibration of model is a critical role for hydrologic modeling in a large mountainous watershed. inthis study, soil and water assessment tool (swat) was calibrated in single-and multi-siteapproaches to simulate streamflow. in single-site calibration, a streamflow measurement at outlet ofwatershed was used for calibration of swat. whereas in multi-site calibration approach, we usedstreamflow measurements at three stations namly galinak, joestan and dehdar stations. the resultsshowed that the single-site calibration was able to sufficiently simulate the streamflow for galinak,joestan and dehdar stations (nash-sutcliffe criteria (ns: 0.66–0.81). the results of multi-sitecalibration method also showed slight improvement in galinak, joestan and dehdar stations, whereas it was improved in upper stations i.e. joestan and dehdar (ns: 0.70–0.82). but, in validation period, there were clearly adventage of results provided using multi-site calibration procedure (ns: 0.78, 0.63 and 0.64 for galinak, joestan and dehdar stations, respectively) compared to single-site calibration method (ns: 0.74, 0.61 and 0.50 for galinak, joestan and dehdar stations, respectively). the results of this study showed that the multi-site calibration method improved calibration of swat.