Ecology, Environment and Conservation Paper

CALIBRATION AND UNCERTAINTY ANALYSIS OF HUSSAINSAGAR WATERSHED USING SWAT-CUP, SUFI -2 APPROACH

Padmaja G. and Giridhar M.V.S.S

Abstract

Simulation of process-based hydrological models is a significant process and can be better interpreted by calibration and validation of these models. In the present study, SWAT model was chosen to simulate the hydrologic processes of Hussainsagar watershed followed by calibration and validation for monthly time steps using the SUFI-2 approach. Several trials were initiated to achieve a good correlation between the observed and simulated values as each objective function is sensitive to certain parameters. The goodness of fit was further assessed using the coefficient of determination (R2) and Nash–Sutcliffe Efficiency (NS) between the observed and final simulated values. The results have shown a good correlation between observed and simulated discharge values with R2 =0.97 and NS = 0.96, for calibration period and with R2 =0.99 and NS = 0.97 for the validation period for monthly time steps. After performing calibration followed by validation, the influence of each parameter considered was ranked with the help of global sensitivity analysis present in the SWAT-CUP. The overall study revealed that the ArcSWAT can be used efficiently to study the behavior of an urban watershed having varied hydrology, also determine the trend in the rainfall pattern for daily and monthly periods. The results obtained have shown a good correlation and would be helpful to the hydrological community for adopting better water management practices and in designing better infrastructure.