Hydrological modelling of ungauged urban watershed using SWAT model

Abstract

The effects of urbanization on hydrological processes and water resources have been quantified and predicted by detailed characterization and modeling of the affected urban area. The model of the soil and water assessment tool (SWAT) has been selected to test its applicability in ungauged urban watershed of Vadodara city, Gujarat India. The main objective of this work is to study the SWAT model and its applicability i.e. test and assess the capabilities, and performance of SWAT model for Vadodara city, which is ungauged urban area by simulating the water balance components in order to understand the status of hydrological process and water resources in that area. The Vadodara city watershed is ungauged. Therefore, a regionalization approach has used to predict the river discharge at the outlet of the watershed. SUFI-2 algorism using SWAT-CUP2012 used for calibration and validation of runoff process has been done on monthly basis. The model was calibrated and validated based on the comparison of simulated and observed flow rates at the basin outlet for the periods 1979–2001 and 2002–2013 respectively. Therefore, for the monthly time step, the application of the NSE values was 0.53 and 0.61, the determining coefficient (R2) was 0.69 and 0.51, while the value of PBIAS was 5.3 and 10.4%, and RSR values were registered as 0.71 and 0.63 for the periods of the calibration and validation process respectively. The result suggests that there has been a good match between simulated and observed flow. Therefore, the model performance is applicable and strong predictive ability for the ungauged watershed of Vadodara city.