Projecting climate change impacts on streamflow in the Kunthi River Basin in Peninsular India with the SWAT model

The understanding of climate change is extremely important. A changing climate is likely to have an impact on hydrologic conditions affecting the livelihood of inhabitants and the economy of a region. In this study, the Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on the basin hydrology of a small, uncontrolled basin in Peninsular India. To establish a functional model, the soil, land use, and meteorological characteristics of the contemporary period (Calibration from 1991 to 1997 and Validation from 1998 to 2005) were used as the model input, and the model is calibrated and validated using the river gauging station at the basin outlet. The model performance was found to be reasonably accurate (NSE of Calibration is 0.59 and Validation is 0.57) with the model uncertainty within an acceptable limit (p-factor and r-factor for calibration and validation are 0.56, 0.56, and 0.61, 0.73, respectively). Once a functional rainfall-runoff model was established, projected climate data (2075–2088) about the worst greenhouse gas emissions scenario (RCP 4.5 and 8.5) were employed to predict the hydrological response. The results were compared with the baseline conditions (1984–2005). The findings suggest that (1) the climate is likely to be hotter and wetter, resulting in high discharge in wet seasons, (2) more pronounced low flow in the non-monsoon, and marked variation in the seasonal pattern of streamflow.