Modelling Climate Change Impacts on Watershed Hydrology Using SWAT

Modelling climate change impacts is important for sustainable water management under changing climatic conditions. Soil and Water Assessment Tool (SWAT) is among the most used watershed-scale models for modelling climate change impacts. In this study, a review of the literature about the use of SWAT in climate change impact assessment is provided. The review was conducted on the articles published between the years 1998 and 2021 in journals listed in the Web of Science Core Collection. It classified the studies based on the geographical location, hydrologic variable investigated, climate model used, and emission scenario selected. The review also examined the challenges encountered during model development and applications. This analysis showed that the majority of the studies in the literature focused on simulation of streamflow for evaluation of changes in watershed hydrology. A few studies examined other water balance components, such as groundwater recharge, evapotranspiration, soil moisture. SWAT models were run in various watersheds over different continents by using a variety of global circulation models. SRES A1, A2 scenarios and RCP4.5 and RCP8.5 scenarios were the emission scenarios most studied. SWAT is advantageous over the other models, as it has robust theoretical background, straightforward application with user-friendly interface, and applicability under data-scarce conditions. Uncertainties in the hydrologic models and climate models and scenarios pose challenges for proper determination of climate change impacts at the watershed scale with SWAT.