Impact evaluation and analysis at a river basin scale under projected climate and land-use change

Abstract

This study evaluated the individual as well as integrated impacts of climate and land use change on streamflow over Meenachil River Basin, Kerala, India. The hydrological model SWAT was used to simulate future streamflow simulations under representative concentration pathway (RCP) 4.5 and 8.5 scenarios for the medium term (2025–2055) and long term (2056–2086). The land use land cover change was projected using land change modeler (LCM) of TerrSet software for the future period. Climate model simulations were taken to predict future streamflow at the regional scale, and an attempt was made to reduce the uncertainty associated with future predictions. According to the findings, streamflow was influenced by climate change (68.07%) and land use change (31.92%), with climate change having a higher contribution rate. The findings suggest that the combined impact of climate and land use change would increase streamflow in the future. The annual average streamflow is expected to decline (5.9%) in the medium term (2025–2055) under RCP 4.5 scenario and rise by 5.3% under RCP 8.5 scenario with reference to the observed streamflow for the period 1987–2017. However, in the long term, it is expected to rise by 10.56% under RCP 4.5 and 22.61% under RCP 8.5.