Climate change-driven hydroclimatic shifts and energy prospects: Insights from a snow-fed river basin in Western Himalaya

Abstract

Climate change is a multifaceted process having significant consequences for hydrological process such as river flow and resultant ecosystem services such as hydropower generation. The fragile mountain ecosystems are particularly more sensitive to climate change, and therefore, understanding their responses is essential for sustaining the water and energy security. However, limitation in data availability poses challenges in comprehensive evaluation of watershed responses. Here, we employed hydrological modelling-based approach for assessing the hydrological response and hydropower potential in a data-scarce Himalayan watershed (Upper Beas River) to climate change scenarios. Using gridded precipitation data and station streamflow observations, the Soil and Water Assessment Tool (SWAT) model was employed to simulate the climate change impact on flow processes in the catchments. For assessing the climate change impacts, an ensemble of 13 GCMs was analysed for trends and shifts in climate variables. An increasing trend in the precipitation and streamflow were observed for all climate scenarios; however, the increase in streamflow was disproportionate in different seasons linking to the change in seasonal flow components. In general, the monsoon flows are expected to increase due to higher rainfall, but a shift in the snowmelt contribution (from late spring to early spring) is noticed. Percentile exceedance (75^th, 95^th and 99^th) probability of daily extreme events showed higher frequency in future timescale. Further, the hydropower potential of the catchments also indicated increasing trend throughout the 21^st century. This study comprehensively evaluates various climate change scenarios, enhancing our understanding of their potential impacts on the hydrological cycle.