Hydrologic response to climate change: A case from a high-mountain river basin

Water resources in the Himalayan region are highly exposed and vulnerable to climate variability and climate change. We investigate the potential impact of climate change on hydroclimatic extremes and spatiotemporal distribution of water balance components of the Himalayan river basin, taking the Tila River Basin of Nepal as a test site. This study integrates CMIP6 climate model outputs with a semi-distributed hydrologic model to produce streamflow projections. We analyze climate change impact in three timeframes: near (2026-2050), mid (2051-2075), and far (2076-2100) future under SSP 245 and SSP 585 scenarios. Results showed that the projected change in precipitation, evapotranspiration, and water yield is as high as 50%, 45%, and 75%, respectively. Both low and high flows are projected to increase under future climate scenarios. High altitude regions, with dominant snow- and glacier-covered areas, are more vulnerable to climate change impact. Our results are of practical importance for planners and decision-makers to formulate adaptation strategies under a changing climate.