Climate Change Impact on Water Resources in the Himalayan Region: A Coupled Modeling Approach

The estimation of climate change impact on water resources in the Himalayan region is imperative to achieve sustainability under the increasing threat of glacier loss. Studies have reported contrasting findings regarding the runoff and water availability in the Himalayan rivers, with some suggesting an increase in runoff and others indicating a decline. Climate change is also expected to lead to more extreme precipitation events, which can result in floods, landslides, avalanches, and GLOFs. The projected runoff is reported to decrease for basins contributed by small glaciers and increase for those contributed by large glaciers. Rising temperatures lead to more snow/ice melting and increased precipitation, both contributing to higher runoff generation until the glaciers are depleted. The uncertainties in regional hydroclimate projections are often associated with the uncertainties of precipitation from GCMs. To provide more realistic glacier extent for future projections, this study couples a state-of-the-art glacier model with hydroclimate and atmospheric models. However, due to limited computational resources, only one CMIP5 model output was considered in this study. Overall, this study investigates the impact of future projected climate change on the hydroclimate fluxes of the Beas basin and examines the plausibility of extremes in these scenarios over the 21st century.