Intensifying precipitation extremes and shortened snow persistence reshape hydroclimatic risk in a Himalayan mountain basin

This study addresses the limited understanding of how interacting atmospheric extremes and cryospheric changes jointly influence infrastructure risk in high-mountain basins, where most assessments consider these processes independently. The objective of this study is to quantify the coupled impacts of climate extremes and snow cover dynamics on infrastructure exposure in the Baspa Basin, Western Himalaya, using an integrated basin-scale framework. The results show a significant warming trend (~ 0.34 °C per decade) and an increase in rainfall extremes (RX1day increase of ~ 10-20%), accompanied by a decline in snow cover duration (- 4 to - 7 days per decade), particularly at mid-elevations. Spatial analysis indicates that more than 60% of infrastructure is located in areas where increasing rainfall extremes coincide with reduced snow persistence, suggesting emerging compound hydroclimatic risk. These patterns suggest a shift toward increased rainfall-driven runoff and enhanced hydroclimatic variability. However, the results are subject to uncertainties associated with climate data resolution, snow cover estimation, and the assumption of static infrastructure distribution. By integrating atmospheric and cryospheric indicators with exposure analysis, this study provides a novel framework for assessing compound hydroclimatic risk, which may support climate-resilient infrastructure planning in high-mountain regions.