From single to compound hazards: how flood and drought vulnerabilities have intensified across India

Floods and droughts are intensifying and increasingly co-occurring under hydroclimatic variability, yet vulnerability assessments typically consider these extremes in isolation, masking compounded risks. Here, we develop a unified framework to quantify district-scale vulnerability to floods, droughts, and their combined impacts across India. Central to the framework is the Multi-Hazard Vulnerability Index (MHVI), supported by a bivariate vulnerability classification that explicitly captures overlapping susceptibilities to opposing hydrological extremes. Applying the framework for 2001 and 2011 reveals a substantial escalation of vulnerability, with highly flood-vulnerable districts increasing from 16.5% to 21.4% and drought-vulnerable districts from 10.6% to 18.1%, alongside a growing concentration of multi-hazard hotspots in eastern and northern India. The results demonstrate pronounced spatial and temporal shifts in compound vulnerability, highlighting regions where development gains are increasingly exposed to multi-hazard risks. The scalable framework offers a robust basis for risk-informed adaptation planning, resource prioritization, and climate-resilient disaster risk reduction.