Mapping multi-hazard flood and drought risk in a rapidly growing region: A ward-level assessment in the Bengaluru Metropolitan Region, India

A B S T R A C T Hydrological extremes, such as floods and droughts are becoming increasingly frequent and severe under the influence of climate change, with rapidly urbanizing regions like South Asia facing particularly high risks. Moreover, the occurrence of these extremes is becoming more common, amplifying their overall impact through compounding effects. This study focuses on the Bengaluru Metropolitan Region (BMR), one of India’s fastest-growing urbanized regions with rising exposure to both flood and drought risks. Despite growing evidence of their interconnected and compounding impacts, traditional Disaster Risk Management frameworks continue to treat these phenomena in isolation. This study addresses this gap by developing a spatially explicit, multi-hazard risk assessment framework that integrates both flood and drought risks through a composite index approach. The framework combines biophysical parameters with socio-economic indicators to assess multi-hazard risk across the Bengaluru Metropolitan Region. Participatory-based weighting of exposure vulnerability indicators is applied to produce high-resolution maps of hazard, exposure, vulnerability, and risk at the micro-administrative scale. The findings reveal spatial overlaps between flood- and drought-prone areas, with the Bengaluru Rural district and peri-urban zones showing particularly high multi-hazard risk. The results also highlight the critical role of vulnerability in shaping spatial risk patterns, highlighting the need to integrate vulnerability into risk assessment methodologies. Ultimately, this study advocates for moving beyond single-hazard paradigms in disaster risk reduction and urban planning, and proposes a simple, adaptable framework that can be applied to assess multi-hazard risk due to the compounding nature of natural hazards.