Mapping world’s coastal population facing water-related risks

This document develops a spatial multi-stressor, multi-risk framework for assessing water-related risks to people living within 100 km of the world’s coastlines, aligned with the UN Sendai Framework and the IPCC coupled systems approach. The study analyses six major water stressors, namely variability in water supplies, overuse, floods, droughts, eutrophication and inadequate drinking water, by combining stressors with population exposure and vulnerability. It maps global hotspots and identifies characteristic geographic patterns, revealing that risk is strongly concentrated in densely populated coastal areas and around the Tropic of Cancer. The most significant hotspots include the Chinese coast, the Bay of Bengal, Gujarat and Java. 

This document finds that eutrophication affects the largest number of people in the coastal zone, followed by inadequate drinking water, overuse, droughts, variability and floods. China, India and Indonesia account for a disproportionately large share of the global coastal population facing water-related risks, while several African countries have the highest proportions of their populations at risk. The authors emphasize the importance of high-resolution spatial analysis of vulnerability, exposure and water-related stressors to support policy design and shared responsibility for managing stress-prone areas. They recommend expanding future assessments to include additional environmental and health risks, compounding risks, temporal dynamics, climate change projections and more consistent probabilistic risk assessment approaches.