Flood risk under sea-level rise and lessons on adaptation policies in coastal urban management: A case study in Hai Phong City, Vietnam

Climate change and sea-level rise are increasing flood risks in coastal urban areas, including those in Vietnam. Hai Phong city, one of the most important coastal urban areas in Vietnam, has been suffering significant impacts from frequent flooding caused by rising sea levels and rapid urbanization. This study examines the level of flood risk and identifies gaps in Hai Phong’s adaptive capacity by analyzing empirical data from two sea level monitoring stations (Hon Dau and Bach Long Vi, 2014–2023), vulnerability indices (VI), flood risk indices (FRI), and institutional SWOT analysis. The findings indicate a high level of vulnerability (VI = 3.61/5) and a considerable flood risk (FRI = 0.53), particularly in coastal areas, inner-city zones, and peri-urban transition regions. Simultaneously, the study also reveals substantial limitations in local adaptive capacity, particularly regarding institutions, planning, infrastructure, and resource mobilization mechanisms. Bearing this in mind, the study draws on successful adaptation models from Japan, Singapore, Indonesia, and Thailand and highlights the effectiveness of integrated policies combining structural and non-structural measures, community participation, and intersectoral coordination. These lessons may support Hai Phong in developing a flexible, spatially and temporally adaptive action road map that integrates risk management into urban planning and governance, thereby enhancing resilience and promoting sustainable development in the face of escalating climate change impacts.