A comparative analysis on flood risk assessment and management performances between Beijing and Munich

With climate change and rapid urbanization, the prevalent flood disasters and associated risks in urban areas have become increasingly crucial global issues. Risk assessment is a basic step in flood management and mitigation, while flood management is important to achieve risk mitigation. A comprehensive assessment framework considering both pre-and post-disasters that can address flood risk is lacking. Therefore, this study developed an integrated framework by combining the assessments of flood risk and flood management performance. Taking Beijing and Munich as research objects, this study generated flood risk maps at the grid scale for the period 2000-2020 and comparatively assessed the performance of various flood management measures. The urban flood risk in Beijing showed an increasing trend and then a decreasing one from 2000 to 2020, exhibiting high spatial characteristics in the southeast and low spatial characteristics in the northwest. The flood risk in Munich showed an overall decreasing trend, with strong spatial characteristics in the center area but less so in suburban areas. The shift from low to high urbanization levels was the major factor increasing the regional flood risk. Therefore, effective flood management measures in urban areas could potentially mitigate the flood risk, and Munich had a higher flood management performance owing to its well-developed flood management systems. This study provides a new framework for flood risk assessment and resilient flood management and contributes to the development of practical measures for disaster mitigation in rapidly-developing urban areas.