Coastal urban flood risk under compound hazards: A systematic review and a resilience framework for disaster risk reduction

Coastal cities are increasingly exposed to compound flooding driven by the interaction of sea-level rise, storm surge, extreme precipitation, and urbanization under climate change. Although both urban flood resilience (UFR) and coastal resilience frameworks have advanced disaster risk reduction, they remain insufficiently integrated for land-sea-subsurface interactions in coastal cities. This gap limits the effectiveness of resilience-based planning and may lead to underestimation of compound coastal flood risks. This study conducts a systematic review of the evolution of urban flood resilience research and synthesizes the drivers, mechanisms, and distinctive characteristics of coastal urban flooding. Based on an integrated analysis of climate forcing, marine dynamics, urban development, and subsurface processes, we develop a Coastal Urban Flood Resilience (CUFR) framework that reframes resilience from a general concept to a coastal-specific risk perspective. The framework emphasizes dynamic adaptation over rigid resistance and explicitly links engineering, ecological, and social dimensions to the processes that govern compound flooding and post-event recovery. To illustrate the practical relevance of CUFR for disaster risk reduction, representative international cases from New York, Rotterdam, and Shanghai are comparatively analyzed. The synthesis demonstrates how coordinated measures across multiple dimensions can reduce functional disruption, mitigate cascading impacts, and accelerate recovery under compound flood scenarios. By clarifying the mechanisms and governance implications of coastal flood resilience, this study provides a structured lens to support risk-informed decision-making, policy design, and climate adaptation strategies for coastal cities facing increasing flood hazards.