A framework for urban flood resilience assessment: Integrating multidimensional indicators and dynamic adaptation strategies.

Against the backdrop of global climate change and accelerated urbanization, the risk of urban flooding continues to rise. To address the flood risk prevention needs of megacities, this study takes four Chinese municipalities (Beijing, Tianjin, Shanghai, and Chongqing) as typical cases. It constructs a PSR-GRA-based urban flood resilience assessment framework by quantifying key indicators via the Pressure-State-Response (PSR) framework and scientifically calibrating parameters for pressure, state, and response dimensions using Grey Relational Analysis (GRA). The framework integrates structured and quantitative methodologies, covering the three stages of pressure, state, and response in the evolution of urban flood resilience, evaluating cities' capabilities to withstand flood impacts from extreme rainfall and rapidly restore normal urban operations. Using official data from the four cities spanning 2013-2023, comparison of the framework's assessment values with actual disaster scenarios reveals significant correlations between UFRI (Urban Flood Resilience Index) results and flood frequency/severity, confirming the PSR-GRA model's reliability and effectiveness. Assessment results show the four municipalities' UFRI all rose positively from 2013 to 2023, with distinct trajectories due to differences in geography, climate, and urban development models. To enhance assessment dynamics and practical guidance, adaptive management is integrated into the PSR-GRA model, establishing a "monitoring-assessment-response-feedback" closed-loop system for precise regulation of resilience improvement strategies. This validated framework provides a comprehensive, replicable approach for urban flood resilience evaluation and planning-particularly suitable for megacities' flood-prone areas, offering references for mitigating flood risks and strengthening urban planning to enhance long-term adaptability.