Flood Resilience Dynamics and Influencing Factors in Beibu Gulf Urban Agglomeration Across Spatial and Temporal Scales

Flood resilience is becoming increasingly crucial in the background of global climate change and urbanization, especially in regions susceptible to frequent and compound flooding. This study develops a long-term, cross-scale dynamic systems-based framework based on the "Robustness-Resistance-Recovery" (3Rs) to evaluate the spatiotemporal evolution of flood resilience from 2000 to 2020 in the Beibu Gulf Urban Agglomeration. This framework integrates social, economic, and ecological dimensions to analyze the dynamics of flood resilience in the Beibu Gulf Urban Agglomeration that is confronting complex challenges due to rapid development and flooding. The optimal parameters-based geographical detector model, which accounts for spatial heterogeneity and temporal dynamics, was employed to identify key influencing factors and mechanisms shaping resilience. The findings reveal spatial disparities in flood resilience: pre-flood robustness is higher in inland areas but lower in coastal areas; during-flood resistance is associated with greater urban development; and post-flood recovery is stronger in city centers and mountainous areas but weaker in low-lying inland and coastal areas. Over the past two decades, significant improvements in flood resilience have been driven by advancements in infrastructure and healthcare, although their impact is relatively limited compared to the contributions of economic. Notably, ecological factors have emerged as critical drivers in recent years, indicating a shift toward sustainable adaptation strategies. These findings are expected to serve as a practical reference for urban flood risk management and resilience planning, adaptable to other regions facing comparable challenges.