Responses of Urban Flood Resilience to Climate Change and Its Multi-Level Enhancement Pathway

Driven by climate change, extreme events such as floods are becoming increasingly frequent globally. To address the growing and dynamic flood risks and foster the development of resilient cities, the concept of urban flood resilience has been increasingly applied to flood prevention. Investigating multi-scale responses of urban flood resilience to climate change can help policymakers develop multi-level enhancement pathways and concrete measures to enhance flood resilience, providing guidance for urban flood risk management. However, research in this field remains insufficient. Therefore, taking the Pearl River Delta (PRD) as the target area, this study applied the pressure–state–response (PSR) model and the extension catastrophe progression method to assess urban flood resilience in 2019 and 2070 under SSP1-2.6. From the perspectives of the city, economic circle, and urban agglomeration, the impacts of climate change on multi-scale urban flood resilience and multi-level enhancement pathways for flood resilience of the PRD were investigated. Results show that its response of flood resilience to climate change is most evident in Zhuhai and least evident in Shenzhen. Climate change exerts its strongest impacts on the flood resilience of the Shenzhen–Dongguan–Huizhou (SDH) economic circle and the weakest on the Guangzhou–Foshan–Zhaoqing economic circle. Across all scales, climate change impedes the maintenance of flood resilience in the PRD, even under a low-emission sustainable development scenario. This impact is more pronounced in highly urbanized areas than in less urbanized ones. Consequently, the PRD should establish a “top-down” multi-level approach of “highly urbanized areas–the SDH economic circle–Dongguan” for flood resilience enhancement. Strengthening the flood resilience of Dongguan is of significant importance for achieving the overall enhancement in the PRD under climate change.