Response of urban flood resilience to climate change: An exploration with a novel performance-based metric considering the socioeconomic impacts of damage costs

Climate change stimulates the emergence of floods and increases flood risk for communities, resulting in extensive casualties and economic loss. Thus, flood resilience has been the focus of much attention. Integrated and holistic metrics are important for an accurate urban flood resilience evaluation. However, performancebased metrics involving surface inundation do not consider the socioeconomic impacts of damage costs on the recovery ability of the urban systems. This hinders the investigation of climate change-induced effects on flood resilience. Therefore, this study proposed a performance-based resilience metric considering the negative impacts of flooding damage costs. The proposed metric was then piloted in a highly urbanized area in Osaka City, Japan to explore the responses of flood resilience to climate change. The results suggest that climate change exerts non-negligible pressure on the study area to maintain its economic characteristics during flooding. Rainfall intensity primarily affects the urban system's most unfavorable state, while the total amount and duration of rainfall mostly impact the relatively stable state following flooding. Climate change severity is positively linked to the reduction in overall flood resilience. Continued climate change will further expand the spatial coverage of flood resilience losses on a global scale. Furthermore, the negative impacts of economic losses on flood resilience are more noticeable during rainfall events with higher rainfall intensities. This study improves the comprehensiveness of performance-based flood resilience evaluations and provides a reference for the effective enhancement of urban flood resilience under climate change.