Attributing effects of classified infrastructure management on mitigating urban flood risks: A case study in Beijing, China

Abstract

Improving infrastructure construction with nature-based solutions is a feasible strategy to mitigate flood risks and enhance urban resilience. This study fitted the flood risk function of Beijing based on extreme precipitation indices to analyze the probability of flood hazards and its economic losses. Then primary drivers on flood risks and its spatial relationship were identified, especially the effects of blue, green, and grey infrastructure. Results showed that flood risks of Beijing decrease from the northwest to southeast, while economic losses decrease from the southeast to the surrounding areas. Natural topography especially slope is the major driver of spatial heterogeneity in flood risks at the grid scale (q statistic=0.101), while socio-economic development especially economic intensity are the major drivers at the community scale (q statistic=0.194). Additionally, the attributing effects of classified infrastructure on flood risks are ranked as: green infrastructure (βmin=-0.28) > grey infrastructure (βmax=0.13) > blue infrastructure (βmin=-0.2). It indicates that green infrastructure plays a more effective role in mitigating flood risks in most urban areas of Beijing rather than blue infrastructure, while grey infrastructure aggravates flood risks, especially in the northeastern suburbs. This study provides a reference for decision making on infrastructure construction and flood management in rapid-urbanization cities.