Flood disaster chain deduction based on cascading failures in urban critical infrastructure

With the acceleration of global climate change and urbanization, cities are increasingly vulnerable to extreme rainfall and flooding disasters. Urban infrastructure, which is interconnected physically, geographically, and informationally, serves as a carrier for the propagation of disasters, amplifying their effects and exacerbating the overall system's vulnerability. This paper proposes a novel method for analyzing urban flood disaster chains, using cascading failures within critical urban infrastructure networks as a basis. The method first constructs extreme rainfall flood disaster scenarios for urban areas through numerical simulation, considering rainfall and hydrological conditions. Next, a network model is developed that encompasses key urban infrastructures, including electricity, transportation, and communication systems. The coupling mechanism of these three critical infrastructures is defined, considering their geographical and physical connections. By analyzing the failure modes and propagation pathways of these infrastructures under extreme rainfall scenarios, the method explains the nonlinear spatiotemporal evolution of flood disaster chains, from localized failures ("points") to broader network-wide disruptions ("lines"), and ultimately to extensive systemic failures ("planes"). Furthermore, the impact of protecting key nodes within the infrastructure on the spatiotemporal evolution of disaster chains is analyzed. This analysis demonstrates how safeguarding critical points can disrupt the disaster chain and mitigate the impacts of flooding, offering new perspectives and analytical tools for urban flood disaster management and emergency response strategies. The findings are significant for understanding the interdependencies within urban infrastructure and enhancing the disaster resilience of urban systems.