Redai dili (Apr 2025)
Modeling Study on Cascading Failures of Critical Infrastructure in Urban Flooding: A Case Study of the Maozhou River Basin
Abstract
Global climate change has increased the frequency and severity of urban flooding, posing significant risks to critical infrastructure. The resulting disruption of essential services has profoundly impacted the daily lives of urban residents and, in extreme cases, endangered their safety. A systematic framework has been developed to address this, integrating flood process simulation, critical infrastructure modeling, and social vulnerability analysis. This framework elucidates the complex interdependencies among urban infrastructure systems, evaluates the impacts of flood-induced service disruptions on urban populations in the context of climate change, and assesses the resilience of various infrastructure services. The Shenzhen-Maozhou River Basin, prone to flooding, was selected as the study area. Based on the Delft3D model and using the "Mangkhut" typhoon event as a benchmark, rainfall and sea-level rise were selected as uncertainty factors to simulate and identify three future extreme flood scenarios. A network-based approach was employed to construct an infrastructure system network model that included seven types of infrastructure: substations, communication base stations, hospitals, fire stations, police stations, shelters, and water supply plants. The flood simulation results were used as inputs to the infrastructure system network model to obtain the simulation results, which were then analyzed. The results revealed the following. 1) Within the system's topological structure, the degree value of substation nodes is significantly higher than that of other facilities, making them a critical node for cascading failures triggered by floods. The power-outage areas simulated by the constructed model demonstrate a 62% concordance rate with the historical validation data, indicating a relatively high credibility level. However, due to the sensitivity and confidentiality of the data, the validation work is not yet sufficient. The types of infrastructure involved in the validation are limited, affecting the model's reliability and parameters. Therefore, in future research, it is necessary to collaborate with relevant stakeholders to obtain the relevant data, which will be used for model validation and parameter calibration, to enhance the model's reliability. 2) During the floods triggered by Typhoon Mangkhut, the cascading effect significantly increased the number of fire stations and police stations affected, which rose from 1 to 11 and from 1 to 7, respectively. Meanwhile, the disruption of communication and medical services had a more pronounced impact on the urban population, with the ratio of the population affected by service disruptions exceeding 5 (a ratio of "1" represents 140,672 people). 3) Under the backdrop of climate change, the disturbance of future extreme flood disasters on the infrastructure system network is significantly intensified. After taking into account the cascading effects, the overall number of affected infrastructure facilities is, on average, 38% higher than the baseline scenario of "Mangkhut" 4) Thanks to the relatively rational spatial layout and the flood resistance of the facilities, the power system, emergency response (covering police and fire services), and shelter services in the Maozhou River Basin have demonstrated a certain degree of stability. This study helps clarify the complex interdependencies among urban infrastructures, assess the impact of floods on the stability of service systems, and identify potential cascading effects on residents ' lives. It provides decision-making support for urban disaster prevention, mitigation planning, and emergency response strategies.
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