Risk Analysis of Urban Drainage System Siltation Based on Complex Networks

The performance of urban drainage systems can be significantly compromised by siltation in pipeline networks. This study focuses on the drainage network of central Zhengzhou, analyzing operational risks under current siltation conditions. Using complex network theory, the study examines the structural characteristics and propagation mechanisms of the siltation propagation chain, quantifying node risks through indicators such as pipeline risk factors and degree centrality. Edge vulnerability is incorporated to evaluate the risk values of siltation propagation paths. The study’s findings indicate the following: (1) Despite a relatively low overall siltation risk, regular pipeline inspection and maintenance is necessary. (2) A total of 22 critical nodes, primarily located in main pipelines or confluence manholes, exhibit high risk and require priority attention. (3) Siltation propagation shows significant chain characteristics, with main pipeline and junction node failures potentially leading to systemic crises. In the central Zhengzhou stormwater network presented in this paper, high-risk factors are concentrated in a southern downstream outlet caused by an edge identified as critical that propagates siltation risks to the downstream nodes, forming a long path with elevated risk levels. This study provides crucial insights into the risk management and prevention of sedimentation and blockages in urban drainage networks, not only offering important technical references and a solid scientific basis for pipeline maintenance and network upgrades—thereby contributing to drainage system planning and the enhancement of urban flood protection capabilities—but also serving as a valuable technical reference for improving the overall resilience and operational efficiency of drainage systems.