This research develops a hybrid approach that integrates disaster chains and complex networks to model and assess vulnerability in urban transit systems. A weighted complex network is established by combining various disaster chains and their frequencies in the operation of the urban transit system, where disaster events and their transmission paths in chains are considered as nodes and edges in the disaster network, respectively. Several measures are proposed to quantify the vulnerability magnitude of the disaster nodes, edges, and network from both micro-level and macro-level perspectives. A weighted complex network consisting of 31 disaster nodes and 73 edges is constructed to model the disaster transmission in the operation of the metro system. Results show that (1) The steward misoperation (Node 15), the unqualified maintenance (Node 17), and the edge E38 (from Node 17 to Node 23) are identified as the most vulnerable nodes and edge, which should be paid more attention for disaster risk reduction; (2) The network efficiency is calculated to be 0.1244, acting as an anchor for improving system resilience against disasters; (3) The proposed edge vulnerability measure proves to be more effective in discovering more vulnerable edges than the traditional edge measure. Both node and edge attack analysis are performed to discuss the robustness of the developed complex network. It is found that all the intentional attack strategies display better performance for reducing network efficiency than random attack strategies, and global attack strategies are more efficient in both node and edge attack analysis than local attack strategies. This indicates that the developed approach is necessarily effective to identify the vulnerability of disaster events and links in the urban transit system, enabling to discover the best strategy for improving the resilience of the transit system against disasters.

这项研究开发了一种混合方法，该方法将灾难链和复杂网络集成在一起，以对城市交通系统中的脆弱性进行建模和评估。通过组合各种灾害链及其在城市公交系统运行中的频率来建立加权复杂网络，其中灾害事件及其链中的传播路径分别被视为灾害网络中的节点和边缘。提出了几种措施来从微观和宏观两个角度量化灾难节点，边缘和网络的脆弱性程度。构建了由31个灾难节点和73个边缘组成的加权复杂网络，以对地铁系统运行中的灾难传输进行建模。结果表明：（1）管家误操作（节点15），不合格维护（节点17），边缘E38（从节点17到节点23）被确定为最易受攻击的节点和边缘，在降低灾难风险方面应引起更多关注；（2）网络效率经计算为0.1244，可作为提高系统抗灾能力的基础；（3）与传统的边缘措施相比，所提出的边缘漏洞措施被证明在发现更多脆弱边缘方面更为有效。进行节点和边缘攻击分析以讨论开发的复杂网络的鲁棒性。发现所有故意攻击策略在降低网络效率方面都表现出比随机攻击策略更好的性能，而全局攻击策略在节点和边缘攻击分析方面都比本地攻击策略更有效。