在森林火灾频发、输电线路密集的区域, 架空线路失效可能引发森林火灾, 森林火灾的蔓延也会影响周边架空线路的安全稳定运行。目前, 架空线路失效与森林火灾的次生和衍生事故演化机理尚不明确, 导致相应风险管控措施可能存在针对性不足的问题。因此, 该文基于复杂网络理论构建架空线路失效及森林火灾次生和衍生事故灾害链网络, 探究“森林火灾”和“架空线路失效”互相诱发对灾害链形成机制的影响。一方面, 通过计算节点中心度、接近中心度等指标, 多角度评估各灾害节点在灾害链网络中的作用及影响程度, 进而确定架空线路失效及森林火灾次生和衍生事故灾害链的关键节点; 另一方面, 以灾害链各演化路径的传递概率为评价准则, 利用Jaccard指数提取关键传播路径。在此基础上, 结合断链减灾理论明确如何有效地阻止次生灾害的发生, 为实际森林火灾防控及森林电网运维提供决策支持。

Objective: Forest fires can be triggered by the failure of overhead power lines, especially in forests that are prone to wildfires and have dense power transmission networks. The spread of such fires can, in turn, endanger the safety and stability of nearby power infrastructure. Understanding the evolution of forest fires and the mechanisms behind secondary and derivative accidents is essential for implementing risk control at key nodes within the disaster chain. This is crucial in reducing the likelihood of disaster occurrence and the severity of its consequences. However, research on secondary and derivative disaster chains related to forest fires remains limited, and no existing studies have addressed the coupling induction between forest fires and overhead line failures. This gap may lead to risk control measures that are inadequately targeted. Methods: In this study, a secondary and derivative disaster chain network of overhead line failures and forest fires is built based on complex network theory, and the effect of the coupling induction of forest fires and overhead line failures on the formation mechanism of the disaster chain is investigated. First, indicators such as degree centrality and closeness centrality are calculated to evaluate the role and influence degree of each disaster node in the disaster chain network from multiple perspectives. Subsequently, the key nodes in the failure and secondary and derivative disaster chains between overhead lines and forest fires are determined. Second, the transmission probability of each evolution path in the disaster chain is used as the assessment criterion, and the Jaccard index is employed to identify the key evolution paths. Results: First, 92 related accident cases are analyzed, and experts are consulted to determine the inducing relationships among various disaster nodes. Based on this, a disaster chain evolution model is constructed to investigate the failure and secondary and derivative accident chains of the overhead lines and forest fires. This model has 21 disaster nodes, 46 edges, and 60 disaster evolution paths. Four indicators are calculated: degree centrality, closeness centrality, betweenness centrality, and disaster node hub count. The top five disaster nodes are forest fires, casualties, overhead line failure, forest resource destruction, and toxic gas leakage. The transmission probabilities of different disaster evolution paths are calculated based on the frequency of the disaster chain nodes in statistics and the Jaccard index. To confirm the validity of the model and its conclusions, a sensitivity analysis is conducted at the node of overhead line failures, which verifies the relevance of risk management for overhead lines in reducing the risk of the disaster chain. Conclusions: Based on theory of chain-cutting disaster mitigation, how to cut off the evolution paths of the disaster chain or the control key disaster nodes and how to prevent the occurrence of secondary and derivative accidents are clarified in this paper to provide decision support for the actual prevention and control of forest fires and the operation and maintenance of forest power grids.