Vulnerability Distribution Model of Critical Infrastructures Based on Topological System Simulation

摘要

Urban critical infrastructures provide citizens with lifeline functions such as water, electricity and energy, etc. These interconnected infrastructure systems require reliable models for vulnerability measurement and topological controllability against usual disruptions and unusual hazards. This paper proposes a vulnerability distribution model to describe vulnerability distribution patterns in critical infrastructure system. To describe transmission of vulnerability between different infrastructure components or topological nodes, a vulnerability distribution network (VDN) is developed for simulation of negative impact on each node. The results are represented in a rasterized distribution diagrams by three metrics of vulnerability: the total number of effective topological nodes, the node's serviceability and the descent rate of coverage of infrastructural service. Then this model is applied to a case study of a local gas system and a local electric power system. Results show that a node's vulnerability and serviceability is closely related to the node's degree, especially the out-degree, while overall system's vulnerability is greatly affected by descent rate of coverage of each infrastructural service node. The model also generates probabilistic simulation graphs to show continuous vulnerability distribution in areas covered by the specified critical infrastructure systems. The graphic representation of VDN model results further helps infrastructure managers conduct route planning for transportation of hazard goods and optimize allocation of emergency resources.