Research Of Disaster Spread And Control In Infrastructure Networks

Interdependent infrastructures are the cornerstone of modern society. In recent years, various types of man-made or natural disasters, such as the "911" terrorist attacks and Hurricane Katrina, frequently break out and spread in infrastructures. Many authoritative agencies, such as President's Commission on Critical Infrastructure Protection (PCCIP), have suggested that the research of disaster spread and control in infrastructures should be vigorously carried out. This is not only the reality need of national security, but also has important practical application value.The dissertation, beginning with analysis of single infrastructure network, is focused on the interdependence study of infrastructures. By taking the snow disaster which broke out in infrastructures in a major city in Central China in 2008 as a study case, it establishes the interdependent infrastructure network model and analyses the spread of deliberate attack and natural disaster in infrastructures. Several kinds of disaster control strategies are proposed based upon load adjustment and rescue resource allocation, of which the spread impact and control effect are discussed based upon simulations. The main contents are summarized as follows:(1) By taking the interdependent infrastructure network consisting of water supply network and power supply network of a major city in Central China as a study case, the dissertation analyzes the problem of disaster spread and control in infrastructures through both structure and function. It is found that the power supply network has high clustering coefficient and short average path length, and the network exhibits a very high degree of robustness against random attack but a low robustness against deliberate attack. It is also found that the water supply network has low clustering coefficient and short average path length, and the network exhibits a low degree of robustness against random attack and deliberate attack. After that, the function model of power supply network of the city is established and simulated for three kinds of disaster control strategies for three kinds of disasters. The simulation result shows that the disaster diffusion effect is of most severe degree if the attack on the big load node is of high priority, and it is most effective for the disaster control to prioritize increasing the capacity of the node with heavy load. Furthermore, based on the node load, the dissertation proposes a node repair strategy and validates it by simulation.(2) The dissertation proposes a model to study interdependent infrastructure networks according to the operation characteristics of single infrastructure and the interdependence among infrastructures. Compared with related researches, such as Agent, Input-Output, System Dynamics model, this model is able to analyze the spread impact of disaster better according to structure and operation characteristics of infrastructures. In the follow-up study, the effectiveness of the model is validated by applying it to analyze the spread and control problem for the impact of deliberate attack and natural disaster upon interdependent infrastructure network.(3) It is pointed out in this dissertation that it is crucial to locate the key node of the infrastructure network for dealing with the deliberate attack on it. Based on this assumption, a method of determining important nodes in infrastructure network based on infrastructure loss function is proposed. It is found that the connection established among infrastructure networks will both amplify the disaster spread impact, and alter the order of important nodes within any infrastructure network. To this end, the dissertation proposes a method to search the important nodes based on degree of node and interdependency of network. The simulation shows that it can effectively narrow the search scope. Finally, a resource allocation strategy for controlling the node attack risk is proposed, and its effectiveness is also analyzed.(4) The dissertation proposes a method to study the spread and control problems of natural disasters in interdependent infrastructures, and the method is validated by applying it to analyze the snow disaster which broke out in infrastructures of a major city in Central China in 2008.Firstly, by simulating the spread of snow disaster in interdependent infrastructures, it shows that the interdependent spread among infrastructure networks brings greater losses for infrastructure network. Secondly, four kinds of load adjustment strategies are simulated for infrastructure network when disaster breaks out for the sake of infrastructure loss and satisfaction of service demand. The simulation result shows that the strategy which aims at minimizing the loss of single infrastructure is the worst, and the strategy which prioritizes the interdependency of infrastructures is the best. Finally, the dissertation proposes three kinds of rescue resource allocation strategies to prevent disaster from spreading, and analyzes the effectiveness of these strategies through simulations. The simulation result shows that the strategy which prioritizes interdependent nodes yields the best performance.