Risk Analysis And Assessment Of Urban Public Safety Event Chain Based On Complex Network

With the advancement of urbanization,natural disaster emergencies have expanded their state of affairs in the form of event chains,making their impact and the scope of prevention far beyond the areas directly affected by the disaster,exerting a huge impact on urban public security and hindering Urban economic development,scientifically and objectively grasping the situation of various emergencies caused by urban natural disasters,especially the analysis of the temporal and spatial evolution laws and changing trends between the chain of events,and the risk assessment of emergencies are the solutions to urban public safety Effective means to prevent and control problems is also the basis for serving social groups and urban public safety planning and construction and emergency management.Due to the lack of an effective way of expressing and evaluating natural disaster events,there is an urgent need for a feasible way to express the complexity law and nature of the event chain effect.The research content of this paper builds a unified description model of the event chain,and by This realizes the description process of the occurrence and development of the disaster event and the risk assessment of the event.The research area of this paper is Shenzhen.Firstly,the historical disaster data of Shenzhen is collected to construct the typhoon event chain model,and then the complex network theory is used to analyze the risk of the event chain,and the key nodes in the typhoon event chain model are obtained.Carry out the importance evaluation,which reflects the characteristics of the risk system from the perspective of the event chain;and builds the corresponding model based on the comprehensive risk assessment method of the typhoon event chain of the multi-dimensional matrix,and comprehensively and quantitatively characterizes the degree of the typhoon event chain risk analysis.The main content includes merging the analysis results of the three factors of disaster-causing factor,disaster-pregnant environment and carrier in the chain of events,and quantifying the impact index of each factor,and performing it according to the corresponding weight distribution and other methods.GIS spatial visualization expression.The main research content of this paper includes the following points:(1)The basic concepts of risk assessment of complex networks and multi-dimensional matrix event chains are introduced respectively,as well as the calculation methods of related quantitative analysis.A method for risk analysis of the typhoon-storm event chain network using complex network theory,and the use of multidimensional matrix theory to determine the content,framework,process,and methods of the comprehensive risk assessment of the typhoon-storm event chain are proposed.(2)Determine 21 disaster events based on basic factors such as the characteristics of the research area in Shenzhen and typhoon natural disaster events,and use an adjacency matrix that can reflect the direct connection between the events to construct the natural disaster event typhoon as the node,and the event development connection To connect the edges of the typhoon-heavy rain event chain complex network model;use the node access degree and clustering coefficient to conduct risk analysis on the event evolution process,and determine the key nodes in the network that cause damage to Shenzhen's public safety;use the complex network's invulnerability Evaluation index,a comprehensive evaluation model of directed edges in the event chain network is proposed,which ranks the importance of the event propagation process,and then determines which secondary events need to be prevented first when performing event management.(3)The comprehensive risk assessment method of the typhoon event chain based on the multi-dimensional matrix is used to conduct a comprehensive risk assessment of the typhoon event chain model.The advantage of this method is that the disaster-causing factors,disaster-bearing environment and disaster-bearing body involved in the event chain are multi-dimensional Analyze and use the calculation method of related mathematical models to determine the index system and method for the risk assessment of the typhoon-heavy rain event chain,and analyze the risk index of 9 index factors such as heavy rain,land,river network,and population to Shenzhen.