基于随机Petri网的震后次生灾害演化模型研究

针对震后次生灾害的演化问题,本文采用多案例分析方法提取地震及其次生灾害事件的属性,从属性层次按照“事件类型、关键属性、从属属性、环境属性和危害评估属性”对其进行结构化描述,分析震后次生灾害事件的属性特征,绘出了震后次生灾害演化Petri网模型。在此基础上,以渐变型次生灾害事件——震后瘟疫为例,根据随机Petri网与马尔科夫链的同构关系,构建了震后瘟疫事件演化系统随机Petri网模型。最后,通过马尔科夫链及相关数学方法对震后瘟疫事件演化系统进行了评估,分析其中的均衡状态及其变动规律,验证了模型的有效性,为应对地震次生灾害事件提供科学的应急决策支持。

Modeling Evolution of Seismic Secondary Disasters with Stochastic Petri Nets

To solve the evolution problem of seismic secondary disasters, this paper extracts seismic secondary disaster attributes by the approach of multi-case study to describe seismic secondary disaster structurally from the event type, the key attributes, the secondary attributes, the environment attributes and the hazard assessment attributes, and then analyzes the properties of seismic secondary disasters and builds up the evolution Petri net model. On the basis of the evolution process, the paper applies the Stochastic Petri Nets(SPN)to model the evolution system of graded seismic secondary disasters,for example plague, and establishes the corresponding Markov chain based on isomorphic relation between SPN and Markov chain. Finally, we study the equilibrium state and fluctuation pattern of the system for evaluating and improving the system with Markov chain and corresponding mathematics method, and the simulation results show the effectiveness of the model, which providesa decision-making support for responding to post-earthquake disasters.