基于Petri网的VOCs跨区域流动动态风险评估方法

为了评价污染天气下由于VOCs(volatile organic compounds)跨区域流动产生的区域间的相互影响作用的大小，找出对受污染区域影响较大的路径，结合Petri网模型提出了VOCs跨区域流动动态风险评估方法。利用HYSPLIT模型确定多个潜在污染源与受污染区域的VOCs迁移路径，运用Petri网去描述各个迁移路径之间的关系；将动态风险大小的计算融入到函数Petri网的运行中，定量评估潜在污染源到受污染区域的各条路径的风险程度；案例分析得出污染天气下周边区域对于西安的动态风险评估结果以及各污染路径的潜在风险指数。研究表明，在重污染天气下各个污染源城市对西安的影响程度大小由高到低依次为宝鸡>汉中>西宁>兰州。该方法为评估VOCs跨区域流动过程中潜在污染源的风险程度提供了依据。

Dynamic Risk Assessment of VOCs Cross Regional Flow Based on Petri Nets

In order to evaluate the interaction between regions due to the cross regional flow of VOCs(volatile organic compounds) under polluted weather, a dynamic risk assessment method of cross regional flow of VOCs is proposed by using Petri net modeling method. The migration paths of VOCs between multiple potential pollution sources and contaminated areas are determined by HYSPLIT model, and the relationship between each migration path is described by Petri net; the dynamic risk assessment method is defined, and the calculation of dynamic risk is integrated into the operation of functional Petri net; through case analysis, the dynamic risk assessment results of surrounding areas for Xi'an under polluted weather and the potential risk index of each pollution path are obtained. The research shows that under heavy pollution weather, the influence degree of each pollution source city on Xi'an is Baoji > Hanzhong > Xining > Lanzhou from high to low. This method provides a basis for evaluating the risk degree of potential pollution sources in the cross regional flow of VOCs.