A regional Natech risk assessment based on a Natech-prone facility network for dependent events

Because of the recent frequency of climatic hazards and extreme weather events, disasters caused by natural hazards are attracting increased attention from the governments, communities, and the public. Synergistic effects between natural and technological hazards have a significant role in risk assessment. To address these effects, a Natech risk assessment model based on a natural-technological-prone (Natech-prone) facility network is developed to clarify specific scenarios and assess Natech risk. A weighted and directed graph is employed to map out the industrial facilities and other necessary information emerging from the display. It is assumed that the final risk triggered by a natural event is the result of disasters caused by Natech-prone facilities. The decision weights of Natech-prone facilities are heavily dependent on the recognition of the interacting components. A subjective probability is applied to the expected risk utility function to overcome the disadvantage of objective probability, which fails to address the uncertainty found in irrational human factors. Fuzzy measures are used to describe the positive and negative synergistic effects caused by the interaction between Natech-prone facilities. In addition, a Choquet integral is incorporated into the method to deduce the positive and negative synergistic effects in risk assessment. A numerical example is given to illustrate the model, and comparisons and analyses are provided. This paper conceptualizes a specific scenario of a Natech accident. The use of an expected risk utility function for dependent disaster events is a new idea in the field of Natech risk assessment.