Research On Regional Disaster Chain Risk Based On Hazard-affected Body

With the development of society and economy, kinds of emergencies occurred frequently along with a series of secondary events, and disaster loss may be accumulated and amplified through disaster chains. Thus, focusing on disaster chain in disaster risk study is necessary for holding potential hazards comprehensively. Due to the uncertainty and difference of the type and region events occurred, disaster chain risk is up. Understanding the mechanism of regional disaster chains and study on key elements and structure of region are important premises for regional disaster chain risk assessment.Firstly, the concept of region which is composed of hazard-affected bodies and their relations was defined. Based on mechanism of emergency chain reaction, explained the role hazard-affected bodies played in the formation process of regional disaster chains. From the process, put forward that regional disaster chain risk is integrated result of hazards, regional hazard-affected bodies and regional hazard-affected body relations, and then made an explanation of each risk factor.Secondly, theoretical and statistical analysis of the role hazard-affected bodies and their relations played in emergency chain reaction was made. Classified emergency events and hazard-affected bodies, extract object disaster chains from a thousand of disaster cases using the method of event tree analysis. Then based on these disaster chains, paper performed statistical analysis on the triggering relations between events, the action relations between events and hazard-affected bodies, the hierarchies of hazard-affected bodies in disaster chains. At last, defined the types of hazard-affected body relationship, and analyzed its influential role in chain reaction.Finally, according to previous analysis about hazard-affected bodies and hazard-affected body relations, raised hazard evaluation index of hazard-affected body and grading standard from the perspective of disaster chain to conduct assessment. Combined with the analysis for the influence area of hazard-affected body, established the risk assessment model of regional disaster chain. Risk is the sum of disaster chain risk raised by each hazard-affected body in region. Then the simulation is used to analyze the change of regional disaster chain risk under the influence of different hazard-affected bodies and hazard-affected body relations.Start with region, regard hazard-affected bodies as the core, which could make regional disaster chain risk more pertinent, make use of the regional similarity and dissimilarity to do disaster risk prevention. Paper confirmed the vital role of hazard-affected bodies and hazard-affected body relations in regional disaster chain, which can provide new ideas for risk assessment of disaster chain.