Research On Tailings Dam Risk Assessment Based On Possibility Of Set-valued Mapping

Due to the frequent tailings dam break accident recently, serious influence have beencaused to the nation, people’s life and property as well as environmental safety, which makesthe risk assessment technology with early warning ability development fast. However, themapping method in the existing risk assessment models can not effectively reflect themapping complex and changeable between instability index information and risk levelinformation, also does not consider the impact of non-rational of decision-makers to theassessment result, which causing the problem that the evaluation effect is poor, or evenmiscalculation.Possibility theory has its own distinct advantages in the establishment of complexmappings between heterogeneous information; Prospect theory ca n describe the psychologyof non fully rational in decision makers. Therefore,in this paper I take the upstream tailingsdam as objects and apply the possibility theory as well as prospect theory to the riskassessment model, to solve the problems of tailings dam risk evaluation effect poor,or evenmiscalculation. The main results are as follows:(1) Analyzing the characteristics of instability index information about the tailings dam,then using the sample-based possibility distribution method to characterize the instabilityindex information; According to the problem that the level of risk information cannotdynamic change along with the state of the dam caused by the existing risk classificationstandards, analyzing tailings dam change mechanism,then comb ining its inherent frequency todivide risk level.(2) Because of the complex and changeable of mapping between instability indexinformation and risk level information,and the existing mapping method is difficult to dealwith the complex mapping between heterogeneous information, so I used the possibility ofset-valued mapping to establish the map between instability index and risk level.(3) According to decision makers have the psychology of draw on the advantages and avoid disadvantages in the tailings dam risk assessment, I used the prospect theory to buildrisk assessment model, and introduced the correlation between instability indexes to theweight determination,which make the evaluation model is more accord with the actualsituation.(4) Through the example to verify the rationality and validity of the method. The resultsshows that: Risk assessment model based on the prospect theory can effectively avoidindividual decision making factors to judge effects, which make the result of the riskassessment more reasonable and improved the accuracy of risk assessment results.