Abstract: BackgroundTo scientifically assess the operational risk level of check dams on the Loess Plateau in Inner Mongolia and provide theoretical support for their risk early warning and engineering management。MethodsA multi-dimensional and hierarchical risk evaluation index system was first constructed in this study by identifying key influencing indicators using the Decision-Making Trial and Evaluation Laboratory(DEMATEL)method.Secondly,the weights of the indicators were determined separately via the Fuzzy Analytic Hierarchy Process (FAHP) and the Order Relation Analysis(G1)method,and game theory was applied for weight fusion to ensure the rationality of weight allocation.Finally,a quantitative assessment was realized based on the cloud model:specifically,the cloud characteristic values of the indicators were calculated using the inverse cloud generator,the comprehensive evaluation cloud was generated by combining the indicator weights with the forward cloud generator,and cloud similarity was introduced to quantify the membership degree of the comprehensive evaluation cloud to different evaluation grades.ResultsAn empirical analysis was conducted with the Housha Check Dam in Inner Mongolia as the research object,and the results showed that the operational risk evaluation grade of this check dam was "basically safe",with a normalized membership degree of 70.5%.This result was highly consistent with those obtained by the fuzzy comprehensive evaluation method and the set pair analysis method,and it also matched the actual engineering situation.ConclusionsThe study indicates that the constructed evaluation system and method are effective and reasonable,which can accurately reflect the operational safety and risk status of check dams and provide reliable references for the risk management and control of check dams in similar regions.