Comprehensive Evaluation Of Dam Safety Based On Standard Method And Analytic Hierarchy Process

Since New China,China has built many reservoirs.These reservoirs have made great contributions to flood control,water supply,irrigation and power generation,aquaculture,ecology,shipping and tourism,and have also created considerable economic and social benefits,playing an indispensable role in China's flood control safety system.From 2010 to 2020,China carried out the first nationwide water conservancy census.The water conservancy census shows that China has 98,002 reservoirs,mostly built in the 1920 s to 1970 s,with a total capacity of 932.312 billion cubic meters.China has become the country with the largest total reservoir capacity,the largest beneficiary population and the largest protected population in the world.Since some reservoirs in our country started to be built in the 1920 s with a long operation time,problems of large and small size appeared one after another,and the safety evaluation standard of reservoirs was gradually improving,which made many reservoirs in our country have to carry out all-round safety evaluation.The safety problems of these reservoirs and dams not only directly affect the full play of engineering benefits,but also threaten the life and property safety of downstream people,which is a major event related to the national economy and people's livelihood.Therefore,more and more attention has been paid to the safety of reservoir dams.In-depth analysis of testing data and correct evaluation of dam safety have become an important work in dam industry at home and abroad.By studying the safety evaluation of existing reservoirs and dams,it can not only guide the flood control and dam safety prevention of existing reservoirs,but also guide the safety design research of future reservoirs and dams.Therefore,it is of great practical significance to study the safety evaluation of existing reservoirs and dams.The traditional comprehensive safety evaluation of reservoirs is a qualitative method,which takes dam engineering safety as the center to comprehensively evaluate the safety of reservoirs and dams.However,the evaluation of normative method is mainly based on qualitative judgment,which is easy to cause disputes and differences on decision-making.The importance of each part is not prominent and the weight is not clear when making decisions.Only qualitative methods are used to divide reservoir dams into three categories,and it is impossible to compare the anti-risk capabilities of different reservoirs belonging to the same category.Analytic Hierarchy Process(AHP)has established a quantitative evaluation and analysis model for reservoir safety evaluation.Compared with the current regulations,the evaluation model can draw quantitative conclusions and reflect the severity of the reservoir's risks,thus making more reasonable decisions on the reservoir's risk removal and reinforcement projects.Analytic Hierarchy Process focuses on sorting and determining the weight of each evaluation index.According to the scores obtained from reservoirs,the severity of disease risks of reservoirs of the same grade can be compared.The lower the total score of the reservoir,the more serious the risk problem is and the more urgent the need for risk removal and reinforcement is.Moreover,due to the evaluation and argumentation of experts and professors,the AHP model has constructed a reasonable and objective judgment matrix and evaluation criteria,making the model more reliable and practical.In this paper,the standard method and analytic hierarchy process are used to evaluate the dam of Dashan Reservoir comprehensively.The evaluation results of the two methods are equivalent,and the evaluation results of the dam of Dashan Reservoir before the danger removal and reinforcement in 1998 and the current dam of Dashan Reservoir in 2017 are respectively obtained as three types of dams and unsafe dams.At the same time,the analytic hierarchy process concluded that although the reservoirs were unsafe dams in both periods,the total score of the reservoirs before risk removal and reinforcement in 1998 was lower than that in 2017,indicating that the risk level of the reservoirs before risk removal and reinforcement in 1998 was much more serious than that in 2017.When the flood season comes,it is more likely that the reservoir will overflow or break before danger removal and reinforcement in 1998.Analytic Hierarchy Process(AHP)is feasible for reservoir dam safety evaluation,and is a new method worth studying for reservoir dam comprehensive safety evaluation.