The Appraisal Of Small Reservoirs’ Safety Status In Kaifu District,Changsha City Based On GAHP And Fuzzy Comprehensive Evaluation Method

Due to the limitation of the construction technology,professional equipment and operation management level at that time,some existing reservoirs in China,which were built in the 1950s and 1970s,have experienced disease and aging,and endanger the lives and property of the people.Evaluating the safety issues of reservoirs with scientific and objective methods,and coming up with workable measures to preserve and reinforce different risk levels of reservoirs,are the priority among priorities to propel the reservoirs management now and in the future.Aiming at the factors that lead to the risk of reservoirs,this article studied crash patterns of small reservoirs and summarized the main manifestations of reservoir disease,then analyzed the causes of reservoir disease and established a set of risk factors that affect reservoir safety.It is concluded that the existing dangerous reservoirs in this area mainly have five safety hazards.Finally constructed the safety evaluation index system of small reservoirs in Kaifu district,which included a first-level hierarchical indicator(objective layer)—small reservoir safety in Kaifu District,and 5 second-level hierarchical indicators(criterion layers),including structural safety,engineering quality safety,flood control safety,operation management safety,and ecological safety,and 15 third-level hierarchical indicators(measures layers),involving impermeability,deformation stability,flood control standards,biodiversity and so on.Based on the gray analytic hierarchy process,this article obtained indicators for each level given by experts and finally determine the weight value of each layer index relative to the target layer,combined with the principles of determining evaluation indicators and the characteristics of the reservoir structure itself.The impermeability in structural safety is the first,and the ecological water demand satisfaction degree in the ecological security is the 15th in the weight ranking.This article considered the fuzzy theory into the research of comprehensive evaluation of reservoir status,and studied the basic steps of multi-level fuzzy comprehensive evaluation,the choice of membership function and the processing method of fuzzy comprehensive evaluation index,and then using the fuzzy comprehensive evaluation method to comprehensively evaluate the safety status of the reservoir,and evaluate the safety status of the reservoir with five levels.Taking the small reservoirs in Kaifu District as the research object,including Shigutang,Yupotang and Hanposhan Reservoirs in Kaifu District,it evaluates the safety degree with method above.The safety subordination degree of Shigutang reservoir is unhealthy,while the degrees of Yupotang reservoir and Hanposhan reservoir are incomplete healthy and unhealthy respectively.And at the same time,a solution based on the cause of the disease is given,and practical guidance for the safe operation and management of reservoirs in the jurisdiction is given based on the calculation results.The feasibility of this analysis method is verified,which can be used as a reference for similar projects,and has good application prospect and value.