暴雨洪水下中小型水库致灾因素与风险防控对策OA

Traditional single-factor statistical analysis methods can hardly fully reveal the dam breach modes caused by the combined action of multiple disaster-causing factors.To identify the major disaster-causing factors of small and medium-sized reservoirs and their typical combinations under rainstorm conditions,3562 dam breach cases in China from 1954 to the present were systematically reviewed,in which small and medium-sized reservoirs accounted for 99.94%and earth-rockfill dams for 94.33%of the total,and overtopping and engineering quality defects accounted for 51.09%and 37.20%,respectively.On this basis,51 dam breach cases of small and medium-sized reservoirs and 19 distress cases without dam breach were selected as samples.Fifteen factors were screened out from the aspects of engineering characteristics,flood control capacity,defects and hidden hazards,operation management,and emergency disposal to establish an analysis index system.A method combining descriptive statistics with the Apriori association rule algorithm was adopted to analyze the distribution characteristics of each factor and its combination relationships with the distress outcomes.The results show that overtopping breaches are mainly related to factors and their combinations such as dam type,dam height,historical period,hydrological monitoring and forecasting,and flood discharge capacity,whereas seepage-induced breaches more frequently involve engineering quality,historical period,whether reinforcement was carried out,flood discharge capacity,and human operation.Among the samples that experienced dangerous situations without dam breach,the combination of low dam height and scientific emergency disposal accounted for 47.37%,indicating that the level of emergency disposal is the key factor determining whether a dangerous situation evolves into a dam breach or remains under control.Based on the disaster-causing processes of the cases,two typical failure paths of dam breach modes,namely the overtopping type and the seepage-induced type,were constructed,and classified prevention and control measures were accordingly proposed.This study can serve as a reference for the renovation and upgrading,risk elimination,and reinforcement of aging reservoirs.