岩桑树水电站库区滑坡发育的影响因素及危险性评价

Analysis of Influencing Factors and Risk Assessment of Landslide Development in Reservoir Area of Yansangshu Hydropower Station

为定量评价岩桑树水电站库区滑坡影响因素的影响程度及危险性,根据其环境条件,确定滑坡发育的影响因素,采用数量化理论Ⅲ分析各因素的影响程度,并判断滑坡所处的危险性。分析结果表明,库区滑坡发育的主导因素为地层岩性、坡体到断层的距离和斜坡高度,且以地层岩性的影响程度最大;主要影响因素为坡体风化程度、滑坡体积和正常蓄水后的坡体浸没比;一般影响因素为坡面倾向、植被覆盖率和斜坡坡度。滑坡发育影响因素间的耦合强度多以中、强为主,说明一般影响因素对滑坡的发育也存在较大影响。同时,库区滑坡的危险性多为中或低,但随库区水位的周期性升降,滑坡的危险性将进一步增加,需加强监测或治理。研究成果为库区滑坡灾害研究提供了新思路。

In order to achieve quantitative evaluation of landslide influencing factors and risk factors, according to its environmental conditions, influencing factors of landslide development were determined by taking the reservoir area of Yansangshu Hydropower Station as an example. The influence degree of each factor was analyzed by quantitative theory III, and the hazard of landslide was judged. The case analysis shows that the dominant factors of landslide development are the, distance between slope and faults, and slope height, and stratigraphic lithology has maximum influence degree. The main influencing factors are the slope weathering degree, landslide voiume and slope immersion ratio after normal storage. The general influencing factors are slope inclination, vegetation coverage rate and slope gradient. The coupling strength between the influencing factors of landslide development is mostly medium and strong, which indicates that the general influencing factors also have great influence on the development of landslides. At the same time, the risk of land- slides is mostly moderate or low, but with the periodic rise and fall of the water level in the reservoir area, the risk of landslides will further increase, and we need to strengthen monitoring or control. The study provides a new way of think- ing for the study of the landslide disaster in the reservoir area.