关键词: 山洪灾害, 风险评估, 风险区划, GIS技术, 易损性指标

Abstract:

After impoundment of the Three Gorges reservoir, numerous landslides relevant to water have the signs of deformation. Deformation of most landslides rapidly increases, especially in the process of decline of reservoir water level. Shuping landslide, about 47 km from the dam site of Three Gorges, belongs to a kind of giant ancient accumulation body. Monitoring results for several years showed that Shuping landslide strongly deformed when reservoir water level dropped, significant losses will occur if the landslide loses stability. In light of the problem, we collected monitoring data of Shuping landslide in recent years and analyzed its deformation mechanism in association with geological survey and exploration data. The results show that: 1) the fluctuation of underground water level of Shuping landslide is consistent with that of reservoir water level, but the variation of reservoir water level is relatively lagged; 2) hydrodynamic pressure occurs in the condition of decline of reservoir water level, which is unfavorable to landslide stability, at the same time, GPS data indicate intense deformation of the landslide with typical features of hydrodynamic pressure-type landslide; 3) monitoring results measured by auto-recording displacement meter show that overall deformation is the main kind of deformations for Shuping landslide after impoundment with water level of 175 m, and it has deformation features of tractive landslide whose deformation in the bottom leads to slip in the top.

Key words: Shuping landslide, landslide monitoring, hydrodynamic pressure, deformation mechanism, Three Gorges reservoir