Abstract: Many landslides have occurred in Three Gorges Reservoir area. Since the impoundment of the reservoir, the reservoir pool water level changes periodically and the rainfall is abundant, which has an impact on the stability of slopes in the reservoir area. The Muping landslide in the Three Gorges Reservoir area was presented as a case history in this paper. The deformation mechanism of the landslide under the coupled effect of the rainfall and the reservoir pool water level is analyzed by using the combination of qualitative and quantitative methods throughout the field geological survey, the displacement monitoring and other data. The results show that the “stepped” phenomenon of the Muping landslide presents a small characteristic, and the large “stepped” phenomenon is accompanied by the large fluctuation of the reservoir pool water level and the obvious rainfall; When the reservoir pool water level drops, the landslide deformation response is more sensitive, because the head difference between the groundwater and the reservoir pool water level points out of the landslide. Single day heavy rainfall and the continuous rainfall can cause the landslide deformation, and the lag time of the peak rate in high pool water level operation stage is 9 days. The research results can provide a basis for the prevention and the control of Muping the landslide hazard and the study of similar landslides.

Key words: Three Gorges Reservoir Area, Landslide in Soils, Reservoir Pool Water, Rainfall