Factors Influencing Landslide Deformation from Observations in the Three Gorges Reservoir

Since the impoundment of the Three Gorges Reservoir in mid-2003, slope displacements have occurred and existing landslides have been reactivated. The movement are a threat to the community and the environment. High precipitation in the area increases landslide susceptibility. The relationships among landslide displacement, rainfall and reservoir drawdown were analyzed for the Baijiabao landslide with the Grey relational analysis approach and using eight years of monitored displacement. The results suggest that rainfall triggered the landslide deformation in the earlier years. Then reservoir drawdown and the combined effect of rainfall and drawdown became preponderant. The identification of the triggers is important for selecting mitigation measures and evaluating the risk due to slope movement.