Abstract: The state of slope activity is an important indicator reflecting the hazard level of landslide. Previous assessments of landslide are focused on the mechanism of landslide by selecting reasonable indicators to quantify the degree of hazard. However, such assessments take no consideration of the evolution process and activity states of slope, which could not precisely depict the risk level of landslide. In view of this, a risk assessment method for large landslide in consideration of slope activity state is proposed. The risk value of large landslide is calculated by superpositioning the geological conditions and the activity state in GIS. With the landslide of Xishan Village as an example, geological factors inclusive of slope gradient, slope height, curvature, slope direction, stratigraphic lithology, fault, river, road, and vegetation coverage are selected to construct an assessment model with fracture development degree and monitored deformation to describe the activity state of slope. Verification results show that the degree of overlapping between highly active area and highly risky area reaches 96.03%, which indicates that the proposed risk assessment model is reasonable and effective.

Key words: landslide, risk assessment, state of slope activity, assessment factors, GIS, Xishan village landslide