Abstract:
The revival of ancient landslide deposits often leads to serious damage of residential buildings,roads,power transmission towers,and other structures located above or below the landslide deposits. It is also a process of progressive deformation and spatio-temporal effect of crack generation and expansion,structure disintegration,and sliding failure of ancient landslide deposits. Based on six periods of multi-source high-resolution satellite remote sensing data and UAV images from 2007 to 2021,the relative displacement along landslide cracks was measured and the slip rate was calculated. In this paper,the deformation characteristics and crack spatio-temporal distribution of the ancient landslide deposits in Heiduo Village,in the upper reaches of the Bailong River Basin,were studied,and the failure modes and influencing factors were analyzed. The results show that:(1)the ancient landslide deposits are sliding slowly along the interface between the lower bedrock and the upper deposit,the marginal cracks have completely connected with close-up,and the internal swelling cracks develop and lead to the partial disintegration of the landslide body; (2)The relative displacements in the upper part of the ancient landslide deposit are larger than those in the lower part at both margins,showing the progressive deformation characteristics of a typical push-type landslide; (3)The ancient landslide deposit moves toward the right along the marginal cracks,resulting in the relative displacement and slip rate at the right part being larger than the corresponding values at the left part; (4)The annual slip rate of ancient landslide deposits is positively correlated with the annual rainfall and is also affected by the remote effect of the 2008 Wenchuan
MS8.0 earthquake and the disturbance of road-slope cutting. It shows that deformation measurement based on multi-source and multi-period high-resolution remote sensing data is an effective technique for detecting and predicting the deformation of ancient landslides and could provide helpful reference for other slow-moving landslides in the Bailong River.