Abstract: Affected by the fluctuation of reservoir pooling water level, the movement of a colluvial landslide in the Three Gorges reservoir area exhibits the non-uniform behavior and the distinct zoning characteristics. The conventional deformation monitoring means (such as total station, GPS, GNSS, etc.) can only achieve limited point data collection at important locations on the landslide mass and cannot detect deformation in unmonitored areas. Based on the physical model test, a three-dimensional laser scanning technology and the geographical and temporal weighted regression model (GTWR) are used to study the surface deformation pattern of the colluvial landslide at different pooling water storage levels. The results show that the laser point cloud of the slope surface deformation can present the characteristics and the overall deformation trend of the landslide intuitively and find the deformation phenomenon that is difficult to be identified by the naked eye or outside the monitored area, which can be an important supplement for point monitoring. The GTWR performs well in fitting the surface deformation of the landslide slope for considering the non-stationarity of space and time.

Key words: Colluvial Landslide, Surface Deformation, Model Tests, Geographical and Temporal Weighted Regression Model