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Understanding landslide kinematics, their characteristics, and contributing factors is crucial for decision-making regarding mitigation strategies for infrastructure projects. These characteristics depend on the geomorphology of the area, climate, and proximity to water bodies and anthropogenic activity. Some geomorphological features are shared between some western Canadian regions, particularly within the Canadian Interior Plains (Interior Plains). This paper synthesizes the failure mechanisms, kinematics, triggering events, and contributing factors associated with 11 landslides in the Interior Plains, with detailed qualitative descriptions of two of them. The paper discusses the commonalities of bedrock formations that contain thin sub-horizontal and continuous deposits of weak materials as the main geomorphological predisposing factor for landslides in this region. The findings show commonalities in the effect of seasonal fluctuations in the characteristics of water bodies in contact with these landslides, driving episodes of landside reactivation, acceleration and deceleration. Importantly, anthropogenic activity as a trigger for the initiation of some of these landslides suggests a high susceptibility of certain slopes in the Interior Plains to instability resulting from relatively small changes in in-situ stresses. This information becomes critical for assessing the landslide susceptibility of valley slopes in this region for infrastructure planning, design, and operation. [ABSTRACT FROM AUTHOR]

The Thompson River valley is one of the most important transportation corridors in western Canada as it hosts two important railways. This valley has experienced several historical landslide events, many of them along a 10 km section south of the town of Ashcroft. Six of these landslides, showing varying states of activity, were selected for analysis in this paper, as these have the potential for the biggest impact on the railways. The subsurface interpretation of these landslides is combined with satellite InSAR data from May 2015 to May 2017 to enhance the current understanding of the landslide kinematics. Two InSAR orientations are combined geometrically with the assumption that the horizontal component of landslide movement is parallel to the slope azimuth, which provides a practicable approach to approximate landslide displacement vectors. The results classify these landslides as very slow-moving. The maximum velocities recorded are 29, 35, 26, 64, 18, and 52 mm/year for the Goddard, North, South, South extension, Barnard, and Redhill landslides, respectively. All landslides except the Redhill landslide show near-horizontal movements near the toe, with increasing vertical components as measurements approach the back scarp. This confirms that kinematics include rotational and compound mechanisms. [ABSTRACT FROM AUTHOR]

The Thompson River valley hosts 14 landslides along a 10 km section, which threaten the two major railroads connecting the Port of Vancouver and the interior provinces in Canada. The Ripley landslide is one of the active landslides in this section of the valley. Previous research at this site included an analysis of landslide deformations using satellite radar interferometry focusing on deformations measured in the line of sight between the satellite and the slopes, and average downslope displacement (deformations projected in the average downslope direction). Since then, further stratigraphic interpretation has provided an enhanced understanding of the Ripley landslide. In this update, the new stratigraphic interpretation is supplemented with satellite InSAR data from May 2015 to May 2017 to enhance the current understanding of the landslide kinematics. The results indicate that the Ripley landslide has been moving at a rate between 2 and 82 mm per year, corresponding to a very slow to slow landslide. It is also observed that the movements tend to be near-horizontal on areas closer to the toe of the landslide, while the vertical component of deformation increases near the scarp of the landslide. This, together with the interpreted stratigraphy, indicates the kinematics corresponds to a compound landslide. This is consistent with interpreted landslide kinematics of older, more mature landslides in the area that have shown episodes of retrogression and suggests the possibility of a similar future behaviour of the Ripley landslide. [ABSTRACT FROM AUTHOR]