PS-InSAR post-processing for assessing the spatio-temporal differential kinematics of complex landslide systems. A case study of DeBeque Canyon Landslide (Colorado, USA)

The complex superimposition of different kinematics and nested sectors within landslide systems amplifies the challenge of interpreting their heterogeneous displacement pattern and targeting effective mitigation solutions. As an example of such peculiar spatio-temporal behaviour, the DeBeque Canyon Landslide (Colorado, USA) is emblematic of the application of interferometric post-processing analysis for a detailed, remotely-based investigation. We employed a multi-geometry Persistent Scatterers (PS) InSAR dataset to provide continuous information on the spatiotemporal scale and achieve a solid representation of the segmented kinematics and timings. Using an updated geomorphological map of the landslide system, we performed a two-dimensional decomposition of the Persistent Scatterers (PS) dataset to determine the displacement orientation and inclination for each internal sector of the landslide system. We then conducted statistical analyses on the displacement vector characteristics and time series data. These analyses enabled us to spatially characterize the segmented activity patterns of the landslide system and identify abrupt changes in trends associated with preparatory and triggering factors. A clear differentiation of the rotational or translational kinematics within the landslide system was accomplished solely using surface displacement measures. Moreover, the application of a Bayesian model on the bi-dimensional vector time series leads to the identification of significant differences in the deformational behaviour of each sector with respect to precipitation and temperature factors. Our approach represents a replicable method for local-scale characterization and monitoring of landslides exhibiting complex spatio-temporal displacement patterns and providing an effective, low-cost solution for transportation agencies from a risk-reduction perspective.