A Robust SAR Speckle Tracking Workflow for Measuring and Interpreting the 3D Surface Displacement of Landslides

Abstract

We present a workflow for investigating large, slow-moving landslides which combines the synthetic aperture radar (SAR) technique, GIS post-processing, and airborne laser scanning (ALS), and apply it to Fels landslide in Alaska, US. First, we exploit a speckle tracking (ST) approach to derive the easting, northing, and vertical components of the displacement vectors across the rock slope for two five-year windows, 2010–2015 and 2015–2020. Then, we perform post-processing in a GIS environment to derive displacement magnitude, trend, and plunge maps of the landslide area. Finally, we compare the ST-derived displacement data with structural lineament maps and profiles extracted from the ALS dataset. Relying on remotely sensed data, we estimate that the thickness of the slide mass is more than 100 m and displacements occur through a combination of slumping at the toe and planar sliding in the central and upper slope. Our approach provides information and interpretations that can assist in optimizing and planning fieldwork activities and site investigations at landslides in remote locations.

A Scientometric Analysis of Predicting Methods for Identifying the Environmental Risks Caused by Landslides

“…According to ALS, which investigated the morphology of two huge landslides in Idaho (USA) at various spatial scales, mass movement geometry and kinematics are minimized by using geomorphometry with high resolution DEMs, such as laser scanners. A number of factors, including aircraft altitude, LiDAR quality, topographic surface layout, and vegetation effects, affect the feasibility of DEMs and 3D models produced by ALS [61]. Because of the difficult terrain and extensive vegetation in the mountains of western China, inSAR displacement estimates are inherently more unreliable.…”

Response of a large deep-seated gravitational slope deformation to meteorological, seismic, and deglaciation drivers as measured by InSAR

“…The surface of Fels slide exhibits geomorphic evidence typical of DSGSDs, which includes lineaments, antislope scarps, benches, rotational half-grabens, anomalous depressions, and mid-slope ponds. These features, particularly the lineaments, display three principal trends (Donati et al, 2021), suggesting a significant control of geological structures on their development and evolution. The spatial relationship between slope benches and lineaments indicates that the entire slope can be divided into large domains (10 2 to 10 3 m across) that deform differentially relative to one another.…”

“…The spatial relationship between slope benches and lineaments indicates that the entire slope can be divided into large domains (10 2 to 10 3 m across) that deform differentially relative to one another. The movements in the rock mass exploit dipping foliation planes within the metasedimentary bedrock (Donati et al, 2021). The western part of the slope has a prominent gravitational bulge near the base.…”

“…Our investigation builds on a geological characterization of the slope (Newman, 2013) and a recent remote sensing-based characterization (Donati et al, 2021) by using state-of-the-art satellite remote sensing methods to characterize movement of this very large DSGSD over a 24-year period between 1993 and 2017. We test the ability of an independent component analysis (ICA) algorithm on a long time series of InSAR data to determine if discrete, independently moving displacement domains can be identified within a slope deformation complex using the Fels slide as test case.…”

Kinematic Analysis of the 2020 Elliot Creek Landslide, British Columbia, Using Remote Sensing Data

“…A reduction in kinematic constraint (i.e., an increase in kinematic freedom) can involve the development of rupture and sliding surfaces within the slope or a decrease in frontal or lateral support of a displacing volume, promoting rock mass deformation or displacement along pre-existing surfaces. In this regard, the detachment of landslides may abruptly modify the kinematic configuration and cause instability to propagate to previously stable parts of the slope (Donati et al, 2021a;Fullin et al, 2021).…”