Regional Recognition and Classification of Active Loess Landslides Using Two-Dimensional Deformation Derived from Sentinel-1 Interferometric Radar Data

Abstract

Identification and classification of landslides is a preliminary and crucial work for landslide risk assessment and hazard mitigation. The exploitation of surface deformation velocity derived from satellite synthetic aperture radar interferometry (InSAR) is a consolidated and suitable procedure for the recognition of active landslides over wide areas. However, the calculated displacement velocity from InSAR is one-dimensional motion along the satellite line of sight (LOS), representing a major hurdle for landslide type and failure mechanism classification. In this paper, different velocity datasets derived from both ascending and descending Sentinel-1 data are employed to analyze the surface ground movement of the Huangshui region (Northwestern China). With global warming, precipitation in the Huangshui region, geologically belonging to the loess basin in the eastern edge of Qing-Tibet Plateau, has been increasing, often triggering a large number of landslides, posing a potential threat to local citizens and natural and anthropic environments. After processing both SAR data geometries, the surface motion was decomposed to obtain the two-dimensional displacements (vertical and horizontal E–W). Thus, a classification criterion of the loess landslide types and failure mode is proposed, according to the analysis of deformation direction, velocities, texture, and topographic characteristics. With the support of high-resolution images acquired by remote sensing and unmanned aerial vehicle (UAV), 14 translational slides, seven rotational slides, and 10 loess flows were recognized in the study area. The derived results may provide solid support for stakeholders to comprehend the hazard of unstable slopes and to undertake specific precautions for moderate and slow slope movements.

Retrieving the Kinematic Process of Repeated-Mining-Induced Landslides by Fusing SAR/InSAR Displacement, Logistic Model, and Probability Integral Method

“…Based on the incidence angle shown in Figure 7a, the displacement direction of the slope is toward the LOS direction of the ascending SAR satellite. If the displacement toward the west direction is greater than that of the vertical downward direction, it will be easily prone to this anomalous phenomenon [47][48][49][50].…”

Multi‐temporal InSAR analysis to monitor landslides using the small baseline subset (SBAS) approach in the Mila Basin, Algeria

“…Specifically, the landslide crown showed steep vertical deformation at the top zone reaching 1 m. After 3 days, the aftershock caused landslide reactivation to the west (the growth of the landslide), mainly at the same location of the landslide crown with an increment in the downward subsidence to be 2 m. Vertical velocity of −30 mm/year, and the flanks showed lateral shear movement causing tilting and damage to the inhabitants' building, providing this region with a horizontal displacement rate of −10 mm/year to the west. Although the landslide's toe (found at the accumulation zone) exhibited arc‐shaped fissures, its dominant direction tended to be E‐W displacement at a rate approximately −20 mm/year due to radial cracks (see Figures 6 and 7) (Intrieri, Frodella, Raspini, Bardi, & Tofani, 2020; Meng et al, 2020; Peng, Xu, Liu, et al, 2018). The velocity profile was plotted with the geological cross section shown in Figure 10a, considering the thickness of the clay layer (150 m depth) and the characteristics of being affected by the repeating wet–dry seasons (Figure 11a; North et al, 2017).…”

Reply on CC1

“…-Use the InSAR in the aftermath of an earthquake in order to identify the geotechnical disorders, their extent and locations. The Differential radar interferometry and the Coherence Changes Detection are the most adapted methods for ground and soil surfaces changes detection (Jung and Yun, 2020;Meng et al, 2020;Pawluszek-Filipiak and Borkowski, 2020;Tampuu et al, 2020;Tzouvaras et al, 2020). A city, Mila, in Northern Algeria, is considered as the pilot study.…”