Potential landslides identification based on temporal and spatial filtering of SBAS-InSAR results

Abstract

Interferometric Synthetic Aperture Radar (InSAR) is an important method for acquiring surface deformation. Considering the difficulty of the identification work, the identification of landslides needs to be combined with the context of the pregnant disaster and the precipitating conditions. To identify potential landslides, we applied spatial and temporal filtering to the InSAR results, which consists of rainfall and landslide susceptibility mapping. In this paper, taking the Badong Ecological Barrier Zone of the Three Gorges reservoir area as the study area, the deformation aggregation areas in the study area were obtained by applying Small Baseline Subset InSAR (SBAS-InSAR) technology and spatial statistical analysis. We screened deformation aggregation areas by combining the susceptibility map and the correlation analysis of rainfall and deformation. Field verification and investigation were conducted on the suspected deformation areas, and 11 landslides were found to have signs of deformation, two of them are newly discovered landslides. In addition, we selected one of the landslides, the Songjiawuchang landslide, and compared the InSAR results with the GPS accumulated displacement to verify the reliability of the results. This research demonstrated the feasibility of combining InSAR results with spatial susceptibility maps and monthly rainfall factors for landslides identification methods. Key policy highlights Applied Spatial filtering and temporal filtering on the InSAR results. Evaluated in conjunction with geological hazards themselves. Landslide identification accuracy significantly improved.