Research on characteristics and failure mechanism of Guizhou Shuicheng landslide based on InSAR and UAV data

Abstract

Studying the failure mechanism, process and triggering factors of landslides has important significance for the identification, monitoring and early warning of hidden dangerous landslides in similar environments. On July 23, 2019, a landslide occurred in Shuicheng County, Liupanshui City, Guizhou Province. After the disaster, InSAR, satellite time-series imagery, and UAV emergency surveys were quickly used to study and analyze the natural geographic conditions, characteristics and failure mechanisms of the landslide. Studies have shown that the main triggering factors of the landslide were regional continuous rainfall. Additionally, this disaster was also related to road construction, regional topography and stratum lithology. According to the InSAR results, the landslide area had a weak surface deformation of approximately 5 ​mm per year beginning two years ago. However, this deformation was not sufficient to initiate the landslide. The accumulated rainfall in July reached 372.1 ​mm in the landslide area, and the rainfall on the landslide day was 48.8 ​mm, reaching the level of heavy rainfall. This landslide occurred on a loose basalt weathered residual soil layer that provided optimal geological conditions for the landslide, while the convex bank formed by roadworks provided the optimal topographical conditions. These elements together caused the landslide.

Keywords

• Landslide
• UAV
• InSAR
• Emergency investigation
• Failure mechanism