Landslide Slip Surface Inversion Method and Engineering Practice Based on InSAR-GNSS Fusion

The depth and spatial morphology of a landslide slip surface are the key basis for analyzing landslide instability mechanisms, evaluating stability, and designing and implementing prevention and control engineering. Accurately obtaining the geometric parameters of a landslide slip surface is of great significance for the prevention and control of various landslide disasters. Taking a landslide in Zhaotong City, Yunnan Province as the research object, this paper integrates InSAR time-series deformation data and GNSS monitoring data, combined with UAV oblique photogrammetry DEM data, to obtain a high-precision landslide surface deformation field. Based on the optimization and improvement of the landslide slip surface inversion method using the principle of mass conservation, a series of improvement strategies are adopted, including data fusion to enhance the accuracy of the surface deformation field, multi-profile inversion for shape determination, geometric inversion for depth determination, and global optimization solving. Under the limited conditions of single-track data, the inversion of the landslide slip surface depth is accomplished. Verified by field engineering measurements, the inverted slip surface depth is consistent with the results of anti-slide pile drilling cores, borehole camera detections, and landslide deformation laws. Under the condition of limited monitoring data, this method can quickly and accurately invert the depth and spatial morphology of a landslide slip surface. It has the advantages of low data requirements, a concise calculation process, and strong engineering applicability. It can serve as an effective supplement to traditional geological survey methods, providing reliable technical support for the rapid acquisition of slip surface parameters, stability analysis, disaster assessment, and refined prevention engineering design for small and medium-sized landslides in the mountainous areas of Southwest China. Furthermore, it holds important theoretical value and practical significance for improving the intelligence and refinement level of geological disaster prevention and control in mountainous regions.