Space-Air-Ground Integrated Approach for Landslide Identification and Characterization in High-Altitude Mountainous Regions: A Case Study in Shannan, Xizang, Himalayas

Geological hazard investigation in high-altitude mountainous regions is challenging due to complex terrain, limited accessibility, and the need to identify potential hazards over large areas while characterizing their local features. This study develops and applies a sequential, multi-scale space–air–ground workflow integrating Sentinel-1 SBAS-InSAR, UAV photogrammetry, airborne LiDAR, and field investigations in Shannan, Xizang, China. Sentinel-1 SBAS-InSAR analysis identified 65 deformation anomaly areas covering a total of 139 km2. Based on a comparison with existing geological records and field surveys, eight landslide sites were identified as new discoveries. UAV and LiDAR techniques were subsequently employed, together with field investigations, to examine the identified anomalies and characterize their topographic and geomorphological features. Integrated hazard model maps were completed for 20 geological hazard sites, and two representative cases were selected for detailed analysis: the slowly creeping landslide in Cuodui Village and the rockfall at Mawujue Temple. These cases illustrate the need to interpret deformation signals in conjunction with hazard type, terrain characteristics, and field evidence. The results highlight the practical value of integrating satellite-based deformation monitoring, high-resolution three-dimensional terrain characterization, and field investigations within a coherent workflow for geological hazard identification and characterization. The workflow provides a practical reference for investigations in comparable high-altitude mountainous regions, although its transferability depends on local terrain conditions and data availability, and its effectiveness in identifying previously unrecorded hazards requires further validation.