Abstract: With the gradual development of infrastructure construction in western China,the consolidation of linear projects such as mountainous highways and railways has become a top priority for regional development.However,the complex terrain structure in the southwestern mountainous areas makes manual surveying for highway construction labor-intensive and inefficient,posing challenges for comprehensive hazard identification along the routes.With the rapid advancement of multi-source remote sensing and monitoring technologies,the "space-air-ground" integrated investigation system offers a novel solution to the challenges of geological hazard surveys for mountainous highways.This paper involves: firstly,employing satellite InSAR technology for large-scale deformation zone screening along highways; then,utilizing airborne LiDAR systems and oblique photogrammetry modules for detailed investigations of key hazard-prone areas; and finally,conducting on-site surveys along with surface and slope internal monitoring to verify and assess potential geological hazards.Taking a specific expressway as the study case,this paper applies the above methodology to conduct geological hazard investigations along the route,identifying 2 deformation zones and 119 potential hazard sites.The study demonstrates that the "space-air-ground" integrated hazard investigation system provides a new approach for the early identification,warning,and prevention of geological hazards along mountainous highways,while also offering critical technical support for regional disaster prevention and mitigation.

Key words: mountain expressway, geohazards investigation, space-air-ground integrated perspective, InSAR technique, LiDAR technique