Early Identification, Monitoring, and Warning of Landslide Hazards in Steep Mountainous Areas using InSAR

The geological conditions in the alpine gorge regions of western China are complex, with widespread and frequent disasters that result in hundreds to thousands of deaths and billions of yuan in direct economic losses annually. Currently, nearly 300,000 potential geological hazard sites have been identified in China, yet over 70% of the geological hazards that lead to disastrous consequences occur outside these known potential hazard areas. Therefore, conducting early and precise identification of large-scale landslide hazards is of great significance for enhancing China's geological disaster prevention and control capabilities. Interferometric Synthetic Aperture Radar (InSAR), due to its characteristics of large coverage, all-weather measurement, and non-contact measurement, has been widely used and valued in the early identification and monitoring of landslide hazards. However, in engineering applications of early landslide hazard identification using InSAR technology, there are issues such as geometric distortions caused by SAR satellite oblique viewing that are unclear in terms of how to accurately identify them on a large scale and their impact on InSAR monitoring, as well as the quantitative relationship between detected Line of Sight (LOS) deformation and true deformation, and the unclear removal methods for atmosphere-related and spatially heterogeneous atmospheric effects caused by unique topographies in alpine gorge regions when external data are not available.

This study reviews the current application status of InSAR technology in the early identification and monitoring of landslide hazards, and clearly and innovatively addresses the key issues in its engineering applications, such as limitations in spatial detection capabilities, LOS detection sensitivity, and atmospheric correction methods in mountainous areas. It also summarizes the application characteristics and future prospects of InSAR technology, which is of great significance for effectively conducting engineering applications of InSAR technology in geological disaster prevention and control.