Abstract:

The Dadu River catchment in the eastern Tibetan Plateau is one of the most developed areas of ancient landslides in the world. Due to the increasing human engineering activities and the frequent heavy rainfall occurrence, the problem of ancient landslide resurrection in the Dadu River catchment has become increasingly serious. In this study, we selected the ancient landslide group at Taipingqiao county, and used multi-source remote sensing technology of Unmanned Aerial Remote Sensing (UAV) and Interferometric Synthetic Aperture Radar (InSAR) monitoring to analyze the resurgence deformation characteristics and mechanism of the landslide in the Gulozhai village. Based on the UAV aerial remote sensing images, the landslide deformation characteristics at Gulozhai can be clearly identified. Two sets of large tensional cracks extend horizontally through the upper and middle landslide bodies, and the large secondary landslide on the left of the leading edge indicate that the landslide shows overall resurgence signs. Based on the InSAR time-series monitoring results, we confirmed that the two-month heavy rainfall from May to June 2020 was the main trigger for the resurrection of the ancient landslide, which is still in continuous deformation. Under heavy rainfall or earthquake, the secondary landslide on the left of the leading edge may slide further and even trigger the overall slope destabilization and sliding in the Luozhai village. Our results on the deformation characteristics and mechanism of the landslide resurrection at Gulozhai based on multi-source remote sensing technology can provide effective technical support for disaster prevention and mitigation related to the resurrection of ancient landslides in the Dadu River catchment.

Key words: ancient landslide reactivation, Unmanned Aerial Vehicle (UAV), Interferometric Synthetic Aperture Radar(InSAR), genetic mechanism, Dadu River