Early Detection And Monitoring Of Potential Landslides In Southwest Mountainous Area Based On Remote Sensing Technology

Southwest mountainous areas have steep mountain slopes,complex terrain and geological conditions,and strong neotectonic movements.In recent years,large-scale catastrophic landslide events have occurred,and they are alaways located at high positions and are highly concealed.So it’s very difficult to dectect and obtain deformation by traditional technologies.In recent years,the rapid development of remote sensing ground observation technology has provided the possibility of early identification and mid-to-long-term monitoring of high-level and high-concealment landslide hazards in southwestern mountain areas,such as InSAR technology.In this paper,high-resolution optical satellite images and interferometric synthetic aperture radar technology are used to detect potential landslides in the upstream of the Baige Landslide within 30 km and downstream areas of the Baige Landslide within 100 km.Then quantitative deformation monitoring was conducted for typical landslides based on multi-temporal optical remote sensing images and time-series InSAR technology.The results of deformation monitoring have been used to complete potential landslides instability assessment and river blocking risk analysis,including deformation rate,historical deformation variables,deformation area and so on.The main research results of this paper are as follows:(1)Characteristics analysis and identification index establishment of optical remote sensing image about potential landslides.In the early identification of landslide hazards based on optical remote sensing images in the study area,first of all,the optical remote sensing images of typical landslides in recent years were collected and analyzed to determine optical remote sensing identification indicators of similar landslide hazards.Then the identification indicators were applied in the study area,and 51 potential landslides were identified.(2)Potential landslides detected by InSAR technology and the applicability analysis of InSAR technology detection in mountainous areas.Choosing 5 typical area to finish InSAR analysis of landslides so as to summarize how to select SAR data source and processing methods under different conditions,including different vegetation coverage and different deformation rates.Then complete the applicability analysis of InSAR technology to the landslides in mountainous areas,especially in the southwestern mountainous areas.Finally select the appropriate SAR datas,which are Sentinel-1 ascending and descending datas,and use the appropriate InSAR method to detect the potential landslides of study area,and then compare with the results of optical remote sensing interpretation.There are 16 landslide hazards,5 of which are detected separately by InSAR technology.(3)Deformation monitoring of typical landslides and risk analysis of river blockage.On October 11 and November 3,2018,two large-scale landslides occurred in the upstream of the Jinsha River near the Baige Village.Whether drainage by manual intervention aggravated the detected landslides has become the social focus issue.Three typical landslide hazards were selected,based on multi-temporal Planet satellite imagery and SBAS-InSAR technology,quantitative deformation monitoring of these three typical landslide hazards was completed,and then combined with the quantitative monitoring result to analyze the risk of the river blockage.