Early Identification And Monitoring Of Landslides Based On Optical Remote Sensing And InSAR Technology

Guizhou Province is located in the southwestern of China.Due to its complicated topography and climatic conditions,geological disasters occur frequently,and the main disaster is a landslide.In recent years,the number of deaths and disappearances caused by the landslide disaster in Guizhou Province ranks among the highest in the country.The economic losses caused by landslides are huge,and infrastructure is under great threat.In order to avoid and mitigate the losses caused by landslides,it is necessary to identify the hidden dangers of landslides.Therefore,this paper conducts surface deformation monitoring and landslide identification in the areas of Liupanshui,Guiyang,and Tongren to search for potential landslides.This paper monitors the landslides that are the focus of attention and analyzes the status and movement trends of the landslides.This paper analyzes the formation mechanism of landslides and the possible causes of landslides in areas where landslides have occurred.This study solves the problem of difficult monitoring of landslides in mountainous areas.This study has important significance for regional landslide control and disaster prevention and mitigation.With the development of radar technology,InSAR technology has become an effective new technology for surface deformation observation,and has a wide range of applications.In recent years,the research of InSAR technology applied to landslide identification and monitoring has been increasing.However,there are some uncertainties in the results of using surface deformation monitoring to identify landslides.Therefore,this paper combines several methods to identify landslides and monitor the landslide areas that are the focus of attention.The main work and results of this paper are as follows:(1)This paper used SBAS technology to process 152 Sentinel-1A radar satellite images covering the research areas of Liupanshui,Guiyang,and Tongren.This paper obtained the surface deformation information of Liupanshui research area from August 06,2018 to August 27,2019,the surface deformation information of Guiyang research area from March27,2017 to June 21,2019,and the surface deformation information of Tongren research area from August 08,2018 to June 28,2019.This paper identified severely deformed areasas dangerous deformation areas.Finally,102 dangerous deformation zones were identified,including 43 in the Liupanshui research area,40 in the Guiyang research area,and 19 in the Tongren research area.(2)This paper used optical remote sensing images to identify landslides based on the identified dangerous deformation areas.Typical landslide areas were used to establish optical image interpretation identification marks to identify landslides in dangerous deformation areas.Through interpretation and identification,this paper identified 16 landslide areas,and identified 72 deformation areas caused by construction or mining and other reasons,and also identified 14 areas that may have landslides.(3)For dangerous deformation areas that may have landslides,this paper adopts the landslide identification method based on NDVI time series analysis and the landslide identification method based on environmental elements required for landslide development.In order to ensure the accuracy of potential landslide identification,the results of the two identification methods are integrated.Finally,a total of 12 potential landslide areas and 2 unstable slopes were identified.(4)This paper used InSAR technology to monitor three landslides in the study area.The SABS technology was used to obtain the surface deformation information of the landslide area,and the time series deformation analysis of the landslide was also carried out.The results show that the deformation of the landslide in Jichang Town was small before the disaster,and the landslide was mainly caused by heavy rainfall.The displacement rate of Yujiaying landslide and Fana landslide is both above-20 mm / yr.There are obvious signs of subsidence in the two slopes,and there is a tendency to continue to subsidence.These two landslides need to be focused on in the future.