Research On Ground Deformation Monitoring And Early Landslide Identification Using InSAR Technique

China is a country with frequent geological disasters.Every year,huge economic losses and casualties were caused by geological disasters cause.Landslides are often accompanied by surface deformation.YingJiang County is located in the transition zone between Tengchong-Longling Earthquake Belt and Burma Arc Seismic Belt.The geological environment is complex and landslide disasters occur frequently.Therefore,taking YingJiang County as an example to carry out surface deformation monitoring and early identification of landslides has important theoretical and practical significance.There are many ways to monitor surface deformation.Synthetic Aperture Radar Differential Interferometry(D-InSAR)has the advantages of all-weather,wide coverage,rapid deformation monitoring and low cost.It has become an important means of early landslide disaster monitoring in recent years.Based on the above theoretical foundation and practical needs,this article has conducted research from the following aspects,the research content and conclusions are as follows,(1)The division of slope units and the extraction of terrain factors.Based on DEM data,divide the slope unit in the study area,and extract terrain factors such as slope and aspect.The study area is divided into 845 slope units.The smallest slope unit area is 1.08km2,the largest slope unit area is 42.4km2,and the average slope unit area is 6.01km2;Using the ArcGIS surface extraction tool,the slope and aspect factors of the study area were obtained.The study area was dominated by 7°-15° and 15°-25°,accounting for 32.41% and 33.86% of the main body,respectively,and the slope distribution was relatively uniform.(2)Monitoring of surface deformation.Based on sentlnel-1A SAR images,D-InSAR technology(differential interferometry)and PS-InSAR technology(permanent scatterer interferometry)were used to obtain the phased surface deformation and long-term sequence deformation characteristics of the study area.The negative deformations in the study area are mainly distributed along the Penang River,Daying River,Sudian Lisu Township,Menglong Township,Xima Town and Nabang Town.(3)Land use classification.Based on Landsat8 OLI data,a variety of band combination and support vector machine classification methods are used to classify the land use in the study area,and the land use types in the study area are divided into six types: construction land,bare land,sand land,forest land,grassland,and cultivated land.And verify the accuracy of land use classification,and remove the PS points with large inversion error based on the land use situation.(4)Early identification of hidden landslide hazards.The combination of topographic factors,land use index,and surface deformation law can realize the identification of landslide hidden slope units in the study area,and based on historical disaster points and field surveys and tests,the early identification results of landslides in the study area are credible.