Research On Landslide Hidden Danger Identification Based On InSAR And UAV Photography Modeling

Geological disasters are frequent in China,and every year they bring huge economic losses and personal safety injuries to the country.As a typical geological disaster,landslide is often accompanied by surface deformation when it occurs,so monitoring surface deformation can identify landslide potential hazards.The western part of Lamping County,the study area of this paper,is located above the seismic zone of Biloxi Mountain,and the territory is cut down by the Lancang River gorge,which has a complex geological environment and frequent landslide hazards.Therefore,it is of great theoretical and practical significance to monitor surface deformation and identify landslide hazards in Lamping County as an example.There are various ways of surface deformation monitoring,among which synthetic aperture radar interferometry(InSAR),as a technology with the advantages of adapting to all-weather,wide coverage area,rapid deformation monitoring and low cost,has become an important means of early landslide hazard monitoring in recent years.Meanwhile,InSAR technology can be used as a census tool in the "three investigations" of geological hazards;UAV photographic modeling technology can identify the characteristics of landslide hazards intuitively and comprehensively,and is an important tool for detailed investigation in the "three investigations" of geological hazards.Based on the above theoretical basis and practical needs,this paper researches from the following aspects,and the research contents and conclusions are as follows.(1)Monitoring of surface deformation in Lamping County.Based on Sentinel-1A SAR images,SBASInSAR(Small Baseline Set Interferometry)technique was used to obtain the characteristics of the phase surface deformation and long time series deformation in the study area.The negative deformation in the study area is mainly distributed in the Bieluo Xueshan Mountain Range,the central area of Lanping County and the southern area of Lanping County.The types of landslide hazards in Lamping County can be summarized as three types:rainfall type,foot erosion type and human disturbance type.(2)UAV photography and 3D realistic modeling.In this study,three typical landslide hazards in Xinchang Village,Cheyiping Village and Qingdianwan Mining Area in Lamping County were selected for UAV aerial photography and 3D realistic modeling,and the landslide hazards area,hazards scale and hazards characteristics were identified through the realistic 3D model.(3)Landslide hazard identification and deformation analysis.The information on the deformation of landslide hazards in each time period was extracted by SBAS-InSAR technology and trend analysis was conducted.The analysis results show that the landslide hazard in Xinchang Village is a typical landslide hazard controlled by precipitation factors,and the absolute value of its landslide deformation changes nearly 600mm during the rainy season from June to October.the landslide hazard in Cheyiping Village is mainly influenced by the foot of the hill eroded by Lancang River,and the precipitation in the area is less,and the trend is not obviously influenced by precipitation.The deformation trend of Qingdianwan mine area is not significant,and the surface is more stable,so small-scale landslides will occur under precipitation conditions,but it is difficult for large-scale landslide disasters to occur.Based on the above study,it can be determined that the combination of InSAR technology and UAV photographic modeling technology can play an important role in the identification of landslide hazard potential.The information of surface deformation is firstly obtained by InSAR,and then combined with the trend analysis of surface deformation and the means of 3D modeling to identify the early landslide hazards,which can well identify the development characteristics and deformation conditions of landslide hazards.