Landslide Susceptibility Assessment Of Dafang And Nayong County Of Guizhou Provience Combining With PS-InSAR

Landslide geological hazard has the characteristics of wide distribution,high frequency and destructive.The occurrence frequency of landslides is relatively high in China.Almost landslide disaster will threaten and endanger the public's life safety and result in major material losses.The evaluation of landslide susceptibility can effectively predict the risk and spatial distribution of landslide hazards,and the results of the prediction can enhance the landslide investigation and practice.The evaluation of landslide susceptibility can lay a foundation for landslide hazard warning,land use planning and landslide risk management.However,the evaluation of landslide susceptibility is generally based on static geographic information data such as elevation,slope and slope direction,etc.The landslide susceptibility map is not updated for many years,which cannot reflect the actual situation of the current landslide.In recent years,PS-InSAR technology has become an effective method for landslide monitoring.The biggest advantage of this method is that it can effectively and timely monitor the surface displacement and find the surface deformation.Therefore,the correction matrix is used to refine the deformation information obtained by PS-InSAR technique to the conventional landslide susceptibility map,and a more effective map of landslide susceptibility will be obtained.In this study,Dafang county and Nayong county of Guizhou province are taken as the research area.On the basis of the conventional landslide sensitivity map assessment,the deformation data obtained by PS-InSAR technology is used to modify the landslide susceptibility map.The specific work of this paper is as follows:(1)PS-InSAR technology was used to process the data of 26 scenes ascending radarsat-2 with a resolution of 5 meters and 41 scenes descending sentinel-1 with a resolution of 20 meters in study area,getting the deformation information of PS points,and drawing the surface deformation rate diagram.(2)Based on the natural geographical conditions of landslide in the study area,we selected 7 influencing factors including elevation,slope,slope direction,faultzone,river,mining area and road.The weight of each factor is obtained by using information amount and logistic regression model.And finally we getting landslide susceptibility map.(3)Based on the correction matrix to update the original landslide susceptibility map,we adjust the sensitivity of each pixel and get the final landslide susceptibility map.(4)Combined with the actual situation,we analyze the updated landslide susceptibility map and its causes.(5)the superposition analysis was conducted between the landslide verification points and the landslide susceptibility map of the study area.Compared with the traditional landslide susceptibility map,the landslide susceptibility map based on PS-InSAR technology was more accurate and the results were more reliable.