Landslide Susceptibility Risk Assessment And Surface Subsidence Prediction Model Applicability Analysis In The Black Hills Gorge Area

Landslides and subsidence are important factors affecting the development of a region.In order to achieve early warning of non-instantaneous natural disasters such as landslides,it is essential to identify landslide hazard areas and carry out corresponding preventive measures in advance to reduce damage.In this paper,using the Heiheishanxia area of the Yellow River as the study area,nine factors such as elevation,slope,curvature,NDVI and active faults were selected as evaluation indicators based on an informative evaluation model to carry out zoning evaluation of landslide hazard susceptibility in the study area by collecting data from multiple sources.Using Sentinel-1A satellite data as the data source,the processing of Sentinel-1 A satellite data was carried out using InSAR technology to analyse SAR images of the Heishanxia area at different times and to obtain information on the subsidence,uplift,displacement and other minor deformations of the ground surface occurring at different times,so as to achieve highprecision monitoring of the ground surface movement.On the basis of the above work,experiments were designed to compare and analyse the average subsidence in the three characteristic areas in the Heishanxia area based on InSAR as the data base with the results predicted by three prediction models,to explore the applicability of the surface subsidence prediction models in the Heishanxia area,and to provide a scientific basis for future geological hazard research in the Heishanxia area.The results show that:(1)In this paper,nine factors of elevation,slope,curvature,stratigraphic lithology,fault,water system,NDVI,road and rainfall were selected as the evaluation indexes of landslide susceptibility in the Heishanxia area,and a zoning of landslide hazard susceptibility in the Heishanxia area was constructed.The results of the zoning are in high agreement with the existing research results in the region,and the conclusions are reliable.The results show that the high-risk areas for landslide hazards in the study area are located in the Shapotou District of Zhongwei City in the northeast,in Jingyuan County in the south,and along the main rivers and roads,mainly because of the relatively soft rocky strata in these areas,which are mostly loose materials such as sandy loess.(2)Based on 17 phases of Sentinel-1A satellite data from April 2020 to May 2021,comparing the results of surface deformation monitored by D-InSAR and PS-InSAR,the results are basically consistent in terms of deformation levels and spatial distribution,and the results obtained by PS-InSAR are more reliable,with the subsidence information based on the InSAR-monitored study area as the The GNNM(1,1)model has the lowest prediction error and the GNNM(1,1)model has higher prediction accuracy and stability,which can better adapt to the real situation in the study area of Heishan Gorge and can be used as a reliable prediction model to further study and predict the future subsidence deformation in the area.