Monitoring And Analysis Of Surface Deformation In Baili Dujuan Mining Area,Guizhou Based On InSAR Technology

The mining activities of mineral resources have changed the original geological environment to varying degrees,causing geological disasters such as surface subsidence and collapse.Therefore,it is necessary to monitor the subsidence of the mining area.The traditional monitoring method is to monitor the settlement of points,such as setting up fixed monitoring stations and periodic mobile station observations.Station-based monitoring lacks comprehensive control of regional settlement,and is time-consuming,laborious and vulnerable to weather.Synthetic Aperture Radar Interferometry(Interferometry Synthetic Aperture Radar,InSAR)is an emerging surface deformation monitoring technology,which has the characteristics of monitoring large-area surface deformation all-time and all-weather,and the monitoring accuracy can reach the millimeter level,meeting the needs of engineering applications.For this reason,this article takes the Baili Dujuan mining area in Guizhou as the research object,selects Cband Sentinel-1A data,and uses SBAS-InSAR technology to calculate the deformation of the radar line of sight(LOS)to the surface of the mining area;in addition,the surface coverage and topography of the mining area are complex,for this reason Carry out the combination of ascending/descending orbit images to calculate the vertical and east-west deformation of the mining area,and analyze the deformation and the deformation direction of the mining area in two directions,so as to solve more accurate surface deformation.The main research results and conclusions of the article are as follows:(1)Analysis of surface deformation and settlement reasons in mining area.Select the Sentinel-1A orbit data from 2017 to 2020 in the mining area,and use the SBASInSAR technology to calculate the LOS to the surface deformation.From the map of the average annual surface deformation rate of ascending orbit,three obvious hidden danger areas of surface subsidence are delineated,and the horizontal and vertical section lines are drawn to the hidden danger areas of subsidence,starting from the three aspects of the law of surface movement and deformation in the mining area,mining data and on-site field investigations.Analyze the difference in deformation range and deformation rate of the mining area in each time period.(2)The surface deformation calculation and difference analysis of the mining area combined with the ascending/descending orbit image.Firstly,the surface deformation of the descending orbit LOS is calculated,and the average velocity standard deviation is inverted according to the ascending/descending surface deformation results.The results show that the SBAS-InSAR technology has good stability in extracting the surface deformation results.Comparing the surface deformation results of ascending/descending orbit,it is found that there are certain differences in deformation rate,deformation location,etc.The analysis is caused by the flight direction of the ascending/descending orbit image and the geographical conditions of the mining area.(3)Three-dimensional surface deformation calculation and analysis of mining area based on ascending/descending orbit images.Taking the Baili Dujuan mining area in Guizhou as an example,the vertical and east-west deformation fields of the mining area are calculated based on the ascending/descending orbit image.According to the vertical and east-west deformation results,three hidden surface subsidence areas are delineated within the mining area,and the deformation and deformation range of the hidden subsidence areas are analyzed based on the deformation movement law.It is found that as the mining area continues to be mined,the subsidence will be affected.Affect the production and life of nearby residents.In summary,this paper uses SBAS-InSAR technology to monitor the surface deformation of the lifting rail data in the Baili Dujuan mining area,and further calculates the three-dimensional surface deformation of the mining area on this basis.The technical ideas and results formed in the article provide strong technical and data support for the prevention and control of the geological environment in the mining area,and have important engineering reference value.