Research On Surface Deformation Monitoring Of Mining Area Based On Multi-source InSAR Data

Coal resources arc an important energy source to support rapid economic development.Extensive mining of coal resources will lead to surface subsidence and horizontal deformation in mining areas.Carrying out efficient and accurate monitoring of surface deformation in mining areas can provide a data basis and scientific basis for the prevention and management of geological disasters in mining areas.Most of the traditional monitoring methods of surface deformation in mining areas are based on point monitoring,which have disadvantages such as high cost,low efficiency.and limited monitoring surface,making it difficult to meet the requirements of surface deformation monitoring in mining areas.In recent years,with the continuous development of space earth observation technology,InSAR as a mature surface deformation monitoring technology,has the advantage of not being affected by cloud and rain weather and time,and can realize all-weather earth observation.Since traditional D-InSAR technology is susceptible to decoherence and atmospheric delay during monitoring,this paper studies the surface deformation monitoring of mining areas based on time-series InSAR technology and multi-source InSAR data.The three-dimensional deformation field of the surface is extracted by using the three-dimensional solution model of the mining area,and the InSAR monitoring results are combined with the improved SVR model to predict the mining subsidence of the mining area.The main research work of the paper is as follows:(1)The study area is the Songhe mining area in the north of Panzhou City,Guizhou Province.Selected 29 scenes of Sentinel-I ascending images(2017-2018),29 scenes of Sentinel-1 descending images(2017-2018)and 7 scenes of ALOS-2 ascending images(20172018)for research monitoring of surface deformation in the area.Based on SBAS-IPTA technology,the multi-source InSAR data is processed to detect the deformation position and range in the study area,and obtain the annual average dcformation rate and time series cumulative deformation along the radar line-of-sight in the study area.The multi-source data results show that the maximum deformation rate and time series cumulative deformation in the study area are 823mm/a and 690mm/a,respectively.By consulting the data,the distribution range of Songhe coal mine and the distribution of coal mine resources in Guizhou Province are obtained.The deformation area detected by SBAS-IPTA technology is in good agreement with the distribution location of Songhe mine and coal mine resources.The cross-validation of the monitoring results of the multi-source InSAR data further confirmed the reliability of the SBAS-IPTA technology applied to the surface deformation monitoring of the Songhe mining area,and provided a data basis for the next step in the calculation of the three-dimensional surface deformation of the mining area.(2)Based on the deformation monitoring results of multi-source InSAR data,a surface deformation area with severe deformation is selected to carry out 3D surface deformation calculation.The data is resampled to establish a three-dimensional deformation solution model of the surface.The annual average deformation rate and time series cumulative deformation value of the LOS direction obtained from the multi-source data are used to obtain the annual average deformation rate and time series cumulative deformation value of the surface of the mining area in the study area in the vertical,east-west and north-south directions.The maximum deformation rates of the study area in the vertical,east-west and north-south directions are 865mm/a,107mm/a,and 604mm/a.By analyzing the monitoring results of the threedimensional surface deformation in the mining area,it is known that the deformation law of the three-dimensional deformation field obtained by the method in this paper is consistent with the mining deformation law of the mining area,that is,it conforms to the mining subsidence law.The three-dimensional surface deformation can reflect the surface deformation characteristics of the mining area more comprehensively.(3)The 32 scenes Sentinel-1 ascending images(2020-2021)covering the study area were selected,and the SBAS-InSAR technology was used to obtain the cumulative surface subsidence in time series.The 32-period subsidence data obtained by SBAS-InSAR technology was used as a sample set,combined with the improved SVR algorithm to predict the surface mining subsidence in the mining area.The experimental results show that the WOA-SVR prediction model combined with SBAS-InSAR technology has a good performance in the prediction of mining subsidence in the Songhe mining area,and the model prediction accuracy is high,which provides a reliable method for the prediction of surface subsidence in this mining area.