Identification And Monitoring Of Geological Hazards In Mining Area Based On InSAR Technology

InSAR is a new type of earth observation technology,which has been rapidly developed and improved in recent years.With the ability to quickly and accurately obtain small deformations on the ground,it is widely used in landslides,collapses,earthquakes etc.Mineral mining destroys the original stress balance of the stratum,causing deformations such as subsidence,cracking,compression,etc.Which may induce geological disasters such as collapse and landslide,threaten the production and life of local residents,and hinder economic development.The identification of geological hazards in mining area is helpful to prevent and control disasters and maintain the sustainable development of mining area.According to the different advantages of multi-source InSAR Data,this paper uses D-InSAR and temporal InSAR technology to obtain the surface deformation information of Miyi County in Panzhihua City from different scales,and puts forward a disaster identification method based on the surface deformation information,combined with the characteristics of topography and remote sensing interpretation signs.The stability of Dalongtang landslide is analyzed by limit equilibrium method.Combined with the results of stability analysis,the deformation monitoring of Dalongtang landslide is carried out by using the method of lifting rail combination,and the dynamic deformation characteristics of landslide in time and space and the relationship between rainfall and landslide deformation are analyzed,so as to provide scientific basis for the prevention and treatment of landslide.The main research results are as follows:1.Using the combination of D-InSAR and time series InSAR technology,the surface deformation of Miyi County is monitored by using ALOS-2 and Sentinel-1A data,and the results of surface deformation in Miyi County and time series deformation in Baima mining area in 2018 are obtained,which verifies the advantages of the combination of the two technologies.The combination of the two technologies improves the acquisition rate of surface deformation information,and provides a reference for rapid development,It provides a means to identify geological disasters accurately.2.According to the extracted surface deformation results,combined with remote sensing interpretation signs and field surveys,43 geological hazards were finally delineated in the Baima mining area,including 34 landslides,6 unstable slopes and 3 land subsidence.The analysis of time series deformation curve shows that the appearance of continuous rainfall leads to the obvious change of surface deformation,which proves that rainfall is one of the inducing factors of surface deformation.3.Taking the Dalongtang landslide in Miyi County as the research object,the basic characteristics and deformation mode of Dalongtang landslide are qualitatively analyzed through field investigation,and then the stability of the landslide is analyzed by using the limit equilibrium method.It is concluded that the Dalongtang landslide is in an unstable state under the influence of inducing factors.4.The surface deformation characteristics of Dalongtang landslide are studied based on the data of ascending and descending tracks.Based on the comprehensive analysis of the vertical and sliding deformation rate results and the time series deformation process results,it is found that the surface deformation distribution range and deformation rate change law of the landslide area in different periods are obvious.The deformation of Dalongtang landslide presents obvious correlation with rainfall.During the monitoring period from January 2019 to October 2020,the June 2019 landslide can be distinguished according to the deformation characteristics.The severe deformation in October and July to October 2020 is related to the continuous heavy rainfall in the study area.