Surface Deformation Monitoring In Ningdong Mining Area Based On InSAR

China is a big country of coal resources mining and consumption.Coal resources play an important role in China's energy structure.Coal mining may lead to surface deformation and then damage the ecological environment or buildings.Therefore,it is of great significance to monitor and study the direction,rate and spatial distribution of surface deformation for disaster prevention and mitigation and ecological environment management.Traditional monitoring methods such as GPS and leveling are expensive,which can not meet the requirements of surface deformation monitoring in large-scale and long-term mining.In order to study the characteristics of surface deformation in Ningdong mining area,a four-year monitoring of surface deformation over 3400 square kilometers in Ningdong mining area is carried out based on time series InSAR technology.The information of ascending and descending orbit deformation and two-dimensional deformation vector field are obtained by stacking technology,and the results of surface deformation obtained by IPTA technology are compared and analyzed.The two are consistent in deformation characteristics.The main research results are as follows(1)Using Stacking technology to process 222 ascending and descending track sentinel data in Ningdong mining area from 2017 to 2020,the average deformation rate and cumulative deformation displacement in the study period are obtained.The results show that the maximum settlement in the mining area is more than 400 mm.The vector displacement field of Ningdong mining area is calculated by combining the ascending and descending orbit data,and the average deformation rate in the east-west and vertical directions of the study area is obtained.The results show that there are several obvious settlement concentration areas in this area,and the East-West deformation is often greater than the vertical deformation in the settlement area.(2)IPTA technology is used to select the interference points and calculate the deformation rate of the data in the study area,and the deformation rate and cumulative deformation variable of the interference points in the area are obtained.Compared with the results of Stacking technology,the two methods have good consistency in deformation trend,and the closer to the deformation center,the greater the deformation rate.In addition,in some areas that can not be monitored by IPTA technology,the deformation rate is often greater than 80 mm/a,which leads to the incoherence of the interference points and the failure to obtain effective results.