Monitoring And Analysis Of Land Subsidence Of Jiaozuo Based On SBAS-InSAR

Surface subsidence is a kind of geological disaster caused by natural or man-made factors.It can have a continuous and irreversible impact and cause great harm to human production and life.Jiaozuo,Henan Province is a city rich in coal and other mineral resources.Long-term large-scale underground coal mining activities have damaged the endurance of the strata around the mining area and caused ground collapse around the mining area.On the other hand,as an industrial city,Jiaozuo requires a large amount of groundwater resources for the operation of factories,which has caused a drop in groundwater level and aggravated land subsidence.Therefore,ground subsidence monitoring in Jiaozuo is of great significance for subsidence prevention and disaster warning.Traditional land subsidence monitoring mainly includes leveling and GNSS monitoring technologies,but these two methods are not efficient in large-area,long-term,continuous land subsidence monitoring.The InSAR technology developed in recent years can realize large-area,high-precision ground deformation monitoring and has become the main monitoring technology at present.Therefore,this paper is based on the small baseline subset interferometry(small baseline subset InSAR)technology and uses 37 Sentinel-1A image data to extract long-term and continuous ground deformation information from January 2018 to May 2020 in Jiaozuo area.Finally,the characteristic analysis of the SBAS-InSAR deformation monitoring results is carried out,and the driving factors of the ground deformation in the study area are analyzed from the two aspects of stratum conditions and ground engineering disturbance.The main conclusions are as follows:(1)Analyzing the deformation characteristics of the study area,it is found that during the period from January 2018 to May 2020,the annual subsidence rate in Jiaozuo area varies from-40mm/yr to 10mm/yr.On the whole,the surface deformation of the central city was stable,and the cumulative deformation was normal Within the scope;the western area(industrial park)has overall subsidence,but the amount of subsidence is relatively small,with an annual subsidence rate of 1mm/yr?-10mm/yr;the southern area also has overall subsidence,accompanied by a funnel phenomenon;while the eastern area has ground uplift The coexistence of settlement.In addition,a total of three large funnel areas are formed in the study area,mainly located in the east and southeast of the study area,and only sporadic settlement centers appear in other areas.Among them,the largest settlement area is near the railway station of Daiwang Town,Macun District,and the maximum annual settlement rate can reach-40mm/yr.(2)Using the leveling data of the same period to verify the accuracy of the SBAS-InSAR deformation monitoring results from the two perspectives of the error and the correlation coefficient,the results show that the two are in good agreement.(3)The driving factors of the monitored deformation variables are analyzed.The following conclusions are drawn: the ground deformation in the eastern part of Jiaozuo area is caused by many aspects,such as: the two subsidence areas formed in the eastern part of the study area are both close to the surrounding area.The Yanmazhuang Coal Mine and the Zheng-Tai Passenger Dedicated Line,coupled with the massive extraction of groundwater by factories in the two subsidence areas in the east,have jointly led to the formation of subsidence areas.The overall settlement of the western industrial zone is due to the decrease of groundwater level caused by the mining of groundwater by the factory,which reduces the bearing capacity of the ground,which leads to the overall settlement of the ground.However,there is neither a mining area nor a large ground load in this area,so the settlement is not large.