Analysis of surface subsidence in Shuixigou sealed fire area by using D-InSAR technology

In order to master the change law of surface subsidence in Shuixigou sealed fire area of Zhunnan Coalfield, the Sentinel-1 data from October 2014 to October 2015 were processed by differential interferometry method, and 11 sets of interferograms, differential interferograms, deplaning effect maps, unwrapping effect maps, and ground deformation maps were obtained.Comparing and analyzing the subsidence distribution images in 2014 and 2015, it shows that the subsidence range caused by underground coal fire in the study fire area is roughly the same, and the subsidence value shows similar regular changes. Combining remote sensing technology to accept or reject the sealed fire area determined by the abnormal pixels of temperature and vegetation, five more precise fissure positions A, B, C, D and E are delineated, and the five positions have different changes in subsidence values.Among them, the maximum value of surface subsidence of A, B, and C decreases with time, and the maximum value of surface subsidence of D and E increases first and then decreases; the change in subsidence of C has the smallest change and is relatively stable. The application shows that it is feasible and accurate to use differential interferometry to monitor the ground surface subsidence in underground coal fire combustion areas.