Ground subsidence associated with mining activity in the Ningdong coal base area, northwestern China revealed by InSAR time series analysis

Ningdong coal base area located in northwestern China is one of the largest coal-producing bases China. The aim this work to investigate a regional-scale mining subsidence over area, by using both conventional and advanced Differential Synthetic Aperture Radar Interferometry (DInSAR) methods. Fifteen L-band SAR images from ALOS-2 satellite 102 C-band Sentinel-1A spanning between November 2014 July 2019 were used for analysis. To increase spatial extent displacement signal because decorrelated effects, we modified traditional Small Baseline Subset (SBAS) method incorporate coherence into inverse problem, hereafter call it coherence-based SBAS method. Instead excluding pixels present interferograms, keep all time series analysis down-weighted with coherence. We performed two datasets obtain rate maps time-series areas, compared results that stacking InSAR evaluated effectiveness DInSAR monitoring comparing differential interferograms displacements derived data. Compared C-band, are less affected phase aliasing due large gradients. most significant was found at Maliantai mine −264 mm/year detected Sentinel-1 validated accuracy 18 GPS stations above five active regions. average RMSE measurements 28.4 mm data 21 Our demonstrate combined exploitation through methods could be crucial monitor ground which provides insights dynamics determine characteristic surface response longwall advance.