Fine Mapping of Surface Deformation in Xinjing Open-Pit Mine,Inner Mongolia Using FS-InSAR Technique

Objectives On February 22, 2023, a large area of slope collapsed in Xinjing Open-Pit Mine, Inner Mongolia Autonomous Region, China. In order to prevent this kind of disaster scientifically, it is necessary to carry out fine monitoring of slope stability in large open-pit mine, so as to obtain the temporal and spatial characteristics of slope deformation comprehensively, and take corresponding prevention measures.

Methods The full scatterer interferometric synthetic aperture radar (FS-InSAR) technique was applied for detailed monitoring of Xinjing Open-Pit Mine, with 24 Sentinel-1 synthetic aperture radar images acquired from September 9, 2021 to August 11, 2022. Fine ground deformation of Xinjing Open-Pit Mine was obtained, and the temporal and spatial distribution characteristics of the deformation were analyzed.

Results For the low-coherence open-pit area, the FS-InSAR technique can obtain fine surface deformation with a density of 4 758 points per km². The deformation anomaly signal of bottom acceleration had appeared since February 2022, before the collapse occurred. The deformation at the bottom of the west side of the south slope is the most serious, with deformation rate more than 200 mm/a, and there is a collapse risk.

Conclusions The FS-InSAR technique can fully retrieve the spatial-temporal distribution of slope deformation before collapse disaster in open-pit mines, which is of great significance for mine safety production in the future.