Tracking Deformation Processes at the Legnica Glogow Copper District (Poland) by Satellite InSAR—I: Room and Pillar Mine District

Abstract

Mining exploitation leads to slow or rapid ground subsidence resulting from deformation until the collapse of underground post-mining voids following excavation activities. Satellite SAR interferometry capabilities for the evaluation of ground movements allows the monitoring of intensive surface mine subsidence and can provide new knowledge about the risks in the mining industry. This work integrates both conventional and advanced Differential SAR Interferometry (DInSAR) to study the ground subsidence in the Legnica Glogow Copper District (LGCD, Poland) by processing about 400 Sentinel-1 images from October 2014 to April 2019. Even without field data and information on past and ongoing excavation activities, the DInSAR approach allowed us to identify 30 troughs of subsidence, ranging from 500 m to 2.5 km in diameter, which in some cases, took place several times during the analyzed time span. The cumulative subsidence in 4 years and 7 months exceeds 70 cm in several zones of the LGCD. The sub-centimetric precision achieved by advanced analysis (A-DInSAR), allowed us to monitor the real extent of the mining influence area on the surface, with deformation velocities of up to 50 mm/year. The ground deformation detected at LGCD can be due to both mining-induced tremors and roof subsidence above the underground excavation rooms. As deformations do not occur concurrently with tremors, this can be related to excavation activities or to degradation of abandoned mines.

Delineation of Backfill Mining Influence Range Based on Coal Mining Subsidence Principle and Interferometric Synthetic Aperture Radar

“…With the traditional method for monitoring surface deformation, the level gage and the global positioning system (GPS) are applied to periodically monitor the plane and elevation of the earth surface observation station above the working face to obtain the 3D deformation of the earth surface. The traditional monitoring approach has the benefits of high accuracy, but it is hard for it to meet the application needs in monitoring mining subsidence in mining areas due to the small monitoring area, high cost, large workload, and easy destruction of the observation stations [18,19]. InSAR is not only limitless with regard to weather or time, it also has the advantages of covering a wide area, high spatial and temporal resolution, and high precision.…”

A Multi-Temporal Small Baseline Interferometry Procedure Applied to Mining-Induced Deformation Monitoring

“…The Lower Silesian region, in south-western Poland, experiences intense copper mining activity operated by the KGHM company. In particular, mining activity is concentrated in the Legnica-Glogow copper district (LGCD) and has caused an impact on both the built environment and infrastructures due to ground movement of both linear and pulse-based types, triggered by underground excavations [3][4][5][6][7].…”

“…The resultant mining-induced tremors have been studied using DInSAR techniques in a previous study [3] regarding the Rudna mine. In contrast, the Legnica-Glogow copper district has been addressed in a recent couple of studies [6,7]. In particular, Antonielli et al [6] analyzed the mining-induced land subsidence and tremors using a PSInSAR approach combined with DInSAR, using Sentinel-1 data over 4.5 years (autumn 2014 to spring 2019).…”

Analysis of Mining-Induced Terrain Deformation Using Multitemporal Distributed Scatterer Sar Interferometry

“…The presence of copper mines within the AOI causes ground-surface deformations, with both a vertical component (subsidence) and horizontal component, detectable in the East-West direction. (Hejmanowski et al, 2020;Witkowski et al, 2021;Malinowska et al, 2018;Antonielli et al, 2021;Mazzanti et al, 2021). The geographical extension of the area affected by terrain deformation varies depending mainly on the depth of the excavation room, with deformation cone footprints ranging from a few hundreds of meters to kilometers.…”