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

Benedetta Antonielli,Stefano Scancella,Paolo Mazzanti,Francesca Bozzano,Alessandra Sciortino

doi:10.3390/land10060653

Benedetta Antonielli, Stefano Scancella + Show 3 more

Open Access

https://doi.org/10.3390/land10060653

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Journal: Land	Publication Date: Jun 18, 2021
Citations: 12	License type: CC BY 4.0

Affiliation: Sapienza University of Rome, University of L'Aquila

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.

Highlights

As an active mining district, the Legnica Glogow Copper District (LGCD, Poland) represents a dynamic environment that evolves very quickly in time, following the ore exploitation activities in the room-and-pillar mines
The Advanced Differential Synthetic Aperture Radar (SAR) Interferometry (A-DInSAR) approach consists of the combination of information from a large number of SAR images, allowing us to derive the temporal evolution of displacements of objects on the ground during the investigated period
The velocity maps obtained by the A-DInSAR approach (Figure 3a,b) highlight the presence of some widespread deformations above the room and pillar mines of the LLeeggnnica-‐Głogow Copper District (LGCD), showing a complex and discontinuous pattern in space

Summary

Introduction

As an active mining district, the Legnica Glogow Copper District (LGCD, Poland) represents a dynamic environment that evolves very quickly in time, following the ore exploitation activities in the room-and-pillar mines. InSAR has gained more and more utilization in mines monitoring, providing ground deformation measurements with sub centimeter accuracy [4,5,6,7,8]. This technique is very effective for structural health monitoring purposes involving structures like dams (e.g., [9,10,11] and Cultural Heritage degradation (e.g., [12])). Advanced Differential SAR Interferometry (A-DInSAR) can provide information about the ongoing and past deformations with millimeter accuracy and can be used for many different applications in the field of engineering geology, e.g., subsidence and settlements [13,14], landslides (e.g., [15,16]), glaciers, and dynamics of permafrost [17,18]

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