127 / 2021-10-01 18:59:06

Remote sensing techniques for surface deformation monitoring and risk assessment in USCB

safety pillars, deformations monitoring, remote sensing, SAR, LIDAR.

The area of the Upper Silesian Coal Basin (USCB) in Southern Poland has some of the richest coal deposits in Europe and, according to the Polish Geological Institute, may provide about 80% of the hard coal domestic consumption of Poland. The impact from extensive exploitation in the area over the safety of population and infrastructure enlarges the necessity of detailed monitoring of the surface processes triggered by the underground mining works. A comprehensive study on the surface dynamics will bring valuable inputs to the safely planning and management of the coal extraction. In the frames of the EPOS-PL+ project, funded by the European Union, several Research Infrastructure Centers are built aiming development of monitoring systems taking advantage of the modern satellite, airborne and drone (unmanned aerial vehicle - UAV) remote sensing technologies. The target is to observe the stability of two mining safety pillars as part of a Geophysical Safety System.



The first phase of the study over the test site of Marcel mine compares results from long (10 years) and short-term (3-month and 1-year) surface deformation monitoring. Comparison between digital terrain models (DTM) generated for the pillars and their surroundings from airborne and UAV-borne Light Detection and Ranging (LiDAR) data for 2011 and 2021, respectively  shows variation in the size of the subsidence. The subsidence over the pillar surfaces varies from about 0.5 to 3 meters in some zones closer to the extraction panels and reaches 4.5 m outside the pillars. On the other hand, using Differential Interferometric Synthetic Aperture Radar (DInSAR) technique the effect of the mining dynamics on the terrain changes are traced by 3-month and 1-year deformation maps. Yearly the subsidence of the terrain in the center of the subsidence bows is measured up to 1.20 meters. The short-term solutions clearly delineate the progress of the subsidence around the pillars due to the advance of the underground works and its influence on the stability in the safety area of the pillars.