Effects of Longwall Mining Subsidence on Cadastral Parcel Areas: A Case Study from the Upper Silesian Coal Basin (Poland)

Underground coal mining leads to surface subsidence and ground deformation, which may affect the accuracy of cadastral data. This study evaluates mining-induced displacement caused by longwall VIII-E-E1 extraction in seam 703/1 and examines its potential impact on the Polish EGiB cadastral register. In 2018–2021, precise GNSS observations were collected on a specially designed geodetic monitoring polygon located in the affected area. These measurements enabled a detailed assessment of surface deformation during and after exploitation. The maximum subsidence was recorded above the extracted longwall and decreased outward, forming a typical post-mining deformation basin. Although boundary-point displacements remained generally within acceptable limits, the cumulative reduction of parcel areas reached about 43 m2 in total. Five parcels (0.8% of the dataset) showed area changes exceeding 1 m2. The results indicate that a single longwall has a limited effect on cadastral data integrity; however, continued multi-panel mining may lead to progressive boundary shifts, compromising the spatial and legal reliability of cadastral resources. The study confirms the effectiveness of integrated geospatial monitoring in detecting mining-related deformation and highlights the need for continuous control of cadastral datasets, especially in the Upper Silesian Coal Basin, where large-scale mining remains active.