Anna Buczyńska

The bilateral UNESCO Geopark Muskau Arch, located on the German-Polish border is characterized by a unique glaciotectonic post-mining landscape where most evidence of former industrial activity has been removed or concealed due to man-made and natural revitalization processes. This paper presents a strategy and pilot works for digitally reconstructing and presenting the forgotten mining heritage of the geopark using advanced geospatial and geovisualisation technologies such as 3D point cloud based modelling, Augmented Reality (AR) tools and proprietary generative Artificial Intelligence algorithms. The project, developed under the Poland-Saxony INTERREG 2021–2027 programme, integrates archival materials with field-acquired data to produce accurate 3D models of key heritage objects, including underground mining workings, shaft heads, transport infrastructure, and industrial buildings. These digital reconstructions including textures and descriptive information will be used to present in an attractive and interactive ways including augmented reality mobile application, virtual tours with 360 degree panoramas and will be embedded within a geoportal featuring interactive maps. Preliminary results of reconstructing selected mining objects demonstrate the feasibility of combining photogrammetric surveys, laser scanning, archival photographs, plans, and historical mining maps to create hybrid 3D models that accurately represent the character and dimensions of vanished structures, supporting heritage education and preservation for diverse user groups such as tourists, pupils, and local community.

Ground displacement monitoring is a key aspect of assessing the impacts of underground gas storage (UGS). Conventional approaches are based on geodetic methods that, while providing high accuracy, are limited in spatial coverage and temporal resolution. This study assesses the suitability of synthetic aperture radar interferometry (InSAR) as a complement to standard ground displacement monitoring and identifies a method with sufficient accuracy to assess ground displacement conditions and facility safety. A comparative analysis was conducted using European Ground Motion Service (EGMS) data and independently derived Sentinel-1-based time series generated with the small baseline subset (SBAS) and persistent scatterer InSAR (PSI) methods. The analysis of a cavern UGS facility located in northern Poland spanned a five-year period from 2019 to 2023 and included error analysis and significance testing of differences between the methods. Observed displacement rates across the study area ranged from −4.3 mm/year for the SBAS method to −0.4 mm/year for PSI. Although the absolute values of the estimated velocities differed among the methods, the differences between the modeled deformation rates were statistically insignificant. The results confirm that InSAR can supplement geodetic monitoring and help investigate seasonal ground deformations associated with gas injection and withdrawal cycles as well as environmental processes, capturing patterns that discrete geodetic measurements may miss.

^{Mining activities lead to significant transformations of the original terrain, resulting in development of new post-mining landscape.} The objective of this study was to assess the land transformations in the result of prolonged, underground and open-pit mining of shallow brown coal deposits in glaciotectonic structure of Muskau-Arch on the Polish-German border in the context of the geoheritage of this area. With this purpose, a geodatabase of thematic datasets representing progress of mining was developed in a geographic information system (GIS) based on topographical maps, mining plans, photographs, and digital elevation models (DEMs). The following timescales: 1903, 1911, 1937, 1955, 1972 and present-day were digitally reconstructed and quantitatively analysed using spatial processing functions including feature layer overlay and DEM differencing. The original, transitional and present-day landscapes were compared and visualised on five thematic maps and tables describing the spatio-temporal transformation of the natural landscape caused by underground and open-pit mining. Approximately 36.85% of the study area has been transformed, giving rise to the landscape of the present-day Geopark. The results provide insight into the genesis of its geoheritage. The adopted methodology, based on the historical GIS (HGIS) approach, can be applied to other post-mining sites, providing relevant documentation is available.

Underground gas storage (UGS) facilities may cause ground displacements as a result of the cavern convergence or regular gas injection (alternate ground uplift and subsidence). The occurrence and scale of displacements are strongly dependent on the storage time and cavern capacity. At an early stage of facility operation, displacements can be difficult to detect in the presence of wetlands. The main objective of this study was to describe the global and local relationships between vertical ground displacements observed over a small and relatively new Kosakowo UGS facility (Poland) from 2014 to 2024 (dependent variable) and selected topographic, hydrological, and mining factors (independent variables). The dependent variable was determined through SBAS-InSAR analysis of Sentinel-1 SAR data, while the independent variables were developed using passive Sentinel-2 imagery and open geospatial data. The global relationships between variables were described using Ordinary Least Squares (OLS) and Generalized Linear Regression (GLR) models, while the Geographically Weighted Regression (GWR) model was utilized to analyze local relations. The results obtained indicate that ground displacements were characterized by seasonal fluctuations between 4 mm and 10 mm. The factors that had, both globally and locally, the strongest influence were soil moisture, vegetation water content, and the flora condition, indicating that the environmental hydrogeology had the greatest impact on the phenomenon under study. None of the considered models identified underground gas storage as a significant contributing factor to the observed ground displacements. The results confirm that the presence of wetlands can be a significant obstacle to an accurate description of the impact of gas storage on the ground movements, especially in UGS areas at an early stage of operation.

Despite successful land reclamation efforts, post-mining areas are still prone to secondary effects of mineral extraction. These effects include surface deformations, damage to infrastructure and buildings, and periodic or permanent changes to surface water resources. This study focused on analyzing a former copper mine in southwest Poland in terms of surface water changes, which may be caused by the restoration of groundwater conditions in the region after mine closure. The main objective of the study was to detect areas with statistically significant changes in surface water between 2015 and 2024, as well as to identify the main factors influencing the observed changes. The methodology integrated open remote sensing datasets from Landsat and Sentinel-1 missions for deriving spectral indices—Modified Normalized Difference Water Index (MNDWI) and Normalized Difference Moisture Index (NDMI), as well as Surface Soil Moisture index (SSM); spatial statistics methods, including Emerging Hot Spot analysis; and regression models—Random Forest Regression (RFR) and Geographically Weighted Regression (GWR). The results obtained indicated a general increase in vegetation water content, a reduction in the extent of surface water, and minor soil moisture changes during the analyzed period. The Emerging Hot Spot analysis revealed a number of new hot spots, indicating regions with statistically significant increases in surface water content in the study area. Out of the investigated regression models, global regression (RFR) outperformed local (GWR) models, with R2 ranging between 74.7% and 87.3% for the studied dependent variables. The most important factors in terms of influence were the distance from groundwater wells, surface topography, vegetation conditions and distance from active mining areas, while surface geology conditions and permeability had the least importance in the regression models. Overall, this study offers a comprehensive framework for integrating multi-source data to support the analysis of environmental changes in post-mining regions.

Nowadays, satellite remote sensing produces vast amounts of Earth observation data, but without appropriate processing, visualization and interpretation, they are of limited use for a regular user. Web map applications are one of the approaches to share the data online. They allow not only for visualization, but also for analysis and interaction with geographic data. Such web services are used for a variety of purposes, fulfilling informational and educational roles. The SARforMINE is a geoportal service for monitoring, analysis and visualisations of predictive modelling of environmental impacts above underground gas storage facilities. The designed web map application represents information on selected environmental components, ground movements and vegetation condition derived from open-access satellite imagery, SAR and optical respectively. Additionally, historical data are analysed using machine learning for the purpose of predictive modelling of the potential future changes. The proposed approach outlines how web GIS services can augment traditional monitoring of underground gas storage sites.

The motivation for this study arises from the need to monitor the condition of a rehabilitated post-mining areas even decades after the end of the recovery phase. This can be facilitated with satellite derived spectral vegetation indices and Geographic Information System (GIS) based spatiotemporal analysis. The study area described in this work is located in Western Poland and has unique characteristics, as it was subjected to the combined underground and open pit mining of lignite deposits that had been shaped by glaciotectonic processes. The mining ended in early 1970’ties and the area was subjected to reclamation procedures that ended in the 1980’ties. We used the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) spectral indices derived from Sentinel-2 data for the 2015–2022. period. Then, we applied a combination of GIS-based map algebra statistics (local, zonal and combinatorial) and GI* spatial statistics (hot spot and temporal hot spot) for a complex analysis and assessment of the vegetation cover condition in a post-mining area thought to be in the rehabilitated phase. The mean values of NDVI and EVI for the post-mining study area range from 0.48 to 0.64 and 0.24 to 0.31 and are stable in the analyzed 8 year period. This indicates general good condition of the vegetation and post-recovery phase of the area of interest. However, the combination of spatiotemporal analysis allowed us to identify statistically significant clusters of higher and lower values of the vegetation indices and change of vegetation cover classes on 3% of the study area. These clusters signify the occurrence of local processes such as, the encroachment of aquatic vegetation in waterlogged subsidence basins, and growth of low vegetation in old pits filled with waste material, barren earth zones on external waste dumps, as well as present-day forest management activities. We have confirmed that significant vegetation changes related to former mining occur even five decades later. Furthermore, we identified clusters of the highest values that are associated with zones of older, healthy forest and deciduous tree species. The results confirmed applicability of Sentinel-2 derived vegetation indices for studies of post-mining environment and for the detection of local phenomena related to natural landscaping processes still taking place in the study area. The methodology adopted for this study consisting of a combination of GIS-based data mining methods can be used in combination or separately in other areas of interest, as well as aid their sustainable management.

The vegetation of the post-mining areas is subject to constant and significant changes. Reclamation works, carried out after the cessation of mineral extraction, contribute to the intensive development of new plant species. However, secondary deformations, occurring even many years after the end of exploitation, may cause the degradation of the vegetation cover. It is, therefore, an important issue to identify changes in flora conditions and to determine whether and to what extent past mining has a negative impact on the plant cover state. The objectives of this research have been as follows: (1) analysis of the flora condition in the post-mining area in the 1989–2019 period, (2) identification of sites with significant changes in vegetation state, and (3) modeling of the relationship between the identified changes in vegetation and former mining activities. The research was carried out in the area of the former opencast and underground lignite mine “Friendship of Nations—Babina Shaft,” which is located in the present-day Geopark (Western Poland), using Landsat TM/ETM+/OLI derived vegetation indices (NDVI, NDII, MTVI2) and GIS-based spatial regression. The results indicate a general improvement in flora condition, especially in the vicinity of post-mining waste heaps and former opencast excavations, with the exception of the northwestern part of the former mining field where the values of all of the analyzed vegetation indices have decreased. Also, four zones of statistically significant changes in the flora condition were identified. Finally, the developed GWR models demonstrate that former mining activities had a significant influence on changes in the plant cover state of the analyzed region.

The lignite mine called 'Friendship of Nations - Babina Shaft', located on the border between Poland and Germany, was closed almost 50 years ago. Despite the cessation of mining works (carried out by opencast and underground methods) and carrying out reclamation process, the negative effects of the former mineral exploitation are still observed in this region (e.g. sinkholes, local flooding, subsidence). It should be emphasized that the area of ​​the currently closed mine is also characterized by a complicated glaciotectonic structure, which is the result of successive glacial periods in the past. Both factors, i.e., the past mining activity and geological conditions, may affect the condition of soils and vegetation of the analysed area. The aim of this study was to determine, whether and to what extent the former lignite mining and the complicated glaciotectonic structure had an impact on the changes in the state of plant cover and soils, noted in the period of 1989-2019. A new index, Mining and Geology Impact Factor (MaGIF), was developed to describe the strength and the nature of the relationship between the aforementioned factors within four test fields, based on coefficients’ values and variables of six Ordinary Least Squares (OLS) models. In the research 12 independent variables, representing geological and mining conditions of the area, were prepared. The dependent variables, statistics of selected spectral indices obtained for 1989-2019, were determined in the GIS environment, within individual pixels of the research area. In this study, two vegetation indices (NDVI and NDII) and four soil indices (DSI, SMI, Ferrous Minerals and SI3), calculated on the basis of Landsat TM/ETM +/OLI images, were used. The values of the obtained MaGIF index were ​​in the range of -9.99 - 0.62, and their distribution in the test fields proved that the former mining and geological conditions had the strongest impact on the vegetation and soils of the central part of field no. 1, as well as on north-western and south-eastern parts of field no. 4. The nature of the influence of explanatory factors on the indicated components of the environment was negative (an increase or decrease in the value of the independent variable correlated with a decrease or increase in the value of a given spectral index, respectively). In the western and southern parts of field no. 1, eastern part of field no. 3, central and eastern parts of field no. 4, as well as in a major part of field no. 2, the influence of explanatory factors was the smallest. Only in fields no. 2 and 4, the small zones of positive impact of the independent variables were observed. The results indicate that the former mining and geological conditions have a significant influence on the condition of the vegetation and soils of post-mining areas. Therefore, it is extremely important to monitor the changes taking place in these regions in order to undertake appropriate preventive works and eliminate the resulting damage.