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Despite the long tradition of mining activities in Kosovo, there is still the a lack of policies for post-mining. Specifically, focusing on coal mining, this research analyzes the sustainable transition and post-mining management in the Ruhr Region, exploring the potential for knowledge transfer to enhance mining practices in Kosovo. The research aims to identify transferable strategies for sustainable mining transitions by examining environmental, social, and economic dimensions. Through comparative analysis, the study assesses the applicability of Ruhr’s experiences in fostering environmentally responsible mining practices in Kosovo and beyond. Similarities and possible challenges are discussed based on the environmental and socio-economic points of view. The findings contribute insights into effective post-mining strategies, facilitating knowledge transfer to regions undergoing similar transitions and thereby fostering sustainable mining practices globally.

Direct and indirect effects after mine operations cease operating must ideally be subjected to perpetual monitoring routines in order to detect possible risks or avoid adverse effects on the surrounding ecosystems at an early stage. In this contribution, mining subsidence lakes created inside the nature reserve Kirchheller Heide and Hilsfeld Forest are subjected to analysis for a long-term monitoring scheme. For this purpose, we employ high-resolution unmanned aerial system (UAS)-based multispectral and thermal mapping tools to provide a fast, non-invasive and multitemporal environmental monitoring method. Specifically, we propose to monitor vegetation evolution through multispectral analysis, biotypes identification using machine learning algorithms, and water surface extent detection, together with their thermal behavior. The aim of this contribution is to present the proposed workflow and first results to establish a baseline for future analyses and subsequent surveys for long-term multi-temporal monitoring. [ABSTRACT FROM AUTHOR]

Direct and indirect effects after mine operations cease operating must ideally be subjected to perpetual monitoring routines in order to detect possible risks or avoid adverse effects on the surrounding ecosystems at an early stage. In this contribution, mining subsidence lakes created inside the nature reserve Kirchheller Heide and Hilsfeld Forest are subjected to analysis for a long-term monitoring scheme. For this purpose, we employ high-resolution unmanned aerial system (UAS)-based multispectral and thermal mapping tools to provide a fast, non-invasive and multitemporal environmental monitoring method. Specifically, we propose to monitor vegetation evolution through multispectral analysis, biotypes identification using machine learning algorithms, and water surface extent detection, together with their thermal behavior. The aim of this contribution is to present the proposed workflow and first results to establish a baseline for future analyses and subsequent surveys for long-term multi-temporal monitoring.

Forestry reclamation practices have been very popular in the second half of the last century, and many spoil heaps have been converted into forests since. In our experiment, three forest reclamations of different ages (~90, ~50, and ~30 years) and three soil vegetation covers (I—maple and cherry, II—maple, and III—alder) from Sokolov, Czech Republic, were investigated. In each of the three stands, two soil profiles have been dug, and both disturbed and undisturbed soil samples were taken from all recognized horizons. Samples were tested for bulk and particle density, porosity, water retention capacity, pH (H2O, KCl), cation exchange capacity, oxidizable carbon content, organic matter quality, plant available nutrients, and risk elements. A comparison of these properties throughout the profile, as well as between the stands, was presented. A significant role of stand age in soil profile development and soil quality was observed, as well as the tendency of the anthropogenic mine Technosol to evolve into a forest Cambisol in this climate region and parent material. Influence of forest vegetation cover was observed to ameliorate soil properties by accumulating organic matter, thus reducing compaction and increasing CEC and nutrient availability. [ABSTRACT FROM AUTHOR]

The chemical composition of mine water discharged from flooded underground mines typically improves over time. This phenomenon is called first flush and can be described by a characteristic curve. Shortly after the mine water begins to discharge, water constituent concentrations rise and then fall in an almost exponential curve, improving water quality over time. In this study, the change in mine water quality was investigated throughout the mine water body. This mine water body commonly consists of different water bodies with individual densities, resulting in mine water stratification. Anthropogenic disturbance of the mine water body can disrupt this stratification and also the positive effect of the first flush. To better understand and predict the first flush, the first flush was simulated experimentally using an analogue model of a flooded underground mine, the Agricola Model Mine. The results were compared with field studies to help understanding and predicting the change in mine water quality. Overall, the results suggest that the first flush occurs throughout the mine water body, making it similar to a chemical reactor. This better understanding of the process can lead to more effective mine water management and design of mine water treatment facilities. [ABSTRACT FROM AUTHOR]

The mineland rehabilitation can be a challenge due to high soil density and low levels of organic matter and nutrients. This study assessed soil chemical attributes and leaf nutritional contents of two native species (Mimosa acutistipula var. ferrea and Vismia baccifera) grown in an iron waste pile under environmental rehabilitation in the Carajás Mineral Province, Eastern Amazon, Brazil. Soil samples were collected close to plant species in three different chronosequences of rehabilitation. Regardless of the rehabilitation stage, the soils have low levels of phosphorus, potassium, calcium, magnesium, and boron. A tendency of organic matter accumulation was observed at the advanced stage (5–8 years after the onset of rehabilitation process) and it was correlated with other soil nutrients. The leaf nutrient' contents of M. acutistipula and V. baccifera tend to be distinct from each other, which could indicate that the studied species have different nutritional requirements. The V. baccifera presented higher leaf concentrations of sulfur, copper, and zinc, while M. acutistipula stood out for presenting a higher leaf nitrogen content, which is possibly related to its nitrogen-fixing capacity. In general, an improvement of soil chemical attributes was achieved with the advance of the rehabilitation stages, showing the efficiency of the procedures performed to rehabilitate the studied areas. [ABSTRACT FROM AUTHOR]

Both biotic and abiotic natural resources are the capital of the biosphere that may be exploited to meet human needs and promote human welfare. Global warming is a consequence of increasing environmental degradation. During photosynthesis, trees may collect carbon from the atmosphere, separate carbon from oxygen, and release oxygen back into the atmosphere. This investigation was conducted on post-coal mining reclamation land that PT. Bukit Asam (BA) restored in 2009, 2012, and 2015. This study employs a quantitative approach with a purposive sampling methodology. The utilized sampling intensities were 1%, 2.5%, and 5%. The plot chosen is a 20-by-20-meter rectangle. Carbon storage for the 2009 planting time averaged 40.57 tons per hectare over a total area of 32.89 ha. Carbon storage for the planting year of 2012 with a total area of 5.73 hectares and an average carbon storage of 26.37 tons per hectare. Carbon sequestration in 2015 with a total area of 3.90 hectares and an average carbon storage of 20.86 tons per hectare.

On post-mining soils, revegetation efforts are very difficult; only 49.74 percent of local plants survive. A native plant species called Shorea parvifolia dominates in the original forest of the study site at PT ABB. The strategy to improve the quality of post-mining soil as a planting medium for Shorea parvifolia seeds is the use of biochar as an ameliorant. This study aims to analyze the Success Rate of Biochar and Cow Manure on the Revegetation Success of Shorea Parvifolia Plants in Postmining Land. A completely randomized design (RBD) approach was used in this study to determine the percentage of biochar and manure that would survive and be suitable as soil planting media on post-mining land and in the natural habitat of Shorea parvifolia. The research was conducted in PT ABB's nursery and studied five levels of post-mining soil treatment, manure and biochar mixture, namely (B1) 90%+10%+0%; (B2) 80%+15%+5%; (B3) 70%+20%+10%; (B4) 60%+25%+15%; and (B5) 50%+30%+20%, with untreated post-mining soil (B0) and forest soil from Shorea parvifolia habitat as controls (B0+). In the study unit, 97.3% of the seeds survived. The growth of seedling stem diameter at treatment level B2 is a research variable that is significantly different from the control (B0) with a p value of 0.005, but not significantly different from other growth variables.

The theory of Professor Stanislaw Knothe, known as Knothe's Theory, has been the foundation for practical predictive calculations of the impacts of exploitation for many years. It has enabled the large-scale extraction of coal, salt and metal ores located in the protective pillars of cities and prime surface structures. Knothe's Theory has been successfully applied in Polish and global mining for over seventy years, making it one of the most well-known and recognized achievements in Polish mining science. Knothe's Theory provides a temporal-spatial description of subsidence that relies on four essential parameters: the vertical scale parameter a, the horizontal displacement parameter λ, the horizontal range scale parameter cotβ and the time scale parameter c. This article characterizes the parameters of Knothe's Theory used in various current applications for calculating subsidence, surface and rock uplift, and other applications of the theory, even beyond its classical form. The presented solutions are based on a mathematical model of the interaction of a complex element and cover topics such as subsidence during full exploitation with roof collapse and full exploitation with backfilling, pillar-room mining, the effect of salt caverns on the surface and salt rock, and fluid deposits and surface uplift caused by changes in the water level within closed coal mines. The article also discusses the evolution of the range angle of the main influences and presents Knothe's solutions related to time, describing the horizontal displacement parameter λ. [ABSTRACT FROM AUTHOR]

The problem of sustainability of energy production in the context of the expansion of renewable energy cannot be solved without a deep technological modernization of the fossil fuels extraction in line with Industry 4.0. Along with this, the expected transition to the human-centric Industry 5.0 raises the question for researchers: what core technologies of the Mining 4.0 platform will determine its transformation into Mining 5.0 in order to meet the imperative of sustainable development and the dominance of green energy. This review presents a multifaceted overview of Mining 4.0 core technologies, derived from Industry 4.0, such as smart sensors, neural networks, Big Data analytics, Internet of Things, digital twins and artificial intelligence, that form cyber-physical systems for high-performance and complete extraction of fossil energy sources. The review of works in the field of transition to Industry 5.0 is associated with Mining 5.0 core technologies—Cloud Mining, post-mining, biochemical extraction of minerals and production of green hydrogen fuel from fossil hydrocarbons, which is expected after 2050. A conclusion is made about the need for a deep analysis of harmonizing the possibilities for the innovative development of fossil fuel sources and renewable energy for sustainable energy production in the upcoming decades. [ABSTRACT FROM AUTHOR]

Forestry reclamation practices have been very popular in the second half of the last century, and many spoil heaps have been converted into forests since. In our experiment, three forest reclamations of different ages (~90, ~50, and ~30 years) and three soil vegetation covers (I—maple and cherry, II—maple, and III—alder) from Sokolov, Czech Republic, were investigated. In each of the three stands, two soil profiles have been dug, and both disturbed and undisturbed soil samples were taken from all recognized horizons. Samples were tested for bulk and particle density, porosity, water retention capacity, pH (H2O, KCl), cation exchange capacity, oxidizable carbon content, organic matter quality, plant available nutrients, and risk elements. A comparison of these properties throughout the profile, as well as between the stands, was presented. A significant role of stand age in soil profile development and soil quality was observed, as well as the tendency of the anthropogenic mine Technosol to evolve into a forest Cambisol in this climate region and parent material. Influence of forest vegetation cover was observed to ameliorate soil properties by accumulating organic matter, thus reducing compaction and increasing CEC and nutrient availability.

This article aims to make a diagnosis of the current situation of mine closure in Colombia, to transfer the knowledge and experience lived by Germany in this aspect, to identify the regulations that have been established in the country to date concerning to mine closure, the challenges faced by the country, the initiatives and possible solutions that the country has carried out at present to ensure proper closure exposing success stories and finally concludes the needs, those responsible and how to address this relevant and critical issue for the country. [ABSTRACT FROM AUTHOR]

In an Afrotropical region experiencing massive deforestation, restoration approaches should provide sustainable solutions for recovering biodiversity. Arthropods are a sensitive taxonomic group for habitat alteration by deforestation and can be good indicators for restoration studies. Ground-dwelling arthropods provide important ecosystem functions, such as predation or organic matter decomposition, thereby contributing to ecosystem functionality. The consequences of post-mining management on arthropods in the Afrotropical region remain understudied. We carried out a comprehensive sampling of ground-dwelling arthropods in the dry and wet seasons across four land-use types in the semi-deciduous forest zone of Ghana. We then analysed whether the specific tree communities, vegetation structure and seasonal differences affected arthropod communities in the restored post-mining forest compared to the dominant alternative land-use type (agroforestry plantation), a natural reference (natural forest) or an unmanaged former mining area (gravel mine). In total, 43,364 arthropods were sampled and assigned to 78 taxonomic groups representing 14 order/sub-order, 28 beetle families, 25 spider families, 5 hunting guilds of spiders and 6 trophic groups of beetles. Overall, Araneae, Coleoptera, Hymenoptera and Orthoptera all had higher activity densities in the wet season. The vegetation structure of the three land-use types with trees supported a greater overall activity density of arthropods and a more diverse functional composition compared to the unmanaged gravel site. Pronounced variation between the dry and wet seasons further influenced the taxonomic and functional composition. The active forest restoration of this post-mining area is a promising approach to drive arthropod communities towards a comparable state observed in the natural forest. [ABSTRACT FROM AUTHOR]

The sustainable transformation of surface coal mines aims to recover geoenvironmental and socioeconomic factors (ecosystems, landscape, soil, water, employment, etc.) related to extractive operations. The transition to sustainability starts when a mine enters the ageing/closing phase and includes large-scale technical activities for repurposing the mined sites. Moreover, circular economy practices and methods are introduced for efficient and socio-environmentally friendly use of mining wastes and non-exploited resources. The selection of a strategy for the sustainable transformation of a mine constitutes a complex decision-making framework presenting various practical problems. This paper provides a critical analysis concerning the definition of the transformation problems and suggests a decision-making methodology for the selection of a strategy for sustainability with a case study of a closing surface lignite mine in Greece. The methodology combines (a) a strengths–weaknesses–opportunities–threats (SWOT) analysis of the factors of critical importance for the evaluation of alternative strategies, and (b) the analytical hierarchy process (AHP) applied for the quantification and use of these factors for the selection of the most advantageous strategy. In this context, it is based on expert judgement. The results indicate that the proposed analysis can be used as a practical decision-making tool to resolve complex problems related to the mine closure and post-mining issues. [ABSTRACT FROM AUTHOR]

Post-mining soil and solid waste from the silica sand refining industry is widespread and the potential long-term impact of toxic metals and metalloids is a significant and under-appreciated issue. This study presents the characteristics of post-mining soil and solid waste resulting from silica sand purification to observe its physical, chemical, and biological composition. Analysis of the physical properties was carried out with reference to ASTM 112-10 and the results show that post-mining soil contains 36.95% sand, 18.80% clay, and 42.74% silt, with coefficients of permeability and porosity of 0.69 × 10-6 cm. s-1 and 35.84%, respectively. Meanwhile, the solid waste contains 43.35% sand, 35.96% clay, and 20.68% silt with coefficients of permeability and porosity of 1.49 × 10-6 cm.s-1 and 51.12%. The overall mineralogy and morphology of both samples showed that they have the same chemical composition as gehlenite (Ca2Al2SiO7), spinel (MgAl2O4), akermanite (Ca2MgSi2O7), monticellite (CaMgSiO4), aluminum oxide (Al2O3), magnetite (Fe3O4), and hematite (Fe2O3) supports this data. The chemical composition of both samples is SiO2, Al2O3, CaO, and MgO, but the post-mining soil has lower heavy metal and nutrient contents compared to solid waste. Meanwhile, solid waste has a high content of heavy metals and nutrients due to washing and bonding from the silica sand purification process. The abundance of bacteria (Colony Forming Unit) for the 10-4 and 10-5 dilutions in post-mining soil was 1.59 × 103 and not detected, while in the solid waste, 4.10 × 105 and 1.64 × 105 were found, respectively. This study can be used as base values for modifying the two samples, which can be applied in mining land reclamation.

In this study, leaves of the evergreen holm oak Quercus ilex were used to assess airborne contamination of potentially toxic elements (PTEs) at five towns located on the slopes of the Mt. Amiata (central Italy), an area with a long history of mining and, more recently, an important district for the industrial exploitation of geothermal energy. PTE composition and covariance of washed and unwashed Q. ilex leaves of three different ages (6, 12 and 24 month-old) were used to identify atmospheric inputs of PTEs at residential areas, evaluate long-term adsorption and retention of PTEs by the leaves, thus providing an indication of potential human exposure. Moreover, the determination of foliar concentrations of major elements (C, N, S and P) allowed an assessment of the nutritional status of the investigated urban tree stands which excluded the existence of stress condition caused by air pollution or other disturbances. Results indicated that overall Pb, Cu, and Cd concentration were low in the investigated urban sites, if compared with similar studies conducted in larger Italian cities, denoting a low contribution of vehicular traffic to the atmospheric pathway. The five urban settlements were characterized by a specific profile of elements (Al, Ba, Hg and Sb) enriched in unwashed leaves, resulting from the distinct geochemical characteristics of the area and from diffuse (i.e., urban activity) and point sources of PTEs emission (i.e., brownfields, geothermal power plants). The latter sources primarily govern the distribution of Hg, whose contamination was found to be very localized close to a major abandoned mining area. Our data provided quantitative evidence of the spectrum of PTEs potentially impacting resident population and may prove useful in support of follow-up instrumental monitoring campaigns of air quality, as well as for human health and ecological risk assessments. [ABSTRACT FROM AUTHOR]

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Spatio-temporal ground-movement measurements and mappings have been carried out in the Campine coalfield in Belgian Limburg since the closure of the mines to document post-mining effects. MT-InSAR measurements are compared to groundwater head changes in the overburden and to height data from the closest GNSS stations. Radar interferometry is used to estimate the extension and the velocity of ground movements. In particular, the MT-InSAR technique has been applied to SAR acquisitions of the satellites ERS-1/2 (1991–2005), ENVISAT (2003–2010), COSMO-SkyMed (2011–2014), and Sentinel-1A (2014–2022). The images were processed and used to highlight a switch from subsidence to uplift conditions in the western part of the coal basin, while the eastern part had already been affected by a rebound since the beginning of the ERS-1/2 acquisitions. Following the closure of the last active colliery of Zolder in 1992 and the subsequent cease of mine-water pumping, a recharge of mine-water aquifers occurred in the western part of the basin. This process provoked the change from subsidence to uplift conditions that was recorded during the ENVISAT period. In the center of the coal-mining area, measured uplift velocities reached a maximum of 18 mm/year during the ENVISAT period, while they subsided at −12 mm/year during the ERS-1/2 period. Mean velocities in the western and eastern parts of the coalfield area have decreased since the last MT-InSAR measurements were performed using Sentinel-1A, while the Zolder coal mine continues to rise at a faster-than-average rate of a maximum of 16 mm/year. The eastern part of the coalfield is still uplifting, while its rate has been reduced from 18 mm/year (ERS-1/2) to 9 mm/year (Sentinel-1A) since the beginning of the radar–satellite observations. Time-series data from the two GNSS stations present in the study area were used for a local comparison with the evolution of ground movements observed by MT-InSAR. Two leveling campaigns (2000, 2013) were also used to make comparisons with the MT-InSAR data. The station's measurements and the leveling data were in line with the MT-InSAR data. Overall, major ground movements are obviously limited to an extension of the actual underground-mining works and rapidly diminish outside of them. [ABSTRACT FROM AUTHOR]

The Donbass coal industry is currently undergoing critical changes due to post-mining of the coal industry in the context of the armed conflict in eastern Ukraine and the predominant use of autorehabilitation flooding of unprofitable mines (“wet conservation” scheme). The massive decommissioning of mines in developed (old) coal-mining areas disrupts the relatively balanced ecological state of the natural and man-made technogenic geosystem (TGS) “mining complex of the coal mine-environment”, primarily due to irreversible changes. According to our estimates, the following ecological and man-made changes in the underground and surface hydrosphere of Donbass, subject to further implementation of the modern post-mining scheme, include the following: 1) regional intensification of underground aquifers pollution in the zone of active water exchange (AWE – predominant formation of fresh water) and surface water bodies (rivers, lakes, reservoirs, domestic wells, springs) by heavy and toxic chemical elements; 2) deterioration of bioproductivity in large areas “mining complex – environment”; 3) development of areas of flooding and inundation of lands with acceleration of pollutants migration into the underground and surface hydrosphere; 4) additional subsidence of the earth's surface due to water saturation of previously drained rocks and reducing their compressive strength; 5) violation of the hydrological (balance, level, hydrochemical) regime of the river network in places of interception of surface runoff in areas of the earth’s surface additional subsidence and the destruction of regional watersheds; 6) formation of persistent pollution areas of bottom sediments of surface water bodies with toxic chemical elements and organic compounds that contribute to the long-term deterioration of water-ecological parameters of surface runoff and the first from the surface of the groundwater aquifer; 7) regional deterioration of ecological and hygienic safety of drinking water supply systems of cities and settlements within the Donbass coal zone.

The end of hard coal mining in Germany and other European countries has been leading to new challenges in post-mining and utilisation of abandoned mines while opening up new perspectives concerning the remains of former mining as well as new fields of work for specialised personnel at the same time. Coping with the resulting perpetual tasks places new demands on already trained experts and offers the opportunity to familiarise the next generation of students with post-mining issues and solution approaches from the beginning. This article presents two closely interrelated projects – the USAMIN Project and the PepperMINT Project – which aim to successfully recruit and train future professionals. For this purpose, the USAMIN (USe of Abandoned MINes) Project creates a new form of distance learning as multilateral cooperation, which strengthens the training of specialised experts and the scientific exchange across European borders. Furthermore, the main goal of this project is the establishment of networks between scientists and other experts, thus strengthening international cooperation. The PepperMINT Project’s STEM online courses aim to motivate high school students to pursue STEM studies by introducing them to the field of engineering, while simultaneously strengthening students, especially in their first semesters. By linking the two projects, various actors can be connected according to their education and a large part of the education chain can be viewed in a holistic approach. [ABSTRACT FROM AUTHOR]

Mining of minerals impacts all components of the ecosystem and the post-mining environment should be continuously monitored to control the quality and efficiency of reclamation procedures. In the past post-mining areas often did not undergo the full process of reclamation and were left unmonitored. This study was aimed at analysis of surface (gully) erosion in an abandoned lignite post-mining area located in the present cross border German-Polish Geopark Muskau Arch. For this purpose, low-cost unmanned aerial vehicle (UAV) photogrammetry to acquire data describing the surface condition of partly rehabilitated dump sites and subsequently a digital elevation model (DEM) of difference (DoD) approach to analyse quantitatively elevation change were applied. The results based on processing of data from four UAV missions carried out between Spring 2020 and Autumn 2021 (18 months) allowed to determine the elevation models with high accuracy (±0.02 – ±0.04 m) and develop differential elevation models for the estimation of material movement and surface change in three selected gullies. All of the study sites were subjected to surface erosion probably due to the effect of rainfall that caused natural landscaping of the area. The greatest observed elevation changes connected with loss of material in research crosssections reached 0.9 m. The UAV based data calculation of the DEM of difference has proved a time efficient and accurate method for analysis of elevation change in post-mining areas subjected to surface erosion. For the best results it is recommended to plan the UAV flight missions when the sun is at its highest or in cloudy weather to minimise the effect of sunshading on the quality of the generated DEMs. A further study to correlate material movement with precipitation records is planned. [ABSTRACT FROM AUTHOR]

The Ruhr Basin in Germany is one of the most extensively studied 3D rock volumes due to subsurface coal mining over the past centuries. With the final closure of the last coalfield in 2018, mine flooding was initiated and may result in induced ground movements. However, abandoned coal mines also provide the possibility for post-mining geothermal utilisation. To improve the understanding of rock properties with respect to flow properties and heat flux in the Ruhr Basin, three drill cores of clastic sedimentary rocks of the Westphalian A (Langsettian) and Westphalian B (Duckmantian) were characterised and the facies analysed. The studied 270 m core material show 4th order sequences of coarsening- and fining-upward cycles in an overall shallowing upward trend. Up to 17 m thick sandstone beds are associated with the delta front, mudstones and siltstones are related to the lower delta plain and up to 4 m thick coal seams linked to wetlands of the lower delta plain. Rock properties show low compressional velocities with a minimum of 2,886 m/s in sandstones of the delta front, which are negatively correlated with porosities of up to 15.6%. Likewise, porosity is a major control on thermal conductivity with a minimum of 2.3 W/(m×K) for high porosity sandstones. For less porous samples, thermal conductivity becomes less dependent on porosity but more strongly on mineralogy. Comparing our results with accessible thermal conductivity data from North Rhine-Westphalia (NRW), the high values of up to 5.3 W/(m×K) seem promising for potential geothermal applications. Furthermore, the results of this study imply that the classification based on facies associations is less suitable than the classification based on grain sizes in order to assess the geothermal potential. Overall, the Upper Carboniferous (Pennsylvanian) samples of this study show low porosity (mean 5.6%) and permeability (mean 0.1 mD). Thus fluid flow during mine flooding and potential future geothermal applications will primarily rely on permeable faults and fracture systems around the abandoned mine galleries as well as the galleries themselves. [ABSTRACT FROM AUTHOR]

As part of the FloodRisk project, the influence of rising mine water in abandoned coal mines on induced seismicity is investigated. The Seismological Observatory of the Ruhr University Bochum operates a monitoring network for the whole Ruhr area (North Rhine-Westphalia, Germany) since 1983. The local scale FloodRisk network was installed in the eastern part of the Ruhr area in 2020. The continuous monitoring opens up the opportunity for a long-term study of seismicity in combination with water levels related to mining in the region. The resulting database for the eastern Ruhr area includes over 13,000 induced earthquakes in a period of 26 years during active mining, very few events in the postmining phase before the onset of flooding and more than 1,700 events in the first two and a half years of flooding. The seismological database is supplemented by the mine water levels, which are regularly measured at various measuring points distributed over the study dewatering area “Haus Aden” and made available by Ruhrkohle Aktiengesellschaft (RAG). Seismic activity was highest in the phase of active mining and concentrated in the vicinity of the mining areas. After the end of mining, only very low seismicity was detected. With the start of flooding, significantly more events were registered again. The rise curve of the mine water level and the temporal and spatial distribution of the seismicity are observed and analysed. Five temporal flooding phases are identified in which the correlated seismicity shows different distribution patterns. Phases in which the levels of individual sections of the mine merge in flooding show particularly high seismicity. A strong spatial clustering of well-localised events occurs below the deepest flooded levels of the mine. Several mechanisms that alter the stress in active mining and flooded mines and induce seismic events are known from previous studies. To apply this to our study, particular attention is given to the spatial distribution of seismicity in relation to known geologic and mining structures. In the flooding phase, most of the seismicity is localised in the area below the flooded drifts. [ABSTRACT FROM AUTHOR]

For the Research Centre of Post-Mining (FZN) at the Technische Hochschule Georg Agricola University (THGA) in Bochum, geomonitoring is a multi-level approach to environmental monitoring with a focus on post-mining activities. In situ, a precise understanding of natural processes, e.g. the condition of groundwater, water bodies, soil or vegetation, is developed – usually through mapping, laboratory analyses and installed sensors. The goal is to later be able to derive an areawide statement on these processes through the analysis of satellite data. In order to be able to transfer the process understanding gained to the satellite data, an unmanned aerial vehicle is used. This article highlights an essential aspect of the in situ component. The denser the coverage with sensors, the more reliably an area-wide statement about drones and satellites can succeed. This is why low-cost temperature and soil moisture sensors and loggers are also used in the FZN research projects. In the “Climate Change – Management and Monitoring (C2M2)” project, funded by the Emschergenossenschaft-Lippeverband (EGLV), such sensors could be evaluated in several tests. The article presents initial results aimed at mapping an annual cycle of soil moisture with such inexpensive sensors. As a result, no physically correct measurements can be achieved with these sensors, but they are able to show patterns in processes and, for example, map such annual cycles. With the appropriate interpretation, they can thus deliver a contribution to understand processes. [ABSTRACT FROM AUTHOR]

Fractures in subsurface lithologies globally host economically significant energy resources and can be preferential fluid migration pathways. With the naturally fractured Upper Carboniferous sandstones of the Ruhr Basin located within Germany’s most densely populated area, the utilisation for powering one of Europe’s largest district heating infrastructure can be an option. Since the Upper Carboniferous sandstone matrix exhibits poor reservoir quality (average porosity: 8%, permeability: up to 3 mD), fractures are believed to primarily control fluid flow. By combining data from two outcrops (exposing the Namurian C and Westphalian A) with a wellbore data set (penetrating the Westphalian A), this study aims to develop a refined understanding of the fracture network. The present-day stress control on hydraulically conductive fracture orientations is studied by performing critically stressed fracture analysis for three different SHmax orientation scenarios. Kaisberg (Namurian C) and Finefrau (Westphalian A) Sandstone outcrops show three dominant fracture trends: NNW– SSE to N–S, NNE–SSW to NE–SW and WNW–ESE. The characterised fracture networks of both outcrops follow a top-bounded height distribution pattern, with fractures being mostly bed restricted. Therefore, bed thickness is identified as a controlling factor limiting fracture height. Based on 600 m of oriented core material from the Upper Carboniferous strata (Bork 10 wellbore), the analysis of the in-situ fracture network revealed two dominant fracture orientations: N–S and W–E. Fracture intensity indicates a varying degree of fracturing of the drilled sandstone layers for both trends (N–S: 0 to 9.1 m-1, W–E: 0 to 8.8 m-1). Comparison of dipmeter log fracture interpretations with reliable core description data shows a poor match (11%) for depth location (± 6 m) and dip azimuth (± 25°). Slip tendency analysis highlighted near-vertical N–S and NW–SE striking fractures to be generally favourably oriented for reactivation within the active stress field. In total, 10% of the detected fracture population (Bork 10 wellbore) are critically stressed under present-day stress conditions and may contribute to large scale fluid flow in the subsurface. [ABSTRACT FROM AUTHOR]

Mining of hard coal creates large underground cavities, which significantly affect the subsurface and land surface. Observations of land surface behaviour after the closure of mines demonstrate that these threats do not disappear. During mine water rebound in the post-mining phase of underground coalmines, the water flows into the open mine workings and other altered or fissured areas. This paper provides early observations from the PostMinQuake project, which is designed to identify mechanisms, relevant parameters and dependencies of mining and geological parameters causing post-mining seismicity in several European coal regions. It also presents the correlation between seismicity and water table level in the studied basins that has been observed during the post-mining phase and shows the necessity of implementing new procedures to monitor these seismic events. [ABSTRACT FROM AUTHOR]

The successive end of hard coal mining, which took place in the various coalfields in Germany by 2018, poses the risk of possible future mining damage related to mine water rise after mine closure. In this study, an interdisciplinary approach of structural geological and geochemical methods was applied to detect active fault zones, as a first step for long-term monitoring of mine flooding. The geomechanical analysis in the area of the soil gas campaign at the former coal mine “Haus Aden” shows high dilation and moderate slip tendencies as well as the potential for critical stress of the selected fault section of the Königsborn Fault. These features indicate the section under consideration as a preferred gas migration pathway. Soil gas measurements showed correspondingly clear anomalies of the components CO2, 222Rn and O2, which together with the results of the geomechanical analysis are a strong indicator for a structurally controlled migration of the gases and thus evidence of the modelled fault outcrop. A possible accompanying fault could not be identified properly, mainly because of the ambiguous CO2 concentrations. A positive correlation of CO2 and 222Rn can be a supplementary statistical tool to better assign unclear gas anomalies. However, this approach is limited by the radioactive decay of 222Rn and individual site parameters (groundwater, gas permeabilities). The primary mine gas CH4 could not be detected, which is probably related to its oxidative decomposition with formation of CO2. In the next step, it is planned to validate the current results with area-wide measurements if possible and then to expand selected boreholes to gas gauges. Newly developed, permanent gas sensors will be installed into these gas gauges for long-term monitoring of mine flooding. The aim is to provide new low-cost options for flooding monitoring in order to be able to estimate induced seismicity and mine damage. [ABSTRACT FROM AUTHOR]

In the coal phase-out era, achieving sustainable mine closure is significant and prioritizes targets for the mining industry. In this study, the already closed lignite mine of Kardia, North Greece, is investigated, where the mine void left is naturally filled with water. The viability of different repurposing land uses is evaluated, and the natural water level development inside the mine pit is investigated concerning its future uses. The potential for solar photovoltaic (PV) panels developed on mining land and its surrounding area is evaluated in combination with the application of pumped hydro storage (PHS) technology, utilizing pit lake water. Except for electricity system planning, other end-uses that offer multiple, mutually reinforcing and lasting benefits are investigated, such as recreation parks, terrestrial wildlife, aquaculture and agriculture. All repurposing scenarios are evaluated with regard to the spatiotemporal evolution of the lake, by generating forecasts of the dependent variables (rainfall and temperature) via linear (autoregressive integrated moving average) and non-linear (artificial neural network) models. The prediction of pit lake natural development redefines the new land use layout and the land repurposing decisions. This is essential for strategic planning, considering the Greek lignite mining industry's priority regarding transitioning from the current coal-based electricity to renewable energy sources (RES) technology. [ABSTRACT FROM AUTHOR]

Recent changes in the fossil-fuel energy sector require coal mining industries to plan for the future, including developing procedures for decommissioning and closure associated with mines. In surface coal mining, the geotechnical issues of decommissioning include the long-term stability of the pit slopes, particularly as the pit is gradually filled with water. This paper investigates such slope stability issues, with emphasis on the conditions prevailing in the Amyntaion surface lignite mine, in Western Macedonia, Greece. Analytical and numerical methods have been developed and used to estimate the temporal evolution of the overall safety factor, as the water level in the pit rises, creating a lake. It is shown that until the water level in the lake reaches a critical depth of approximately 15–35% of the final equilibrium condition, the safety factor against the overall slope instability decreases slightly (by about 3% in the case study, and up to 5–10% in other conditions) compared to its value at the end of exploitation. At higher lake levels, the safety factor increases significantly, as the beneficial effect of the lake water pressure acting on the slope overcomes the adverse effect of pore water pressure rise inside the slope. In typical mines, the critical water depth is achieved within a few years, since the surface area of the pit is smaller at deeper levels; thus, more favorable slope stability conditions are usually reinstated a few years after mine closure, while the small reduction in safety during the initial stages after closure is inconsequential. The paper investigates the parameters influencing the magnitude of the small reduction in the short-term safety factor and produces normalized graphs of the evolution of the safety factor as the lake water level rises. The results of the analyses can be used in preliminary closure studies of surface coal mines.

Heavy metal elements concentration study has been determined from soils and tailing sediments in laterite nickel post-mining area in Motui District Southeast Sulawesi. This study aimed to determine the concentration of some heavy metal elements, especially Fe, Co, Mn and Cr, from surface soils sediments in waste dump sites and tailing sediments in settling ponds from lateritic nickel post-mining areas. A total of 20 samples consisting of 18 soil samples and 2 tailing sediments samples were systematically collected for the study. The soil samples from the waste dump site profile were collected from 3 layers which were divided based on the colour of the soils from top to bottom, namely Layer C, Layer D and Layer E. Six soil samples were taken from each layer with space between each sample in one layer was about 50 – 60 cm. The samples were sent to the laboratory and analysed using Atomic Absorption Spectrometer (AAS) method to determine the concentration of heavy elements. Metal-bearing minerals detected from the bedrock consists of chromite, manganese, magnetite and limonite which are responsible for the Cr, Mn and Co, and Fe content, respectively. The result showed that Fe content is significantly higher in soil samples from Layer C and tailing sediments with dark red to brown in colour, suggesting the strong relation between Fe content and colour index. The general element mobility trend showed that Mn and Co are positively correlated in soil sampling from all layers and tailing samples, whereas Fe and Cr show a negative correlation trend in Layer C, D and tailing sediments but positively correlated in Layer E.

With the adjustment of China's energy structure, decentralized coal mining has been transformed into refined, centralized and precise mining, which greatly reduces the number of coal mines in China.And a large number of coal mines with exhausted resources and backward production capacity are facing closure or abandonment.This transformation will confront China, at present and for a long time in the future, with a "post-mining" era similar to that in Germany.From the development trend of the transformation of China's energy structure and the macro strategy of coal resource development, there is no possibility to re-develop those coal mines that have been closed or will be closed.The closed mines not only cause environmental problems such as water and air pollution, but also social and economic problems such as difficulty in relocating employees and disposing fixed assets.Therefore, in view of the problems after the mining area is closed or abandoned, the treatment plans for post mining and the sustainable development strategy of resources in post mining industrial zone in Germany are referenced in this paper.Compared with the treatment schemes of closed mining areas in China, the concept that the utilization of resources after the closure of mining areas should be included in the top-level design of the whole mine development, and the idea of comprehensive utilization of coal underground space, mine water and other resources are proposed.Although various forms of abandoned mine utilization schemes have been put forward at home and abroad, the overall utilization rate is not high.It is still necessary to further explore the basic theories and methods of resource utilization in closed mining areas, as well as the corresponding education and technical personnel training measures to meet the development of these areas.

The objectives of this study were to determine the effects of biochar and manure additions to growth performance, nutrient value, in vitro digestibility, and rumen fermentation characteristics of Pennisetum purpureum cv. Mott grown in soil remaining after nickel-mining activities. The goat manure and iron wood biochar were used in this study. Treatments were arranged 4 x 2 factorially in a completely randomized block design. The factors were four levels of biochar (0, 5, 10, and 15 metric ton/ha) and two levels of manure (0 and 10 metric ton/ha). The plants were harvested at 70 days after sowing (first harvest), 128 days (first ratoon) and 193 days (second ratoon). Results showed that at first and second ratoon, plant height and tillering number were increased after 5 metric ton/ha biochar and 10 metric ton/ha manure additions (p < 0.05). Manure treatment resulted in higher crude protein content (p < 0.05) than controls at first and second ratoon stages. Combinations of biochar (p < 0.01) and manure (p = 0.09) improved in vitro gas production from the insoluble fraction (b). The study concludes that treatment with 5 metric ton/ha biochar and 10 metric ton/ha manure fertilizers on post-nickel-mining soil increases tillering number, height, CP content and in vitro digestibility of P. purpureum cv. Mott at ratoon stages. [ABSTRACT FROM AUTHOR]

Post-mining soil and solid waste from the silica sand refining industry is widespread and the potential long-term impact of toxic metals and metalloids is a significant and under-appreciated issue. This study presents the characteristics of post-mining soil and solid waste resulting from silica sand purification to observe its physical, chemical, and biological composition. Analysis of the physical properties was carried out with reference to ASTM 112-10 and the results show that post-mining soil contains 36.95% sand, 18.80% clay, and 42.74% silt, with coefficients of permeability and porosity of 0.69×10-6 cm·s-1 and 35.84%, respectively. Meanwhile, the solid waste contains 43.35% sand, 35.96% clay, and 20.68% silt with coefficients of permeability and porosity of 1.49×10-6 cm·s-1 and 51.12%. The overall mineralogy and morphology of both samples showed that they have the same chemical composition as gehlenite (Ca2Al2SiO7), spinel (MgAl2O4), akermanite (Ca2MgSi2O7), monticellite (CaMgSiO4), aluminum oxide (Al2O3), magnetite (Fe3O4), and hematite (Fe2O3) supports this data. The chemical composition of both samples is SiO2, Al2O3, CaO, and MgO, but the post-mining soil has lower heavy metal and nutrient contents compared to solid waste. Meanwhile, solid waste has a high content of heavy metals and nutrients due to washing and bonding from the silica sand purification process. The abundance of bacteria (Colony Forming Unit) for the 10-4 and 10-5 dilutions in post-mining soil was 1.59×10³ and not detected, while in the solid waste, 4.10×105 and 1.64×105 were found, respectively. This study can be used as base values for modifying the two samples, which can be applied in mining land reclamation. [ABSTRACT FROM AUTHOR]

After 1990, when the economic system changed in Romania, the mining industry was the most controversial field from a productive-economic point of view and subject to reforms and transformations for efficiency. Currently (2022), there are nine main mining perimeters in which the production of useful, energetic, and nonenergetic mineral substances is operational, and in others it has decreased or stopped. Still active mining areas need economic and ecological assessments to identify similarities and proximity symmetries for informed exploitation decisions and feasible complex resource utilization. The main objective of our study is to define a framework for the theoretical and practical contribution to the substantiation of decisions and expressions of interest regarding future investments in mining projects for useful and energetic and non-energetic mineral substances in Romania. Investments in the mining industry are expensive, with major risks and subunit success rates for specific geotechnological conditions. The purpose of the research is to provide the methodology for using some variables of similarities from proximity mining deposits in the stage of exploitation or post-exploitation affected by anthropogenic activity in the national geological territory through a case study of Romania. With the help of statistical scales, the research results highlight that in the exploitation and post-mining perimeters in Romania, the states of "affect" and "post-affect" anthropic, respectively, of eco-economic damage are in a maximum proportion of approximately 36% in relation to the ideal situations of no affect. For a mining investment project, knowing similar or symmetrical exploitation and post-exploitation properties and situations, and from the geological deposits in the vicinity, premises are created for optimized strategic and tactical decisions, based on reality and, above all, for the provision of expressions of interest for new investments that have a programmed, expected success rate. [ABSTRACT FROM AUTHOR]

Sustainable mine closure is one of the main priorities of the mining industry. This aim of this research was to predict the spatiotemporal development of water levels in a mined-out pit by generating forecasts of the dependent variables (rainfall and temperature) via linear (autoregressive integrated moving average) and non-linear (artificial neural network) models. We investigated natural water level development in one mined-out pit of the closed lignite mines in Amynteon, north Greece, with no artificial recharge. The forecasted rate of water level increase was estimated to be ≈ 10 m per year in the 'early' stage of pit lake spatiotemporal evolution (first 10 years), and 0.1 m per year in the 'last' stage of potential lake development (after year 2060). Also, the optimum lake surface (i.e. the level where no significant increase in water level rate appears) was estimated at + 520 m, which was predicted to occur in ≈ 40 years. The proposed methodology was validated via water level measurements performed during the first year of lake development, where field measurements of water elevations closely followed predictions. Forecasting pit lake water levels is essential for strategic planning, examining pit lake repurposing options, and informing decisions about post-mining futures and economic transitions. [ABSTRACT FROM AUTHOR]

Recent changes in the fossil-fuel energy sector require coal mining industries to plan for the future, including developing procedures for decommissioning and closure associated with mines. In surface coal mining, the geotechnical issues of decommissioning include the long-term stability of the pit slopes, particularly as the pit is gradually filled with water. This paper investigates such slope stability issues, with emphasis on the conditions prevailing in the Amyntaion surface lignite mine, in Western Macedonia, Greece. Analytical and numerical methods have been developed and used to estimate the temporal evolution of the overall safety factor, as the water level in the pit rises, creating a lake. It is shown that until the water level in the lake reaches a critical depth of approximately 15–35% of the final equilibrium condition, the safety factor against the overall slope instability decreases slightly (by about 3% in the case study, and up to 5–10% in other conditions) compared to its value at the end of exploitation. At higher lake levels, the safety factor increases significantly, as the beneficial effect of the lake water pressure acting on the slope overcomes the adverse effect of pore water pressure rise inside the slope. In typical mines, the critical water depth is achieved within a few years, since the surface area of the pit is smaller at deeper levels; thus, more favorable slope stability conditions are usually reinstated a few years after mine closure, while the small reduction in safety during the initial stages after closure is inconsequential. The paper investigates the parameters influencing the magnitude of the small reduction in the short-term safety factor and produces normalized graphs of the evolution of the safety factor as the lake water level rises. The results of the analyses can be used in preliminary closure studies of surface coal mines. [ABSTRACT FROM AUTHOR]

This paper presents the results of numerical simulations carried out to confirm the influence of former mining activities on deformation of the mining terrain. The assessment of deformation changes was carried out with the use of FLAC3D program based on the finite difference method. Numerical calculations were carried out for the example of actual mining operations in seams 703/1-2 and 707/2 of “Marcel” Coal Mine. Taking into account the influence of the model’s plastic features and the so-called activation of a higher occurring seam in conducted simulations enabled obtaining a very good description of the measured subsidence. Based on the results one may state that numerical model can be used to assess the influence of former mining activities and the direction of conducted exploitation on deformations of the mining terrain. These factors are not recognized by geometric-integral theories commonly used for predicting the influence of mining operations on the surface. The results presented in this paper confirm that the applied method of simulating the phenomenon of reactivation of post-mining goafs is correct.

Ecological restoration with a multispecies and multifunctional approach can accelerate the re-establishment of numerous ecosystem services. The challenges with land that is degraded, damaged, or destroyed post-mining are the low productivity of soil and the high potential for contaminants. Herein, we evaluated the multispecies and multifunctional approach to restoration strategy through a mixture of woody and herbaceous species, microsymbiont and biochar amendments, and plant spacing. The experiments were conducted using greenhouse and field trials located in Quebec, Canada. We used a mixture of tree species (Alnus viridis (Chaix) DC. ssp. crispa (Aiton) Turrill, Picea glauca (Moench) Voss, Populus tremuloides Michx. and Salix arbusculoides Andersson) and herbaceous species (Avena sativa L., Festuca rubra L. and Trifolium repens L.) on two types of gold-mine waste materials (fine tailing and waste rock). The biochar amendment and microbial inoculation were applied on both greenhouse and field trials. We found both positive and negative effects of plant spacing, biochar amendment and inoculation depending on their interactions. The net positive effect was shown by combining high plantation density, biochar, and inoculation factors on Alnus viridis ssp. crispa. Overall, plantation density was shown to be the most important factor in generating the net positive effect. We suggest that the mechanism was correlated with the improvement in microclimate through soil plant water conservation and microbial activity enhancement over soil temperature modification. Hence, we propose to put emphasis on microclimate improvement for accelerating the restoration processes, along with other combined factors, including microbial inoculation and biochar amendment.

In the context of a groundswell of interest in developing innovative post-mining landscapes, this paper explores post-mining imaginaries through the example of a recently closed coal mine, Leigh Creek in South Australia. We explore how these imaginaries are put forward by the mine's local communities, multiple levels of government and the mining company itself. In this case, as occurs more broadly in coal mining, these imaginaries are co-constructed by the ever-present risk of underground spontaneous combustion—spon-com—as a result of mining practices. This article addresses the role of spon-com as not only a physical phenomenon of the underground, but as a socio-environmental mechanism wielding considerable political power in relation to post-mining possibilities. We contribute to the geopolitical discourse on the 'subterranean turn' by drawing on concepts of haunting-as-circumstance to explore the political agency of the underground to reach above and manipulate surface politics. We thereby complicate Maria de Lourdes Melo Zurita's identification of a pre-existing sub terra nullius that positions the subsurface as political nothingness awaiting human intervention. This is a crucial step forward in thinking through concepts informing understandings of surface–subsurface relations, including the introduction of spectral thinking within subterranean geopolitics. We thus advance scholarship on subterranean geographies by progressing concepts of inhuman agency grounded in a situated example of this agency in practice. [ABSTRACT FROM AUTHOR]

Succession is a basic natural process of ecosystem recovery, it may start completely de novo (primary succession) or after serious disturbance of the previous ecosystem (secondary succession). Despite most reclamation and restoration approaches depending on it and despite extensive previous research, we found no worldwide review that would describe the pattern of vegetation cover and woody vegetation recovery in individual types of succession and explore major factors that affect the speed of vegetation recovery. To fill this gap we have searched world literature and extracted data about 244 succession series about total vegetation cover and 113 about woody vegetation cover. The rate of vegetation cover recovery is significantly slower during primary succession than during secondary succession, this however not apply to woody vegetation. The type of disturbance affects the speed of recovery, post‐mining sites recover fastest among primary succession and older fields were the fastest among secondary succession, the slowest one being succession in glacier retreats. Latitude, soil pH, the size of the disturbed area, temperature, and actual evapotranspiration affect the rate of vegetation recovery in primary succession, while only latitude affects secondary succession. Some other factors affect succession after a specific disturbance. The study shows that succession can be an effective tool to restore vegetation cover and woody vegetation on many occasions. We expect that differences in the nutrient availability determine differences in the rate of total vegetation cover recovery, while soil porosity (compaction) may be an important factor affecting woody vegetation recovery. [ABSTRACT FROM AUTHOR]

Underground and opencast mining adversely affects the surrounding environment. This process may continue even decades after the end of actual mineral extraction. One of the most significant effects of ceased mining are secondary deformations. Safe, new development of post-mining areas requires reliable information on potential deformation risk zones, which may be difficult to obtain due to a lack of necessary data. This study aimed to investigate and understand the secondary deformation processes in the underground mining area of the former "Babina" lignite mine, located in the unique glaciotectonic environment of the Muskau Arch, in western Poland. A combination of GIS-based historical mapping, geophysical 2D/3D microgravimetry, and Electrical Resistivity Tomography (ERT) measurements allowed the identification of subsidence-prone areas and the determination of potential factors of sinkhole development. The latter are associated with anthropogenic transformation of rock mass and hydrogeological conditions, by shallow underground mining. The results confirmed that multi-level mining of coal deposits in complex and complicated glaciotectonic conditions cause discontinuous deformations, and may be hazardous as long as 50 years after the end of mining operations. [ABSTRACT FROM AUTHOR]