Post-mining Areas Research Articles

Energy crop as an environmentally sustainable reclamation option for post-mining sites: a life cycle assessment of cassava planting in Vietnam.

Using post-mining areas for planting energy crops has emerged as a promising and sustainable reclamation solution due to its potential contributions to environmental protection, land restoration, and especially energy security. However, to ensure the sustainability of this reclamation solution, its environmental performance needs to be thoroughly assessed case by case. Located in Ha Thuong Commune, Dai Tu District, Thai Nguyen Province in northern Vietnam, Nui Phao is the world's largest tungsten mine. To restore post-mining sites at Nui Phao, cassava planting for ethanol production was one of the proposed measures. To support the decision-making, this study employs life cycle assessment to thoroughly evaluate the environmental performance and potential environmental benefits/costs of cassava-based reclamation system in terms of resource consumption and green house gas (GHG) emission. The results show that cassava-based reclamation might bring significant environmental benefits in terms of fossil fuel saving and GHGs reduction (i.e., reduce 50% fossil fuel consumption and 36% GHGs emission); however, it does not bring any benefit in terms of water and land resource consumption. Moreover, the results define cassava cultivation as the "hot spot" of the system, where innovations to enhance the yield and reduce water and fertilizer consumption are required to improve the environmental performance of the cassava-based reclamation system.

How Do Observable Characteristics of Post-Mining Forests Affect Their Attractiveness for Recreation?

Afforestation is a popular practice of the recovery of landscape affected by open-cast coal mining. We investigated what impact the observable characteristics of restored forests have on their attractiveness for recreation framed as a one hour walk in a respective type of forest. In this study, we elaborate on some of the observable characteristics which have been previously found in the literature to affect the perceived attractiveness of outdoor environments. Environmental preference data were collected online using a quasi-representative sample of affected and control populations of the Czech Republic (N = 869). The questionnaire employed visual representations of typical reclaimed forest sites on spoil heaps in the Sokolov mining district. A mediation analysis revealed that forests growing in post-mining areas are perceived more negatively than the typical commercial spruce forest due to their lower permeability, lower level of stewardship, and perceived low safety. However, there are differences in observed characteristics also between different types of restored forests, even when controlling the effect of forest age. The results show for forestry practice that while some of the observed characteristics change by themselves with the increasing age of the forest (permeability, perceived safety, and naturalness of successional forests), improvement in others requires targeted after-care (perceived stewardship). In any case, our results are promising in that they imply that the recreational value of restored forests in post-mining areas may further increase in the future.

Carbon-stock estimation in three types of coal post-mining reclamation at East Kutai Regency, East Kalimantan

The success of a reclamation process could be evaluated by calculating the carbon stocks in the area. Carbon stock is an ecosystem service that can be assessed quantitatively. The reclamation process in the coal post-mining area in East Kalimantan needs to be assessed by comparing it to the reference area. The aim of this study was to determine the value of carbon stock in the three types of coal post-mining reclamation areas (Type A: without shade trees, Type B: with one species shade trees, Type C: with more than one species of shade trees), then compared to the natural forest area used as the reference site. The research was carried out by making plots inside the reference site and in the reclamation areas, at the tree, poles, and sapling stages. The results were analyzed descriptively and statistically for each reclamation type refer to the conservation area. The results showed that reclamation type C, with older year plant, had higher carbon stock compared to Type B, or Type A, ie. 51.9 t C/ha, 37.8 t C/ha, and 2.9 t C/ha respectively. However, the carbon stock in the three types of reclamation area is still much lower, than the conservation area which reaches 296.8 t C/ha. Thus, the older and more diverse species planted in a reclamation area plant, the higher carbon stock saved. Moreover, planting shade trees can also help increase the value of carbon stocks in a reclamation area.

Restoration of minesoil organic matter by cultivation of fiber hemp (Cannabis sativa L.) on lignite post-mining areas

We propose here the use of fiber hemp (Cannabis sativa) introduced into post-mining area to be a pioneering plant that can be used for reclamation of the soil degraded by opencast lignite mining. Five years experiment carried out on the total surface of 7.5 ha showed usefulness of hemp as a species used for rebuilding the soil organic matter. By plowing in the whole biomass of cultivated plants it was delivered to the topsoil, accelerating the restoration of the humus layer. Organic matter content of the soil increased from 0.87 % to 2.4 %. In the same time the content of important macroelements like phosphorus, potassium, magnesium and manganese reached the levels above minimum for agricultural soil, while heavy metals (Cu, Zn, Fe) did not exceed an acceptable level.

Predatory mite instars (Acari, Mesostigmata) and decomposing tree leaves in mixed and monoculture stands growing on a spoil heap and surrounding forests

In the past, ecological research mainly omitted the sexual and developmental variability of mite communities, and therefore could not fully reflect the actual state and function of mite communities in the ecosystems studied. The aim here was to analyze how habitat conditions (mixed vs. monoculture stands) and single-species litter of 14 tree species (in mixed stands) affect the sex and developmental stages of Mesostigmata mites living on the decomposing litter. The research was conducted in 2011–2016, at the Bełchatów Lignite Mine external spoil heap (Central Poland) in mixed stands growing on the spoil heap, as well as in pine and birch monoculture stands growing on the spoil heap and an adjacent forest area. We found significant influences of habitat on females, males and juveniles. Additionally, we found that soil mean temperature had a significant effect on males and juveniles, but not on females. Moreover, despite the insignificant influence of litter species on mite communities, we found that percentage litter mass loss significantly affected female and juvenile mites. Taking into account habitat type, the percentage litter mass loss significantly affected female and male mites, but not juveniles. The mite abundance calculated per dry litter mass usually gradually increased during decomposition. Interestingly, the highest mean female, male and juvenile abundances were recorded in birch stands growing on the adjacent forest area; however, juvenile mites were also very numerous in mixed stands on spoil heap. Therefore, our results confirm that mixed stands on post-mining areas are a potentially better habitat for development of mesostigmatid communities compared to monocultures, among others by relatively higher humidity and lower temperatures.

Gas Migration in the Aspect of Safety in the Areas of Mines Selected for Closure

One of the main hazards occurring in post-mining areas is the uncontrolled migration of gases to the surface, which may pose a serious threat to life and health. These gases are mainly methane and carbon dioxide, in smaller amounts ethane and higher hydrocarbons, carbon oxide, hydrogen sulfide, and radon. Methane migrating into the lower levels of buildings, garages, cable ducts, and sewage systems reaching the concentrations of above 5% may cause an explosion hazard. The concentration of carbon dioxide over 4% also represents a serious threat to life. Moreover, carbon dioxide and methane, emitted into the atmosphere, constitute a considerable source of greenhouse gases. The methane could be utilized, yet it is necessary to develop effective capture and purification methods with the first step of determination being its migration routes. The paper presents the application of numerical modelling with the use of TOUGHv2.0 software, which enabled effective simulation of the multiphase flow, applying adsorption and diffusion phenomena. The results of gas migration modelling were compared to the outcomes of geological tests, and the obtained results were satisfying. It was observed that both geological investigation and computer simulations are proper tools for investigation of the phenomenon of gas migration and identification of gas hazard areas on the surface, constituting the basis for development of effective methane capture methods for further application.

Semi-Natural Areas on Post-Mining Brownfields as an Opportunity to Strengthen the Attractiveness of a Small Town. An Example of Radzionków in Southern Poland

The socio-economic and political changes of the end of the 20th century in Central and Eastern Europe had significant impacts on the transformation of urban spaces, especially in industrial and mining towns. The article attempts to explain the essence of these changes concerning the spatial development of—a small post-mining town in southern Poland. This article evaluates urban development policy in response to the significant land-use changes in the small post-mining city of Radzionków, with particular attention to the transformation of brownfield sites to semi-natural areas of regional importance. This issue is interesting for two reasons. First, this small city, located in a large European agglomeration, has to face competition focused on interesting regional projects. Second, there is a desire for reindustrialization as a remedy for job losses in mining and heavy industry. The successful establishment of a large botanical garden in this city provides a case study for discussing the future of small post-industrial cities and the development of land use policy regarding valuable natural areas located in post-industrial and post-mining areas. This study also indicates the vital role of the creative management factor.

Environmental impact control of coal mining activities in Kandangan Lama, South Kalimantan through calculating post-mining costs

Land clearing during mining activities can harm the environment, one of which is a change in the landscape that results in erosion, flooding, and climate change. This study aimed to determine the total cost of the post-coal mining plan and identify its components to control environmental impacts and climate change in Kandangan Lama, South Kalimantan. The method used to calculate the total cost of the post-mining plan is based on the Decree of the Ministry of Energy and Mineral Resources Republic of Indonesia with the number 1827 K/30/MEM/2018. The data sampling technique used purposive sampling through observation, interviews, and document study. The results showed that the post-mining area in this study was 3.46 ha. Direct cost, namely IDR 1,064,459,474.00, consists of land use, revegetation, demolition, restoration, social, cultural, economic development, maintenance, and monitoring. Also, the indirect cost is IDR 310,822,166.00, which consists of mobilization and demobilization costs, post-mining plan, contract administration and profits, and supervision costs. Thus, the total cost of the post-mining plan for the 3.46 ha was IDR 1,444,045,722.00. These costs are commensurate with the restoration of environmental conditions to control climate change to maintain environmental stability.

Isolation and identification of fungi associated with natural forest land and post-mining areas of PT. Vale Indonesia: Preliminary study

This study aimed to determine the types of fungi that can provide information on microbes associated with the post-mining forest land area of PT. Vale Indonesia. This study used a descriptive method by recording and describing the phenomena obtained. Sampling in the field was done by taking 500 g of soil/point (with three replications). Soil samples were taken around the roots or rhizosphere areas with 10 - 30 cm depth in natural and reclamation forest areas. Isolation of microbial growth was conducted by using the dilution technique. The purification of the obtained isolates was carried out by inoculation in PDA media with the point method, then incubated for ± 5 days at 27°C, and their growth was observed. Characterization of microscopic fungi isolates was identified based on the characteristics of the morphological structures. Based on preliminary research results of fungi soil samples originating from reclamation and natural forest areas, 11 rhizosphere fungi isolates were obtained. The fungi colonies’ color at the top and bottom had various colors and different textures. Greenish and whitish colors dominated the colony color, but some isolates had white, brown, cream, gray, yellowish, whitish, greenish colors, and some had spots. Colony texture was dominated by velvet, but some isolates had the texture of fine cotton and coarse cotton, presumably Aspergillus niger, Aspergillus sp, Fusarium oxysporum, Pénicillium sp., Trichoderma harzianum, and Trichoderma viride. This research will be continued to ascertain the type and function of each isolate.

Comprehensive method of assessing the flood threat of artificially drained mine subsidence areas for identification and sustainable repair of mining damage to the aquatic environment

The effects of mining, apart from surface subsidences and deformations, are forced flows of surface and underground waters, lasting many decades in the mining areas. Natural water flows should be restored by mining entities and/or their legal successors in the process of the mine closures. Such action is tantamount to a restoration of the previous state in the sense of repair of damage to the environment and surface infrastructure. Then, under natural water flows conditions, such mining areas may become flooded, often quite extensively. This paper describes a comprehensive method for flood threat assessment of artificially drained mining and post-mining areas after the restoration of natural water flows. The subject of this research is the surface of a single mine subsidence area. The term mine subsidence area (MSA) is defined as that part of the rock mass containing solid mineral deposits and the above surface affected by continuous and discountinuous deformation (as currently legally defined in terms of range and intensity). This method, together with simultaneous measurements of water levels at outflow places at the MSA boundary allows for an useful way of mapping the MSA surface. This has been developed to fully identify the true extent of mining-induced damage to the MSA aquatic environment. It introduces innovative hydromorphological elements of the MSA. These allow zoning of the MSA surface while taking into consideration future drainage works and/or projected mining subsidences inside the MSA. These spatial hydromorphological maps of the MSA identify the framework of permanent and occasional flooding and constitute the final result of this method. It is an universal tool for sustainable water management and quantitative evaluation for extraction of minerals.

Microgravity Survey to Detect Voids and Loosening Zones in the Vicinity of the Mine Shaft

In mining and post-mining areas, the assessment of the risks to the surface and its infrastructure from the opening or closed mine is of the utmost importance; particular attention should be paid to mine shafts. The risks include the occurrence of undetected voids or loosening zones in the rock mass. Their detection makes it possible to prevent their impact on a mine shaft and surface infrastructure. Geophysical methods, and in particular, a microgravity method lend themselves for the detection of changes in the distribution of masses (i.e., the density) due to voids and loosening zones. The paper presents the results of surface microgravity surveys in the vicinity of three mine shafts: under construction, working, and a liquidated one. Based on the gravity anomalies, the density distribution of the rock mass for all three cases was recognized. The properties of the anomalies allowed to determine which of the identified decreased density zones may pose a threat to the surface infrastructure or a mine shaft. The microgravity survey made inside the working mining shaft provided information on the density of rocks outside the shaft lining, regardless of the type of lining. No significant decrease of density was found, which means that there are no larger voids outside the shaft lining. Nevertheless, at a depth of 42 m in running sands layer, the decreasing density zone was located, which should be controlled. Additionally, measurements in two vertical profiles gave the possibility of directional tracking of density changes outside shaft lining. Such changes were observed on three boundaries of geological layers, with two of them being on the boundary of gypsum and other rocks.

Transforming post-mining area into expressway site by stability evaluation with clustering method: A case study

ABSTRACT Mining subsidence, as one of the most common geological hazards, bringing a massive threat to the new infrastructure in such a post-mining area. To evaluate the stability of a post-mining area transforming into an expressway site, a hybrid model based on the kernel principal components analysis (KPCA) and the fuzzy C-means clustering algorithm (FCM) was proposed by multi-attribute geo-mining variables. This study attempt to cover the inaccuracy clustering gap of conventional approaches with geo-mining stability influencing factors (SIFs), the model was established to cluster the status of a post-mining area with 9 geo-mining SIFs through 134 mined-out working panels of 6 collieries underneath the proposed Jining expressway site in Shandong province, eastern China. Taking the results of ground residual deformation calculated by the probability integration method (PIM) as a validation set, the prediction accuracy of the proposed KPCA-FCM model and conventional clustering approaches was compared. The major experimental results indicate that the maximum residual subsidence in the study area is 96 mm, after KPCA dimensionality reduction, the first four principal components of cumulative contribution rate were 83.83%, the external performance indicator Rand Index (RI) of the KPCA-FCM algorithm is 0.86, consistent with the actual status of the stability in the post-mining area. Overall, the performance of the proposed approach demonstrates the effectiveness of the stability evaluation in the post-mining area with multi-geo-mining SIFs and it is feasible to transform the post-mining area into the proposed expressway site.

Utilization of Compost as ameliorant in a Nickel post mining soil

Southeast Sulawesi is one of the nickel producing regions. Nickel mining activities in addition to positive impacts can also have negative impacts such as decrease of soil and increased of accumulation of heavy metals in the soil. Therefore, couple solutions are needed to improve the quality of nickel mining soil, one of those is by providing soil amendments. The material that used in this research is compost. Compost fertilizer contains humic acid which has cation exchange ability so that it can be useful for remediating the nickel post-mining area. The research used a complete randomized design method by variating the ratio of compost to nickel post-mining soil. The method steps consisting of (1) Analysis of post-mining soil sample (2) Analysis of compost-mixed mining soil sample. The results showed that the best treatment was the 17% addition of compost to nickel post-mining sample which characterized by changes in soil characteristics, such as pH value 6.68 to 7.17 (neutral) ; C-organic content 2.01% to 3.69% (high); N-total 0.19% to 0.21% (moderate); P2O5 21.77 mg /100g to 25.03 mg/100g (moderate); K2O 15.13 to 17.77 (low); and nickel content of 1194.66 ppm to 988.86 ppm. Despite a decrease of nickel content in the soil, its level is still hazardous in term of human health.

Does Experimental Non-Reclaimed Sites Differ from Technically Reclaimed Areas in the Risk of Artificial Bird Nest Predation?

Abstract Areas left to natural development have been found to be sites with higher diversity and conservation value of local communities, including bird communities, compared to artificial reclamation of post-industrial areas. Most of the studies conducted so far have focused primarily on bird communities of post-mining areas, in terms of the diversity and richness of species. Our study dealt with bird nest predation on specific case of two experimental sites (20 and 32 ha) with more than a 20-year history of primary spontaneous succession established within the technical reclamation of the Radovesická spoil heap (approx. 1,200 ha, North Bohemia, Czech Republic). In the spring of 2018, we conducted a predation experiment using artificial nests (ground and elevated), installed within both succession areas and beyond, in the adjacent artificially reclaimed areas. We monitored the way of restoration and the distance of the nest placement from the succession-reclamation sites edge. The rate of predation was very high: 92.5 % in reclaimed area and 89.4 % in spontaneous successions. None of the observed factors analysed in the generalised linear model (GLM) have conclusively explained the risk of predation. The two experimental succession sites did not differ from the surrounding reclaimed sites in terms of the risk of predation, nor did they significantly influence predation risk on reclaimed sites. We believe that both relatively small and mutually isolated areas do not provide enough of an inner environment without or with at least a limited effect of predation pressure coming from adjacent reclaimed areas.

Surface Deformations Resulting from Abandoned Mining Excavations

The occurrence of surface discontinuous deformations in post-mining areas is currently a significant and important problem, due to both the frequency of their occurrence and the threat they pose to public safety. This paper presents the results of research concerning the possibility of sinkhole formation in the areas of abandoned mining excavations. For the purpose of assessing the condition of the rock mass disturbed by the existence of numerous mining excavations, electrical resistivity tomography investigations were carried out for the selected area where mining was undertaken in the past at shallow depths and many underground workings accessing the deposit exist. The sinkhole hazard was also analysed theoretically with a new original model based on the solution of A. Sałustowicz’s pressure arch theory.

STUDI PERTUMBUHAN TANAMAN PADA AREAL PASCA TAMBANG DATARAN TINGGI DI KALIMANTAN SELATAN

This research purposed to analyze the growth of the plants on post-mining landbased on the different vegetation ages. The observation was conducted on post-mining area of PT. Antang Gunung Meratus (AGM) at South Hulu Sungai Regency, South Kalimantan. The data retrieval included high condition and diameter of the plants also the physical and chemical characteristics of soil on reclamation area which aged 1 year, 5 years, and 7 years. The dominant species which were in the research location was sengon, trembesi, and gmelina. The average of plants high age 1 year were sengon 1,99 m, trembesi 1,01 m, and gmelina 0,94 m. The average diameter 1 year plants were sengon 4,13 cm, trembesi 2,48 cm, and gmelina 2,70 cm. The average of plants high age 5 years were sengon 7,89 m, trembesi 7,94 m, and gmelina 8,04 m. The average of diameter 5 years plants were sengon 30,49 cm, trembesi 25,23 cm and gmelina 21,38 cm. The average of high growth and diameter of 7 years old sengon plants is 13,02 m, and is diameter 30,18 cm.Keywords: Post-mining; Growth; Sengon, Trembesi; Gmelina

Conditional Harmony: The Relations between Mining Company and Local People

Mining corporation plays a role as surrogate state since it takes after the state in its development agenda. One of the biggest coal mining companies in Indonesia, PT. KPC (Kaltim Prima Coal), has carried out several activities other than mining ones. The activities are manifested in CSR (Corporate Social Responsibility) programs. An obligation to recover post-mining area by KPC is already implemented in a program called PESAT (Integrated Cattle Farm) which is one of the CSR programs. The farm in the recovered post-mining area is developed as a social program for people living around the mining area. My research was carried out with qualitative approach. Participatory observation and interviews with people in the village of Swarga Bara, Kutai Timur, East Kalimantan, were used in collecting data. The result shows that the people living around the KPC is an active agent in responding the corporate lives. The local people, in fact, depend on the KPC’s social programs since the programs are in favor of local development and welfare. Nevertheless, the local people respond negatively toward programs which do not meet their needs

Colonisation of secondary habitats in mining sites by Labidura riparia (Dermaptera: Labiduridae) from multiple natural source populations

BackgroundOpen cast lignite mines, sand pits and military training areas represent human-made, secondary habitats for specialized xerothermophilous and psammophilous species. Rare species, including the earwig Labidurariparia, are found in high population densities in such sites. However, it is unknown from which sources colonisation took place and how genetic variation compares to that of ancient populations on natural sites.MethodsUsing nine microsatellite markers, we analysed genetic variation and population structure of L. riparia in 21 populations in NE Germany both from secondary habitats such as lignite-mining sites, military training areas and a potassium mining heap, and rare primary habitats, such as coastal and inland dunes.ResultsGenetic variation was higher in populations from post-mining sites and former military training areas than in populations from coastal or inland dune sites. Overall population differentiation was substantial (FST = 0.08; FʹST = 0.253), with stronger differentiation among primary (FST = 0.196; FʹST = 0.473) than among secondary habitats (FST = 0.043; FʹST = 0.147). Differentiation followed a pattern of isolation by distance. Bayesian structure analysis revealed three gene pools representing primary habitats on a coastal dune and two different inland dunes. All populations from secondary habitats were mixtures of the two inland dune gene pools, suggesting multiple colonization of post-mining areas from different source populations and hybridisation among source populations.DiscussionPopulations of L. riparia from primary habitats deserve special conservation, because they harbour differentiated gene pools. The majority of the L. riparia populations, however, thrive in secondary habitats, highlighting their role for conservation.Implications for insect conservationA dual strategy should be followed of conserving both remaining natural habitat harbouring particular intraspecific gene pools and secondary habitat inhabited by large admixed and genetically highly variable populations.

Monitoring of Ground Movements Due to Mine Water Rise Using Satellite-Based Radar Interferometry—A Comprehensive Case Study for Low Movement Rates in the German Mining Area Lugau/Oelsnitz

In terms of its history and complexity, the Lugau/Oelsnitz mining area is a representative example of many hard coal fields in Europe. The special characteristic, however, is the low water inflow and the associated long flooding process with corresponding low and long-ongoing ground movements. In order to ensure the long-term monitoring of ground movements in the future, an adapted and cost-effective concept based on modern methods should be implemented. The today widely used radar interferometry, is well established as a method but the results offer many possibilities for interpretation, which one should be aware of in order to derive reliable information. Presented are the results of a complex interferometric evaluation, based on Sentinel-1 data from different orbits, and an analysis of the spatiotemporal characteristic of ground movements. The focus of this paper is a detailed presentation of the workflow and an application-related interpretation of the results. The pool of methods used includes radar interferometry, but also spatiotemporal analysis and modeling. The overall objective of this comprehensive case study is to present the possibilities but also the limitations of the application of radar interferometry and to provide a perspective for future monitoring in post-mining areas.

Surface-dwelling soil macrofauna and ground beetles (coleoptera: carabidae) of metal post-mining spoil heaps–community composition and potential risk element bioaccumulation

ABSTRACT Spoil heaps arising from mineral ore mining and smelting are a potential source of air, water and soil’s metalliferous contamination. However, the importance of such man-made sites as biodiversity refuge for rare or endangered species is assuredly undoubted, as the natural habitats are in decline. It is questionable, how potential risk elements, including heavy metals and metalloids released into the environment of spoil heaps, affect this phenomenon, since just the soil fauna representatives are in close contact with contaminants. Surface-dwelling soil macrofauna, with special emphasis on the carabids, were surveyed at spoil heaps within two metal post-mining areas in Eastern Slovakia. Contents of potential risk elements, including heavy metals and metalloids, were determined in substratum and selected invertebrate taxa too. Iron and aluminium dominated in substratum at both localities, where the environmentally most hazardous elements As, Cd, Cu, Pb and especially Hg exceeded permissible limits. The highest concentrations of Al and Fe were also found in the invertebrates. Regarding Zn, Cd and Sb, soil macrofauna representatives figured as their macro-concentrators. Our results indicate that metal post-mining spoil heaps have the potential to offer suitable habitats, especially for psammophilous species and groups preferring sites with the bare soil and sparse vegetation.