Environment In Mining Area Research Articles

Environment monitoring of mining area with comprehensive mining ecological index (CMEI): a case study in Xilinhot of Inner Mongolia, China

ABSTRACT The monitoring and evaluation of environmental and ecological status in mining area is critical for effective mineral management guidance, and remote sensing is a cost-effective solution for covering a wide spatial area with high temporal frequency. However, the diverse landscape in mining areas presents a challenge for finding a suitable monitoring method. To address this challenge, this study proposes a remote sensing-based comprehensive mining ecological index (CMEI), which integrates vegetation greenness, soil wetness, urban heat, air quality and water quality indicators obtained from Landsat images and Moderate Resolution Imaging Spectroradiometer (MODIS) products. The integration is achieved through a principal component analysis (PCA) to encapsulate various aspects of the environment in opencast mining areas. The proposed CMEI was then applied to assess the performance of an ecological restoration project carried out in the Xilinhot coalfield in Inner Mongolia, China, over the past two decades. Our findings show that the overall ecological environment in the dumping sites and backfilling sites of Xilinhot coalfield has improved from a score of 0.15 in 2005 to 0.33 in 2020, according to the CMEI. Nevertheless, our study also highlights that some newly established dumping sites require further strengthening of management and maintenance measures. The CMEI presents a novel and effective approach for monitoring and evaluating the ecological environment in mining areas, and it can potentially be applied to assess the ecological environment of opencast mining areas globally.

Effect of soil compaction on hydraulic properties and macropore structure: Evidence from opencast mines in the Loess Plateau of China

Affected by heavy machinery, the soil compaction in the opencast coal mine area is serious, which will change the characteristics of soil macropores, then affect the soil hydraulic properties and damage the ecological environment in mining area. In this study, the disturbed soil samples from the dumping area of Pingshuo opencast coal mine of China were collected. The soil samples were processed in bulk density from 1.30 g·cm−3 to 1.70 g·cm−3, and the soil hydraulic properties were measured, and the soil macropore characteristics were obtained using computerized tomography scanning in laboratory. The path analysis method was applied to analyze the effect of macropore characteristics caused by compaction on soil hydraulic properties. Soil compaction resulted in severe effects on soil hydraulic characteristics and macropore properties. Under same soil suction, the water contents remained in soil decreased with increasing compaction. The explanatory variables (average Euler number (AEN), macropore throat number (MTN), and macropore fractal dimension (MFD)) were main determinants of soil-water characteristic curve (SWCC), and the indirect path coefficient of macroporosity. The effects of AEN and MFD on soil infiltration properties were relatively high. The bulk density of 1.4 g·cm−3 was a critical point of affecting macropore properties then affecting soil hydraulic properties, and some soil reclamation measures should be conducted to make bulk density < 1.4 g·cm−3 for compacted soil in opencast coal mining area. This study provides a basis for selecting technology of land reclamation and the subsequent monitoring and maintenance of soil quality in mining areas.

Stability Monitoring of Goaf Based on Remote Sensing Image

Large scale mining of coal resources is a major factor causing goaf collapse in China. According to the statistics of 21 major coal mining provinces, the area of coal mining surface subsidence is up to 4.5 billion m2, posing a great threat to the regional ecological environment and people's lives and property. The rapid development of remote sensing technology has changed the traditional field survey method and has become one of the important means of environmental monitoring. Information can be obtained not only by photography, but also by scanning. The amount of information obtained by remote sensing far exceeds that obtained by conventional traditional methods. Based on remote sensing images, this paper studies the stability monitoring of coal mine goaf, establishes a ground pressure monitoring network suitable for the actual situation of the mining area, and carries out long-term effective ground pressure monitoring. Through remote sensing images, we can fully grasp and avoid the hazards of the goaf. Remote sensing technology has the characteristics of wide use, large detection range, and rich information acquisition. It can comprehensively obtain the basic information of the mining area environment, and then monitor the mining area environment.

A Novel Mine-Specific Eco-Environment Index (MSEEI) for Mine Ecological Environment Monitoring Using Landsat Imagery

The excessive exploitation of mineral resources will lead to environmental pollution, resource depletion, environmental disaster, and other problems. The contradiction between the environment and development, and the management of the ecological environment in mining areas are urgent p-problems to be solved. An ecological environment assessment is an important part of the ecological environment in a mining area. The accurate evaluation of the ecological environment is the premise behind environmental governance in a mining area. However, current ecological assessment indicators were not developed specifically for mine environment monitoring and, thus, cannot provide an effective and comprehensive assessment of the mineral environment. To this end, in order to improve the environmental monitoring performance in mining areas, a novel Mine-Specific Eco-Environment Index (MSEEI) was proposed, integrating factors from five main aspects associated with minerals, including temperature, vegetation, soil moisture, atmospheric environment, and mining scale. Meanwhile, a widely concerned mine—Luanchuan mine—was used as the case area to test the performance of our MSEEI. The results showed a significant correlation between RSEI and MSEEI (p &lt; 0.01). The mean correlation achieved between RSEI and MSEEI was 0.91, which was much higher than the correlations between RSEI and enhanced vegetation index (EVI), soil moisture monitoring index (SMMI), normalized difference built-up and soil index (NDBSI), PM2.5 concentration (DI), and heat (LST). In addition, based on our long-term MSEEI results of Luanchuan mine from 1997 to 2021, the ecological status of Luanchuan mine showed a trend of first declining and then rising. Specifically, the MSEEI first declined from 0.85 to 0.77 between 1997 and 2012, and then rebounded to about 0.8 in recent years. The MSEEI exhibited a good applicability in the ecological assessment of mining areas. Our MSEEI can provide useful guidance for mine environment monitoring. MSEEI can directly reflect the ecological damage after mining, provide scientific guidance for the exploitation and utilization of mineral resources, and promote the protection and sustainable development of Earth’s resources and mine ecological environments.

Layered re-breaking behavior of gangue backfilling materials and inspirations for protecting mined ecological environments

Gangue backfilling mining technology plays an important role in relieving environmental problems in mining area. The compression deformation and particle re-breaking properties of backfilling material directly affect gangue backfilling effect. In this study, three-dimensional acoustic emission (AE) positioning for broken particle materials was used to reveal the internal particle re-breaking process for broken backfilling coal gangue. The results can be summarized as follows: the compression deformation stage significantly affected the AE amplitude evolution during compression. In the initial and linear compaction stages, it increased gradually until stabilization at 90–100 dB. After compression to the plastic compaction stage, the AE amplitude gradually decreased, showing a higher decrease at smaller particle size. During the entire compression stage, more than 90 % of the AE amplitude was concentrated around 40–59 dB. According to the AE positioning and particle re-screening results, broken coal gangue exhibited layered re-breaking characteristics, that is, the particle re-breaking first occurred in the middle layer and then gradually shifted to the upper and lower layers with the stress increased. Larger particles were more likely to re-break under the same stress. Increasing the compacting force and reducing particle size of gangue backfilling materials in the middle of the mining goaf are proposed to improve the gangue backfilling effect and protect the ecological environment of mining areas.

Response of plant element traits to soil arsenic stress and its implications for vegetation restoration in a post-mining area

The ecological environment in mining area is fragile, and the carbon (C), nitrogen (N), and phosphorus (P) content of dominant plants is closely related to plant nutrient limitation, community composition and ecosystem function. Clarifying the response of dominant plants to soil properties and the corresponding trade-off mechanism are essential for rebuilding the ecological resilience and self-sustaining ability of mining areas. In order to explore the response of dominant plant element traits to soil physico-chemical properties under the stress of soil arsenic (As) pollution, an abandoned metal mining area threatened by heavy soil As pollution was selected as the research area, the soil physico-chemical properties and soil As content in different speciation, and the contents of C, N and P in dominant plants were measured. The results showed that: (1) The soil As pollution was serious in the mining area, while the contents of soil nutrient were relatively low. (2) The soil As content in different speciation affected the absorption and utilization of P by plants. (3) The dominant plants responded to soil As toxicity by allocating more nutrients to leaves to reduce toxicity and ensure growth. This study helps to reveal the nutrient driving law of plant diversity processes and community succession in heavy metal-contaminated sites and is of great significance to restore the fragile ecosystems in mining areas.

Review on resource and environmental carrying capacity of mining areas in China

The excessive consumption of resources and the destruction of ecological environment in mining areas have severely restricted coal mining, and the research on resource and environmental carrying capacity (RECC) of mining areas is of great significance in reconciling coal mining and resource environmental protection. To review the existing research on the RECC of mining areas, the concepts of the RECC were elaborated, and then the development process and application areas of both resource carrying capacity (RCC) and environmental carrying capacity (ECC) were studied. The main methods and models involved in the RECC study were counted. The results showed that the research on the RECC of mining areas has not attracted sufficient attention, and the relevant literature is relatively few. The existing research on RECC in mining areas mainly adopts single-factor analysis, which makes it difficult to comprehensively evaluate the overall situation of RECC in mining areas. Thus, a comprehensive evaluation of the RECC of mining areas by scientific evaluation methods is required to ensure the coordinated development of coal production, resources and environment of mining areas. This review provides an important reference and guidance for the necessity and thinking of the comprehensive study of resources and environment carrying capacity in mining areas.

Assessing Potential Spontaneous Combustion of Coal Gangue Dumps after Reclamation by Simulating Alfalfa Heat Stress Based on the Spectral Features of Chlorophyll Fluorescence Parameters

The spontaneous combustion of coal gangue dumps after reclamation causes severe harm to the ecological environment surrounding mining areas. Using remote sensing technology to determine vegetation heat stress levels is an important way to evaluate the probability of a spontaneous combustion disaster. The canopy spectra and chlorophyll fluorescence (ChlF) parameters of alfalfa were collected through pot experiments to simulate different heat stress levels. Time series analyses of three ChlF (chlorophyll fluorescence) parameters showed that the regularity of the quantum efficiency of photosystem II (PSII) in light-adapted conditions (Fv′/Fm′) was stronger during the monitoring period. The correlation coefficients between the three ChlF parameters and the canopy raw spectrum, first derivative spectrum, and vegetation indices were calculated, and the spectral features were found to be more correlated. Lasso regression was used to further screen spectral features, and the optimal spectral features were the raw spectral value at 741 nm (abbreviated as RS (741)) and NDVI (652, 671). To discriminate among heat stress levels accurately and automatically, we built a time convolution neural network. The classification results showed that when the sequence length is 3, the heat stress is divided into three categories, and the model obtains the highest accuracy. In combination with relevant research conclusions on the temperature distribution law of spontaneous combustion in coal gangue dumps, three heat stress levels can be used to assess the potential of spontaneous combustion in coal gangue dumps after reclamation. The research results provide an important theoretical basis and technical support for early warnings regarding spontaneous combustion disasters in reclaimed coal gangue dumps.

A Field Study of Coal Fire Areas Re-Burning Behavior Assessment and Related Carbon Emissions

The re-burning of coal seams still occurs in coal fire areas after firefighting projects. A large amount of spontaneous combustion gas products is released from the surface fissure, which can cause air pollution and even threaten the production of surrounding mining areas. However, the distribution characteristics of fissure channels in the re-burning coal fire areas are local and scattered. Therefore, we developed a system for the in situ monitoring of spontaneous combustion gas emissions from fissure channels to conduct field investigations on the re-burning behavior of coal seams to explore the degree of re-burning in the coal fire area. The results showed that re-burning of the coal fire area induced fissure channels with different shapes. The CO2 concentrations are always higher than the CO concentrations among the spontaneous combustion gas products discharged from the fissure channels. The degree of re-burning of coal seams at different study locations was comprehensively determined using simplified MCE and CO2/CO ratios. The comprehensive factor α was obtained using the generalized principal component analysis (GPCA) by taking into account spontaneous combustion gas, meteorological factors, and the thermal physical characteristics of fissures. A carbon emission model for local fissure channels in the coal fire area was established, and the daily average carbon emissions at the study location were 2.56 t. Therefore, this provides essential theoretical support for taking corresponding fire extinguishing measures according to the degree of re-burning of the coal fire area.

Research Progress of Land Reclamation in Mining Areas in China

The ecological environment of mining area is an important problem that affects the sustainable development of mining area and regional ecological security. The mining industry has promoted the global economic development, but also caused a series of ecological degradation. Ecological restoration of mining areas has become an urgent problem for all countries in the world. This paper expounds the research technology and development trend of ecological restoration in mining areas in China, and looks forward to the ecological restoration in mining areas in the future, which will provide reference for the ecological restoration of mining land reclamation in the future.

Regional metal pollution risk assessment based on a big data framework: A case study of the eastern Tianshan mining area, China

With the increasing maturity of big data technology, its application in the field of environmental assessment has become an important issue. The mining of mineral resource can affect the balance in the ecological environment surrounding mining areas and the normal life activities of humans through groundwater. To solve this problem, big data-based methods were used to evaluate the pollution risk in mining areas in this article. Based on a spatial big data management framework, in this paper, high-risk areas in eastern Tianshan were quantitatively analyzed and delineated via a new comprehensive heavy metal pollution assessment system. A distributed storage environment, unstructured management method and spatial index coding were used to uniformly manage spatial data in vector and raster formats retrieved from different sources. A system involving 18 geological environment indicators was used to evaluate the risk level in the study area and in delineated areas with a high risk of heavy metal pollution. The results indicated that the proposed framework could efficiently store and process spatial data and realize environmental pollution risk assessment in a big data environment. In addition, some of the high-pollution risk areas identified based on the assessment results were consistent with actual mine locations. Overall, the results show that integrating multi-source geological characteristics through a comprehensive evaluation system based on big data can have a positive effect on improving the accuracy of heavy metal pollution risk assessment. Heavy metal pollution assessment can provide a reference for environmental monitoring and governance of the eastern Tianshan region and offer new solutions to large-scale heavy metal pollution assessment.

An Analysis of the Impact of E-Commerce Supply Chain Collaboration on the Ecological Environment in Central Plain

Abstract In recent years, the ecological environment has been severely damaged and has evolved into a problem threatening human health due to the construction of the ecological environment. Therefore, studying the eco-environmental (ecological environment) issues in the process of the new eco-environment is of great significance to the comprehensive development of the region. The basic research framework of this article is to ask questions, analyse problems and solve problems. With the rise of e-commerce media platforms as the background, we use case studies and in-depth interviews to discuss the characteristics of the ecological crisis of e-commerce media platforms and analyse them in depth. This paper takes the new ecological environment as the research background, selects six major cities in the Central Plains as the research objects, and digs deep to find out the current ecological and environmental problems in the Central Plains. By citing the PSR (Pressure-State-Response) model, we construct the initial pressure and use the factor analysis method to determine the evaluation index model of the 16 sub-indices. Finally, we use the entropy method to standardise the original indicators. We determine the index weights, etc., to analyse the level of the ecological environment of the six cities. At the same time, this article evaluates the ecological environment in the process of the new ecological environment in the Central Plains. First, an evaluation index system is established, and then the evaluation index weight is determined to obtain the order of the ecological environment problems. According to the total score value of ecological environment quality, for different areas, comprehensive ecological environment zoning is proposed so that resources can be better and rationally developed and utilised. The ecological environment of mining areas is protected and improved to the maximum extent. At the same time, the mine ecological environment monitoring work plan is formulated; the construction of ecological restoration is proposed for areas (mine parks, geological parks, forest parks, and ecological parks). Through organisational structure adjustment and overall supply chain optimisation, relevant feasible solutions are proposed, and examples are given to illustrate the optimisation effects; the part summarises the significance of this research and the main existing problems and proposes future research recommendations. In the context of the new ecological environment, analysing the current situation of the ecological environment in the Central Plains, identifying the ecological and environmental problems in the process of the ecological environment, and proposing corresponding solutions based on the problems are conducive to the development of the new ecological environment in the Central Plains.

Co-catalytic effect of WS2 on the copper slag mediated peroxodisulfate activation for the simultaneous elimination of typical flotation reagent benzotriazole and Cr(VI)

In this study, efficient simultaneous elimination of typical mine pollutants benzotriazole (BTA) and Cr(VI) was achieved by using a copper slag (CS) activated peroxodisulfate (PDS) Fenton system, with WS2 as a co-catalyst. The combined use of these two mine-sourced materials enables excellent pollution removal efficiency. CS can continuously release ferrous ions for the advanced oxidation processes (AOPs), while WS2 as a co-catalyst has key roles in acceleration of the rate-limiting step of Fe3+/Fe2+ conversion and prevention of Fe3+ precipitation. In this process, Fe3+/Fe2+ conversion primarily occurs on the surface of WS2, whereas PDS decomposition and BTA degradation are dominated by homogeneous Fenton reactions. Dissolved Fe2+ has a main role in the activation of PDS and generation of ROS. The contributions of free radicals, singlet oxygen and Fe(IV) in BTA degradation were carefully evaluated. Fe(IV) was identified as the major ROS responsible for degradation of BTA in the CS/WS2/PDS system. This was further confirmed by the Raman spectra and the detection of BTA degradation products formed by the transfer of oxygen atoms. Kinetics calculation showed that Fe(IV) was responsible for 63.4 % of the degradation of BTA. More importantly, water matrix had a low impact on the degradation of BTA due to the high selectivity of Fe(IV). This study provides a new strategy for a cost-effective and efficient decontamination of the environment in mining areas.

A Monitoring System for Air Quality and Soil Environment in Mining Areas Based on the Internet of Things

In order to solve the intensifying problem of heavy metal pollution of soil in mining areas, a method for monitoring air quality and soil environment in mining areas based on the Internet of Things is proposed. Using meta-analysis method and health risk assessment method, the impact of mining on soil heavy metal content in Southwest China was quantitatively analyzed, and the relationship between soil heavy metal value and its potential influencing factors was discussed, as well as the heavy metal pollution, ecological risk, and health caused by soil mining activities. Risks were assessed. The results showed that artificial and oral intake were the main modes of soil heavy metal exposure, with the highest daily intakes for noncarcinogenic risk children and the highest daily intakes for carcinogenic risk adult females. The noncarcinogenic risk (HQ&gt;1) of soil As and Pb exposure to children was 3.74 and 1.44, respectively. The carcinogenic risk values of As, Cd, Cr, and Ni in soil were all higher than 10-6, indicating that the carcinogenic risk was within the tolerance range of human body. Children were exposed to the combined noncarcinogenic risk ( HI = 3.83 ), and the risk values of the three types of recipients were 1.19 × 10 − 4 , 1.21 × 10 − 4 , and 1.06 × 10 − 4 , respectively. The correlation between heavy metal content and environmental factors was obtained. It is verified that the system in this paper can effectively monitor the meteorological environment and soil environment, and at the same time, it reveals the pollution law of heavy metals in the soil of the mining area, which provides supporting conditions for future mining and heavy metal pollution management.

Landscape Analysis of Cobalt Mining Activities from 2009 to 2021 Using Very High Resolution Satellite Data (Democratic Republic of the Congo)

The cobalt mining sector is well positioned to be a key contributor in determining the success of the Democratic Republic of the Congo (DRC) in meeting the Sustainable Development Goals (SDGs) by 2030. Despite the important contribution to the DRC’s economy, the rapid expansion of mining operations has resulted in major social, health, and environmental impacts. The objective of this study was to quantitatively assess the cumulative impact of mining activities on the landscape of a prominent cobalt mining area in the DRC. To achieve this, an object-based method, employing a support vector machine (SVM) classifier, was used to map land cover across the city of Kolwezi and the surrounding mining areas, where long-term mining activity has dramatically altered the landscape. The research used very high resolution (VHR) satellite imagery (2009, 2014, 2019, 2021) to map the spatial distribution of land cover and land cover change, as well as analyse the spatial relationship between land cover classes and visually identified mine features, from 2009 to 2021. Results from the object-based SVM land cover classification produced an overall accuracy of 85.2–90.4% across the time series. Between 2009 and 2021, land cover change accounted to: rooftops increasing by 147.2% (+7.7 km2); impervious surface increasing by 104.7% (+3.35 km2); bare land increasing by 85.4% (+33.81 km2); exposed rock increasing by 56.2% (+27.46 km2); trees decreasing by 4.5% (−0.34 km2); shrub decreasing by 38.4% (−26.04 km2); grass and cultivated land decreasing by 27.1% (−45.65 km2); and water decreasing by 34.6% (−3.28 km2). The co-location of key land cover classes and visually identified mine features exposed areas of potential environmental pollution, with 91.6% of identified water situated within a 1 km radius of a mine feature, and vulnerable populations, with 71.6% of built-up areas (rooftop and impervious surface class combined) situated within a 1 km radius of a mine feature. Assessing land cover patterns over time and the interplay between mine features and the landscape structure allowed the study to amplify the findings of localised on-the-ground research, presenting an alternative viewpoint to quantify the true scale and impact of cobalt mining in the DRC. Filling geospatial data gaps and examining the present and past trends in cobalt mining is critical for informing and managing the sustainable growth and development of the DRC’s mining sector.

Surface Environmental Evolution Monitoring in Coal Mining Subsidence Area Based on Multi-Source Remote Sensing Data

The exploitation of mineral resources is crucial for cost-effective construction but has also led to severe damage to the ecological environment in mining areas. Therefore, it is particularly important to effectively monitor surface environmental problems in the mining subsidence area caused by the exploitation of mineral resources. Herein, the Huinong coal mining subsidence area, Shizuishan city, Ningxia, China, was taken as the study area. The remote sensing image features of various environmental elements were investigated through field investigations, the measured spectra, and image spectrum contrast analysis. On this basis, an object-oriented random forest classification method was used to classify images from different time phases and sources in coal mining subsidence areas. Next, the man–machine interactive interpretation was confirmed by referring to the pre-classification results. By overlaying the interpretation result map and analyzing the land-use class changes, the spatial–temporal evolution monitoring of the surface environment in the coal mining subsidence area from 1979 to 2018 was carried out. The results show that the surface environment in the coal mining subsidence area has undergone significant changes over the past 40 years, among which—from 1979 to 2003—the environment of the coal mining area was severely damaged by the intensive mining activities. The area of cultivated land and vegetation coverage decreased sharply, while the area of other land-use classes, such as coal heaps, water bodies, and coal gangue, exhibited a trend of rapid growth. From 2003 to 2018, after more than 10 years of mine geological environment renovation and management, the surface environment of the coal mining subsidence area greatly improved, among which the vegetation coverage has shown the fastest growth rate, while the area of coal gangue, badlands, and other land-use classes have significantly reduced. The hidden dangers of geological disasters have been drastically mitigated. In addition, the residential area continued to decrease in the early stages and then rebounded to a certain extent, indicating that urbanization was carried out at the same time as the ecological environment began to improve. The surface environment before and after the renovation is consistent with the results from remote sensing monitoring.

Microscopic fabric evolution and macroscopic deformation response of gangue solid waste filler considering block shape under different confining pressures.

The irregular shape of gangue blocks will affect the coordination structure between blocks in the crushed gangue accumulation body, and then affect the engineering mechanical properties of crushed gangue in the process of load-bearing compression. In this paper, through CT scanning experiment, particle flow numerical simulation experiment, and comprehensive application of image processing, 3D reconstruction, FLAC/PFC3D continuum—discrete coupling technology, the gangue digital 3D model and the numerical model of crushed gangue particle flow under triaxial compression condition considering the real shape of the block were obtained. The microscopic fabric evolution law and macroscopic deformation response characteristics of crushed gangue considering triaxial compression condition and different confining pressures were studied. The results show that: (1) the bearing capacity of crushed gangue materials increases with the increase of confining pressure; (2) the block aggregate in the gangue sample is gradually compacted, and the lateral deformation of the sample is changed from “extruding to the axis” to “bulging to the periphery”; (3) the vertical movement of the block decreases gradually from the top to the bottom of the sample, and there is a “triangle area” of block displacement at the top and bottom of the sample; the larger the confining pressure, the smaller the vertical displacement range at the top of the sample; (4) the process of “instability and failure—optimization and reconstruction” of skeleton force chain structure occurs constantly; as confining pressure increases, the stability of skeleton force chain structure and the bearing capacity of crushed gangue sample increases; (5) under the same strain state, the greater the confining pressure, the higher the fragmentation degree of the sample. This study reveals the internal mechanism of macro deformation of crushed gangue under the triaxial compression from the perspective of the mesoscopic fabric evolution. The research results are of great significance for the selection of crushed gangue in engineering application. In addition, the research results also have a significant impact on promoting the reasonable disposal and resource utilization of gangue solid waste and protecting the ecological environment of mining areas.

Evaluation of resource and environmental carrying capacity in rare earth mining areas in China

Rare earth elements are a nonrenewable and important strategic resource, and China is rich in these elements. However, the substantial exploitation of these resources has caused the migration, diffusion, transformation and accumulation of pollution sources, which in turn has a profound impact on the ecological environment of mining areas. Accurate evaluations of resource and environmental carrying capacity (RECC) are important for the green development of mining areas. In this paper, the fuzzy comprehensive evaluation method based on the combination of the AHP (Analytic Hierarchy Process) and entropy methods is used to study the RECC of mine areas in terms of both support capacity and pressure. The Bayan Obo mine in Inner Mongolia, the Longnan mine in Jiangxi, the Weishan mine in Shandong, the Mianning mine in Sichuan, the Pingyuan mine in Guangdong, and the Chongzuo mine in Guangxi, which are typical representative mines, were selected for a horizontal comparison. The results show that, with the exception of the Bayan Obo mine, the support index was greater than the pressure index in terms of mining and human activities in all mining areas. The RECC index ranked order for the mining areas was Bayan Obo > Longnan > Mianning > Pingyuan > Weishan > Chongzuo. In addition, an obstacle degree model was used to identify and extract the main factors affecting the ecological quality of the mine sites. The ratio of investment in environmental pollution control to GDP was the most important factor, of all factors, which limited the improvement in the mine support index. Through the above research, we identified the main factors affecting the ecological carrying capacity of each mining area, providing a scientific basis for formulating corresponding environmental regulations and reducing the environmental pollution caused by rare earth mining.

Quantitative remote sensing-based monitoring and evaluation of the ecological environment in mining areas: technology framework and application

Quantitative remote sensing-based monitoring and evaluation of the ecological environment in mining areas: technology framework and application

Vegetation restoration restricts rill development on dump slopes in coalfields

Severe rill erosion on dump slopes poses a great threat to the ecological environment in mining areas. Vegetation restoration is an effective measure for controlling soil erosion on dump slopes. However, few studies have identified the long-term influence of vegetation restoration on rill development on dump slopes. Therefore, we investigated the rill development characteristics of dump slopes with three typical restoration models (CK: natural restoration; ED: Elymus dahuricus; and AO: Artemisia ordosica) and three recovery time (1 y, 3 y and 5 y). The results showed that vegetation adequately controlled rill erosion on dump slopes. ED and AO could effectively control the development of rills with widths >15 cm and depths of 10–20 cm. ED vegetation restoration inhibited the development rill morphology and network better than AO. The rill erosion modulus of the ED slope and AO slope decreased by 76.29%–90.77% and 46.66%–61.49%, respectively, compared with that of natural restoration slopes with recovery time of 1 y, 3 y, and 5 y. ED controlled rill erosion better than AO, but this effect gradually weakened with recovery time. Vegetation coverage contributed 34.99% of the total variation in rill morphology and was the main factor affecting the development of rills on dump slopes. Furthermore, vegetation coverage had a more important role in controlling rill development than did the root system on dump slopes. This study provides valuable information for optimizing vegetation construction for soil loss control on dump slopes.