Coal Mining Activities Research Articles

Pengaruh Tandan Kosong Kelapa Sawit pada Media Buatan terhadap pH, Fe, dan Mn untuk Pengelolaan Air Asam Tambang

Indonesia is a coal producing country and coal mining activities are carried out using the open pit method. The activity resulted in the acid mine drainage (AMD). AMD has low pH and contains high concentrations of heavy metals ions such as aluminum (Al), iron (Fe) dan manganese (Mn). One of the interesting technologies in the AMD treatment is passive treatment using constructed wetland. The system can increase pH and reduce level of dissolved metals. Oil palm empty fruit bunches (OPEFB) are potential to improve soil pH, because they have a high nutrient content such as N, P, and K. This study aims to determine the effect of OPEFB as amendment material on artificial wetland media on pH, Fe, Mn in AMD management. The method used was a single Randomized Complete Design with the treatment of OPEFB of 0, 100, 200, 300, and 500 g 5.5 kg-1 soil then replicated four times. The results showed that oil palm empty fruit bunches high significant increase in pH, Fe, Mn and 100 g 5.5 kg-1 soil doses effectively used for the AAT management by passive treatment as fulfilled the mining liquid waste quality standards according to the Ministerial Decree State of the Environment Number 113 of 2003 and South Kalimantan Province Governor Regulation Number 04 of 2007.

Biochar application stabilized the heavy metals in coal mined soil

The waste of coal mining activities causes accumulation of hazardous elements in soil for plants. Biochar is considered an important soil remediation strategy to stabilize the heavy metals. The aim of this study was to quantify the effect of biochar sources and rate on the heavy metal stabilization in coal-contaminated soil. Biochars of three feedstocks (maize straw (MBC), rice straw (RBC), and sugarcane bagasse (SBC)) with four levels (0%, 0.5%, 1%, and 2%, i.e., 0, 10, 20, and 40 ton ha−1) were applied to two types of soils (naturally contaminated soil (NCS) versus artificially contaminated soil (ACS) spiked with Cd, Cu, Cr, and Pb). Plastic pots were incubated at 30% field capacity for 90 days at 25 °C, and soil pH, electrical conductivity (EC), and heavy metals concentration were measured after 1, 4, 8, and 12 weeks. Among the biochars, RBC showed maximum immobilization of Cd, Pb, Cu, and Cr as compared with MBC and SBC. Similarly, biochar application increased heavy immobilization, being maximum at 2% (40 ton ha−1) rate compared with control. The pH of both soils with biochar addition increased as compared with control. The remediation effect of biochar on heavy metal stabilization was positive over time. The higher rate (40 ton ha−1) of RBC for ACS and MBC for NCS could be used effectively for heavy metal stabilization.

MFPA-Net: An efficient deep learning network for automatic ground fissures extraction in UAV images of the coal mining area

Ground fissures caused by high-intensity underground coal mining activities will damage the ecological environment and endanger mine safety. The complicated surface conditions in coal mining areas make fissure detection labor-intensive work, and manual fissure extraction is inefficient, restricting the surface monitoring work. In this study, an efficient Deep Learning (DL) network named MFPA-Net (Multi-scale Feature Pyramids and Attention Network) is proposed to extract ground fissures in Unmanned Aerial Vehicle (UAV) images from the coal mining area automatically and accurately. In MFPA-Net, the Dilated Residual Networks (DRN) are used to extract diverse context information, the Dual Attention Mechanism (DAM) is introduced to integrate the dependence of pixels' spatial location and feature channels to generate high-level features, the Atrous Spatial Pyramid Pooling (ASPP) is utilized for mining multi-scale context information from high-level features, and the Multi-scale Feature Pyramid Network (MFPN) is designed to combine high-level and low-level features. Moreover, the Focal Tversky Loss Function is adopted to handle the unbalanced samples. To promote DL technologies application in the fissure monitoring of mining areas, the GFCMA (Ground Fissures of the Coal Mining Area) dataset is constructed. Experiments on GFCMA show that MFPA-Net can achieve high Precision (69.4%), Recall (70.7%), F1-Score (70.0%), and Mean Intersection over Union (MIoU) (75.1%) simultaneously, which significantly outperform traditional image processing methods and recently DL networks. Experiments on public pavement datasets Crack500 and DeepCrack prove MFPA-Net's high reliability and widespread applicability. The performance of the trained MFPA-Net on real large-scale scenarios demonstrates its practical value, strong robustness, and high efficiency. This study provides a solution for rapid monitoring of ground fissures under complicated surface conditions, which can serve the safe production and ecological restoration high-efficiently in mining areas.

Hydrogeochemical characteristics and solute sources of groundwater in the Yuhengbei mining area, Shaanxi Province, China

In mining areas, groundwater resources are crucial for providing drinking water, as well as water needed for plant growth and mining. The Yuhengbei mining area is situated in arid and semi-arid areas in Western China. As there are a number of large-scale mining fields in the area, their exploitation may affect both the quality and quantity of groundwater. The hydraulic connection between aquifers directly determines whether deep coal mining activities affect water quality in shallow aquifers. This study investigates the hydrogeochemical characteristics and the solute sources of groundwater (including surface water, Quaternary water, water from Cretaceous and Jurassic coal strata aquifer) in the Yuhengbei mining area. The study uses conventional, multivariate statistical analysis, and dissolved organic matter (DOM) analysis. The results suggest that all water samples were slightly alkaline, while the water from the shallow aquifers (surface water, Quaternary and Cretaceous aquifers) was predominantly of the HCO3-Ca type. Furthermore, the groundwater in the deep Jurassic aquifer was mostly of the SO4-Na type. Major ion and DOM concentrations appeared to decrease with increasing aquifer depth. Moreover, the groundwater circulation is regulated by natural processes. Namely, rock weathering was the main mechanism controlling the chemical constituents of groundwater in the shallow aquifers, while groundwater quality in deep aquifers was mainly governed by the dissolution of evaporation. Water–rock interaction and cation exchange were the main mechanisms controlling the chemical constituents of groundwater. The R-mode HCA revealed that natural processes controlled the chemical composition of groundwater, as well as that the evolution of groundwater is primarily controlled by the nature of the geological structures and the local hydrogeological conditions. The TOC and UV254 results suggest that the coal strata aquifer had a weak hydraulic connection with the overlying aquifers. The DOM was mainly derived from autogenous biological sources. Based on the indicator values, the hydraulic connection between the deep aquifers and the upper shallow aquifers was weak overall. These results show that in this area, although drinking water and irrigation water come predominantly from shallow groundwater, mining activities temporarily have little impact on the quality of shallow groundwater. Better understanding hydrogeochemical characteristics and formation mechanisms will provide a technical basis for local groundwater management and support the sustainable use of water resources.

A Low-Cost Web Application System for Monitoring Geometrical Impacts of Surface Subsidence

This paper develops a low-cost web application system for monitoring geometrical impacts of surface subsidence. In many of the developing countries, the method of extraction of minerals such as coal is often impractical and uneconomical, especially with surface mining. With global warming, rapid population growth, and fast-growing urbanization with a disregard for sustainability, the overall subsidence risk has significantly increased. Despite the maturity of Differential Interferometric Synthetic Aperture Radar (DInSAR) for timely monitoring of subsidence hazards, the potential of SAR constellations has been under-exploited, as most applications focus mainly on mapping unstable areas. The developed web application system exploits Sentinel-1 SAR constellation and Small-BAseline Subset (SBAS-DInSAR) technique, to provide new streamlines of information for monitoring solutions and improve disaster risk decision making. We illustrate the model by investigating and measuring potential surface subsidence caused by underground hard coal mining activities and exponential urban population growth within a major coalmine in Nigeria. Results of the yearly cumulative amount of horizontal and vertical deformation between 2016 and 2020 range from −25.487 mm to −50.945 mm and −24.532 mm to −57.161 mm, for high and low risks, respectively. Under the influence of external factors such as rising poverty and fast-growing urbanization, the destruction of in situ stress distributions will likely increase nonlinear deformations.

Analysis of Formation Mechanism of Slightly Inclined Bedding Mudstone Landslide in Coal Mining Subsidence Area Based on Finite–Discrete Element Method

In this paper, the formation mechanism of a slightly inclined bedding mudstone landslide in the overlying mountain of the coal mining subsidence area of the Tanshan Coal Mine in Ningxia, China, is studied. By means of geotechnical investigation, indoor geotechnical tests, theoretical analysis and other technical means, we find the geological environment background of the study area and obtain the physical and mechanical property indexes of the mining landslide in the Tanshan Coal Mine. By combining the numerical simulation of discrete elements and finite elements, the macro deformation and failure law of the mining mudstone landslide and the displacement and stress nephogram of the failure process are discussed. The results show that the slightly inclined bedding mudstone landslide in the Tanshan Coal Mine is 850 m long from east to west, 500 m wide from north to south and 10,875,000 m3 in volume. It is composed of Jurassic mudstone and is a traction landslide caused by the coal mining subsidence area. The formation of the landslide is affected by internal factors and inducing factors. The internal factors are mainly geotechnical types and engineering geological properties, and the inducing factors are mainly coal mining activities and rainfall. By analyzing and summarizing the calculation process of the slope model prior to the landslide in 2D-Block and GeoStudio numerical simulation software, the sliding process of the slightly inclined bedding mudstone landslide in the Tanshan Coal Mine is divided into four stages: slope creep, slope deformation, landslide movement and landslide accumulation. GeoStudio software is used to calculate the stability of the Tanshan Coal Mine landslide under natural and rainfall conditions. The landslide is in a stable state under natural conditions and is basically stable under rainfall conditions. By comparing the calculation results of the limit equilibrium method and the finite element limit equilibrium method, we find that the calculated stability coefficient is more accurate when the appropriate constitutive model is selected. The research results have important reference significance for the prevention and control of the gently inclined bedding mudstone landslide of the overlying mountain in the coal mining subsidence area of the Loess Plateau.

Health Risk Assessment of Children Exposed to the Soil Containing Potentially Toxic Elements: A Case Study from Coal Mining Areas

Coal mine activities lead to the release of potentially toxic elements (PTEs) to the surrounding areas. The present study concerns the health risk caused due to the exposure of PTEs (Hg, As, Cd, Cr, and Pb) in the children residing in the areas around coal mines. The PTEs content and bioaccumulation coefficient (BAC) in the plant, viz., Albizia lebbeck and Madhuca longifolia growing on the nearby soils of the coal mine affected areas were also estimated. The results demonstrated that the hazard quotient (HQ) for Cr (0.211) in the roadside soil (RSS) was higher than other PTEs. The hazard index (HI) was also at the maximum in the RSS (0.553) followed by the core zone soil (0.541). In RSS, Cr contributed the maximum for the HI value (38%) which elucidated that Cr might cause health problem in the long term. The Cr concentration (5.49 mg kg−1) was also higher than other PTEs in the plant leaves of M. longifolia and was two-fold higher than A. lebbeck. Except Cd, the accumulation of other PTEs in the leaves of both the species were low, which could be due to their low availability in soils. The BAC for Cr in M longifolia was comparatively higher than A. lebbeck and was found at the maximum for Cd (0.29) in M longifolia. The outcomes of the study elucidated that although there is no severe health risk in children, the data indicated that the prolonged exposure to PTEs might lead to serious health issues.

Identification of mixing water source and response mechanism of radium and radon under mining in limestone of coal seam floor

With the gradual increase of the coal mining depth, the mixing of multiple water sources intensifies and the activity of radium and radon in groundwater increases. Identifying the source of mine water inrush by using radium and radon isotopes is a new choice. In this paper, the mathematical statistics method, radioactive isotope decay theory, the mass conservation principle, and the numerical simulation method are used to analyze the influence of total dissolved solids (TDS), pH, and the hydrochemical ion content in groundwater on the isotope activity of radium, radon, uranium, thorium, and lead. The activity of thorium and lead is lower than the detection limit of the instrument, and the influence of coal mining activities on it is small. The simulation of the radium–radon mass balance in groundwater shows that the greater the adsorption coefficient (k) of solid particles in groundwater is, the more obvious the adsorption effect and the greater the influence on the radium–radon activity balance are. The radium–radon dating method is used to calculate the groundwater age. Results show that the groundwater age in the closed pit coal mining area is generally older than that in the mining coal mining area. Combined with the 222Rn, 226Ra, and 234U radioactive isotopes and temperature, a mixing water source identification model of limestone in the coal seam floor is constructed. The model shows that the radium activity and temperature of the groundwater are inversely proportional to the mixing ratio of the Permian sandstone water. From the closed pit coal mining area to the mining coal mining area, the radium radon activity of the groundwater increases gradually, the groundwater age decreases significantly, the water cycle is accelerated, the mixing ratio of the Permian sandstone water decreases gradually, the mixing ratio of the Ordovician limestone water increases gradually, and the risk of coal mine water inrush increases. The research results prove the feasibility of the new method for accurately discriminating the mixing water sources in coal mine areas, which is of great significance to the improvement of the theory of coal mine water disaster prevention and control.

Spatial–temporal variation analysis of water storage and its impacts on ecology and environment in high‐intensity coal mining areas

AbstractIn common with other important coal bases in northwestern China, the hydrology and ecology and environment of Ordos, northern Shaanxi (Shanbei), and Shanxi Provinces have much. Terrestrial water storage anomaly (TWSA), soil moisture anomaly (SMA), and groundwater storage anomaly (GWSA), are important water storage qualities that play a critical role in the distribution and growth of vegetation. In this paper, multi‐source remote sensing data were used to analyze the spatial–temporal changes and relationships of water storage, ecology and environment from 2002 to 2020. The numerical results showed the TWSA and GWSA in the study area had a declining trend and the rates were −7.512 mm yr‐1 and −8.268 mm yr‐1, respectively. On the contrary, the SMS showed an increasing trend, and the rate was 0.840 mm yr‐1. By trend variation and correlation analysis, we found GWSA is the main part in the variation of TWSA. By further analysis, it was found that the climate factors are not the major factors causing the variation of GWSA, but coal mining and artificial irrigation activities, which are especially clear in the Taihang Mountains in eastern Shanxi Province. The ecology and environment have been improving, and water storage and climate factors have played a different role in different regions. The warm climate conditions and the increased 0–40 cm of soil water have promoted the growth of vegetation and the improvement of the ecology and environment. The research results are helpful to understand the impacts of water storage on the ecology and environment in high‐intensity coal mining areas.

Quantitative identification of nitrate and sulfate sources of a multiple land-use area impacted by mine drainage

The rapid increase in urbanization and intensive coal mining activities have accelerated the deterioration of surface water quality. Environmental problems caused by the accumulation of nitrate and sulfate from natural, urban, and agricultural sources have attracted extensive attention. Information on nitrate and sulfate sources and their transformations is crucial for understanding the nitrogen and sulfur cycles in surface water. In this study, we monitored nitrate and sulfate in three representative rivers in mining cities in northern China. The main pollution sources and biogeochemical processes were identified by using stable isotopes (δD, δ18OH2O, δ15N, δ18ONO3, δ34S and δ18OSO4) and hydrochemistry. The contribution of natural and anthropogenic sources was quantitatively estimated based on a Bayesian mixed model. The results indicated a large variation in sulfate and nitrate sources between the different rivers. Nitrate in the Tuohe River mainly derived from manure/sewage (57.9%) and soil N (26.9%), while sulfate mainly derived from manure/sewage (41.7%) and evaporite dissolution (26.8%). For the Suihe River, nitrate was primarily sourced from chemical fertilizer (37.9%) and soil nitrogen (34.8%), while sulfate was mainly sourced from manure/sewage (33.1%) and chemical fertilizer (21.4%). For the Huihe River, nitrate mainly derived from mine drainage (56.6%) and manure/sewage (30.6%), while sulfate predominantly originated from mine drainage (58.3%) and evaporite dissolution (12.9%). Microbial nitrification was the major pathway for the migration and transformation of nitrate in the surface water. However, denitrification and bacterial sulfate reduction (BSR) did not play a significant role as aerobic conditions prevailed. In this study, we elucidated the sources and transformation mechanisms of nitrate and sulfate. Additionally, we provided a reference for formulating a comprehensive strategy for effective management and remediation of surface water contaminated with nitrate and sulfate in mining cities.

Investigation of the Distribution of Heavy Metals in the Soil of the Dahuangshan Mining Area of the Southern Junggar Coalfield, Xinjiang, China

Coal mining activities have a series of impacts on the local eco-environment, such as air pollution due to the release of toxic gases, contamination of soil with heavy metals, disturbance and contamination of surface and subsurface water, and damage to land resources with surface subsidence and accumulation of solid waste materials. This study investigated the distribution of heavy metals in mining sites by analyzing the heavy metal content in soil samples from different sites in the Dahuangshan mining area of the southern Junggar coalfield (Xinjiang, China). The results show that area C has the highest Cu content; and area B has the highest Mn content, the highest Zn content, the highest As content, and the highest Cd content, which indicate that area B underwent potential multiple heavy metal contamination. It also shows that the Cd is the major heavy metal for all three areas. The different eco-environmental indices, including the Nemerow comprehensive pollution index, the geo-accumulation index, and the potential ecological risk index, all show the same results, i.e., that Cd is the major potential contaminant in all three types of soil.

Coal Mining Activities Driving the Changes in Microbial Community and Hydrochemical Characteristics of Underground Mine Water.

Coal mining can cause groundwater pollution, and microorganism may reflect/affect its hydrochemical characteristics, yet little is known about the microorganism’s distribution characteristics and its influence on the formation and evolution of mine water quality in underground coal mines. Here, we investigated the hydrochemical characteristics and microbial communities of six typical zones in a typical North China coalfield. The results showed that hydrochemical compositions and microbial communities of the water samples displayed apparent zone-specific patterns. The microbial community diversity of the six zones followed the order of surface waters > coal roadways > water sumps ≈ rock roadways ≈ goafs > groundwater aquifers. The microbial communities corresponded to the redox sensitive indices’ levels. Coal roadways and goafs were the critical zones of groundwater pollution prevention and control. During tunneling in the panel, pyrite was oxidized by sulfur-oxidizing bacteria leading to SO42− increase. With the closure of the panel and formation of the goaf, SO42− increased rapidly for a short period. However, with the time since goaf closure, sulfate-reducing bacteria (e.g., c_Thermodesulfovibrionia, Desulfobacterium_catecholicum, etc.) proportion increased significantly, leading to SO42− concentration’s decrease by 42% over 12 years, indicating the long-term closed goafs had a certain self-purification ability. These findings would benefit mine water pollution prevention and control by district.

Stability Influencing Factors and Control Methods of Residual Coal Pillars with Solid Waste Materials Backfilling Method

Affected by coal mining activities, the remaining coal pillars are very likely to be destabilized and cause safety accidents. The backfilling of the remaining goaf can maintain the stability of the coal pillar well, but the coal pillar in the unfilled zone may still be unstable. In this paper, the effect of backfilling materials on coal pillars and the reinforcement method are discussed using numerical simulation, statistical mathematics, elastic mechanics, and mechanical test methods. The results show that: backfilling with solid waste materials and reinforcing the coal pillar could maintain the stability of the bottom goaf, where the backfill body height is the main factor in the strength of the coal pillar. The propagation of the confining stress of the backfill body on the pillar in the unfilled zone is the primary way to influence the coal pillar strength. Changing the backfill body height filling can affect the coal pillar strength. By analyzing the propagation law of confining stress in the coal pillar, the minimum backfill body height is determined to be 7 m. Combined with mechanical tests and the Mohr–Coulomb criterion, the minimum confining pressure required to maintain the coal pillar stability under the peak ground pressure is analyzed. The ratio of solid waste materials is determined based on this. Field tests have proved that the coal pillar remains stable when the goaf is not filled, and the cement/fly ash ratio is 1:4, which can ensure product safety. The research has significant value and significance for the governance of the remaining coal pillars and production safety.

Heavy metal contamination assessment and probabilistic health risks in soil and maize near coal mines.

ObjectiveCoal mining activities have continuously introduced heavy metals into the soil–crop system, causing increasing damage to crops. This study integrated the analysis of the heavy metal contamination status and human health risk in soil and maize near coal mines to help formulate control strategies for soil quality, maize production, and safe consumption.MethodThis study was carried out on maize agricultural land near a coal mining plant. Heavy metal contamination was assessed by the geo-accumulation index (Igeo), enrichment factor (EF), and bioaccumulation factor (BCF). The Monte Carlo simulation was used to estimate the probabilistic health risk of heavy metals exposure in soil and maize. The relationship between the concentration of heavy metal in the soil and that in maize was further visualized by correlation analysis and random forest analysis.ResultsThe results revealed that the mean concentrations of soil Ni, Cu, As, Cd, Sn, Zn, Pb, and Hg were all above the local background level. Ni was the most severely polluted heavy metal in maize and had a concentration higher than the risk control standard for corn in China (NY 861-2004). The Igeo values of all heavy metals were low, and EF values showed enrichment in V, Cr, Ti, Ni, and As. The assessment of probabilistic health risk exposed by heavy metals in soil and maize indicated that 1.16 and 1.46% of residents exceeded the carcinogenic risk level due to heavy metal exposure from soil and maize, respectively. Children were the most sensitive to maize and soil heavy metal exposure in the contaminated area. Ingestion of heavy metals was associated with the highest health risk to residents, followed by dermal contact and inhalation. As and Cr in soil and Cr and Ni in maize had the greatest impact on human health risk. Furthermore, maize heavy metals were affected the most by soil Cr, Cd, and V.ConclusionThese results may provide useful information for human carcinogenic risk associated with soil and maize heavy metal exposure due to coal mining activities.

The dynamics of soil carbon in revegetated post-coal mining sites: A case study in Berau, East Kalimantan, Indonesia

Abstract. Hartati W, Sudarmadji T. 2022. The dynamics of soil carbon in revegetated post-coal mining sites: A case study in Berau, East Kalimantan, Indonesia. Biodiversitas 23: xxxx. Open pit mining practices cause the loss of vegetation cover as well as soil degradation. Post-mining land reclamation and revegetation are therefore enforced to recover the vegetation and soil quality. While several studies have revealed vegetation succession following post-mining revegetation, limited studies have focused on the carbon dynamics of the soil. This study aimed to investigate the dynamics of soil carbon stock due to mining operations and how it changed following revegetation. The research was carried out in the concession area of a coal mining company in Berau, East Kalimantan, which was divided into three sites: Sambarata Mining Operation (SMO) Site, Binungan Mining Operation (BMO) Site, and Lati Mining Operation (LMO) Site. At each site, eight research measurement plots (RMP) were established representing land with varying vegetational conditions, namely original land and post-mined lands with varying revegetation stages from open land to 12-year-old vegetation. The percentage of C content was calculated from 288 disturbed soil samples, while bulk density was analyzed from 144 whole soil samples using the Walkey & Black and gravimetric methods. We found that the C stock at the initial state after the mining operation was very low. Coal mining activities caused a loss of C in soil with an average value of 21.29%, or equal to 5.65 tons/ha. The biggest loss occurred at the SMO site (44.97%, or 13.04 tons/ha), while the smallest loss was found at the LMO site (2.24%, or 0.40 tons/ha). The carbon stock improved after revegetation, particularly in the SMO and LMO sites, and the rate of carbon stock enhancement in the soil differed across sites. The results also showed that soil carbon in the post-mining area of 10-30 cm was greater than that of the 0-10 cm layer. Along with the increasing age of plants, the vertical distribution of C stock shifted from the lower layer to the upper layer.

Preparation and Characterization of Ceramic Membrane Composition Variations in Pome Waste Treatment

Palm Oil Mill Effluent (POME) is waste generated by the palm oil industry consisting of solid, liquid and gaseous wastes. POME is decomposed in sewage ponds and allowed to decompose naturally. The residual waste generated by this industry is non-toxic but has high polluting power. To overcome this, it is necessary to treat waste by making ceramic membranes. The composition materials needed are clay, zeolite, sodium carbonate and boric acid. The manufacturing method is through the printing and combustion stages at a temperature of 900oC. The results showed that there was an effect of compositional variations on the quality of the final product, namely TSS rejection % 93.355 with a flux value of 0.2474 (L/m2min). From the parameter values obtained, it proves that the ceramic membrane is able to process POME with satisfactory effective results. The quality standard of palm oil liquid waste is in accordance with South Sumatera governor regulation number 8 of 2012 concerning quality standard of liquid waste for industrial, hotel, hospital, domestic and coal mining activities

Soil Loss Analysis of an Eastern Kentucky Watershed Utilizing the Universal Soil Loss Equation

Soil erosion is the displacement of soil’s upper layer(s) triggered by a variation in topography, land use and soil types, and anthropogenic activities. This study selected the Marrowbone Creek-Russel Fork watershed in eastern Kentucky to estimate the mean annual soil loss over eight years (from 2013 to 2020) utilizing the Universal Soil Loss Equation (USLE). We included monthly precipitation, soil survey, digital elevation model (DEM), and land cover data to estimate the parameters of the USLE. The mean annual soil loss for the study area ranged from 1.77 to 2.91 Mg ha−1 yr−1 with an eight-year mean of 2.31 Mg ha−1 yr−1. In addition, we observed that developed land cover classes were less erosion-resistant than undeveloped land cover classes over the observation period. The results of this case study in our small watershed that has been historically impacted by upstream coal-mining activities are comparable to the results from similar studies in other geographic regions. However, we suggest other researchers conduct similar studies using robust data to determine the applicability of the USLE model and validate the results in developing measures to address soil loss issues.

Identification of the disturbed range of coal mining activities: A new land surface phenology perspective

• We propose a new index based on phenological responses to effectively identify the disturbance ranges of coal mining activities. • The range of influence of PS on vegetation phenology -climate coupling relationship is 11–12 km. • Underground mining may have a greater impact on vegetation phenology than surface mining. Coal mining activities not only damage the ecosystems located inside mining areas, but also affect the buffer areas located within a certain radius of the mining activities. Effectively identifying the range disturbed by mining activities is beneficial for guiding ecological restoration and ecological assessments in mining areas. However, methods for quantitatively identifying the range of disturbances associated with coal mining activities are still lacking. In this study, the phenological disturbance range index (PDRI) based on remote sensing observed vegetation phenology was proposed. Normalized difference vegetation index (NDVI) time series data were collected, and land surface phenology parameters were estimated in the Pinshuo mining area on the Loess Plateau. The proportion of the phenology-climate coupling relationship destroyed by human activities was then calculated. The range of mining activity disturbances was then determined by mutually validating the function-fitting and trajectory-segmentation algorithms. The results show that the proposed PDRI can effectively identify the extent of disturbances resulting from mining activities. Clear differences among the PDRIs reflecting mining activity disturbances, urbanization disturbances and natural states were found. Taking the Pingshuo mine as an example, the range of disturbances was approximately 11 ∼ 12 km, and shaft mining was found to have a greater impact than open pit mining. The PDRI proposed herein solves the initial problem from a climate-response perspective and can be used as a standardized scheme to detect the extent of disturbances resulting from coal mining activities. This study can also provide a reference for policy formulation and ecological compensation range.

Associations Between Surface Mining Airsheds and Birth Outcomes in Central Appalachia at Multiple Spatial Scales.

A considerable body of research exists outlining ecological impacts of surface coal mining, but less work has explicitly focused on human health, and few studies have examined potential links between health and surface coal mining at fine spatial scales. In particular, relationships between individual birth outcomes and exposure to air contaminants from coal mining activities has received little attention. Central Appalachia (portions of Virginia, West Virginia, Kentucky, and Tennessee, USA), our study area, has a history of resource extraction, and epidemiologic research notes that the region experiences a greater level of adverse health outcomes compared to the rest of the country that are not fully explained by socioeconomic and behavioral factors. The purpose of this study is to examine associations between surface mining and birth outcomes at four spatial scales: individual, Census tract, county, and across county‐sized grid cells. Notably, this study is among the first to examine these associations at the individual scale, providing a more direct measure of exposure and outcome. Airsheds were constructed for surface mines using an atmospheric trajectory model. We then implemented linear (birthweight) and logistic (preterm birth [PTB]) regression models to examine associations between airsheds and birth outcomes, which were geocoded to home address for individual analyses and then aggregated for areal unit analyses, while controlling for a number of demographic variables. This study found that surface mining airsheds are significantly associated with PTB and decreased birthweight at all four spatial scales, suggesting that surface coal mining activities impact birth outcomes via airborne contaminants.

Disposal slope design based on low-plasticity rock’s shear strength in coal mining activities

<p>Slope stability is the primary factor in designing a stable slope. The strength of the disposal slope relies on the characteristic of the dump materials. The rock shear strength denotes rock ability to withstand the burden, both constant and dynamic load. The weakest material used as a reference in designing the disposal slope is siltstone in Pulaubalang formation (location-04). The safety value in Location 04 and 02 tend to drop quickly as the inclination increase, while the safety in location 01 and 03 tend to fall slowly. This indicates that rocks with a lower plasticity index tend to be stronger in steeper slope conditions. The slope geometry was designed to be 10, 15, 20, and 25 meters high with a slope angle of 10<sup>o</sup>, 15<sup>o</sup>, 20<sup>o</sup>, 25<sup>o</sup>, 30<sup>o</sup>, 35<sup>o</sup>, 40<sup>o</sup>, 45<sup>o</sup>, 50<sup>o</sup>, 55<sup>o</sup>, and 60<sup>o</sup>. The slope geometry is considered stable and safe. However, this study suggests that the most effective slope design is the slope with 25 meters high, overall slope of 25,3<sup>o</sup>; the single slope of 35<sup>o</sup>; berm width 4,66 meters, bench height of 5 meters, with the safety factor value of 4.30 (SF= 4.30).</p>