GPR based RTM imaging technology for estimating rhizome diameters and application in the western China mining area

The rhizome functions are of great significance to the ecological protection of the western China mining area,whose ecological management can be provided with technical support via accurate calculations of the rhizome biomass.The rhizome diameter is an important index parameter of rhizome biomass.In this study,we propose an estimation of rhizome diameters based on ground penetrating radar(GPR)-based reverse time migration(RTM)imaging technology.First,the spatial distribution of shallow rhizomes is simulated using the finite difference time domain method.The simulation data are examined via RTM imaging and single-channel rhizome analysis to obtain the rhizome index parameters:Δh,the width of the maximum positive peak amplitude measured at an amplitude of zero,andΔH,the distance between the zero-amplitude position above the largest positive peak in the shallow region and the zero-amplitude position below the largest positive peak in the deeper region.The experiments of physical models verify the effectiveness of the two parameters(Δh andΔH).and indicate that the values ofΔh andΔH are independent of the rhizome burial depth;instead,they are only related to the diameter of the rhizome.For both the numerical simulations and the physical model experiment,the estimation errors ofΔh andΔH for the rhizome diameters can be constrained to less than 6%and 5%,respectively,which shows that the estimation of the rhizome diameters using GPR based RTM imaging technology is reasonable and effective and its high estimation accuracy meets the technical requirements.

A New Discovery on the Deformation Behavior of Shale Gas Reservoirs Affecting Pore Morphology in the Juhugeng Coal Mining Area of Qinghai Province, Northwest China

Objective The Juhugeng mining area in Qinghai Province of northwest China has attracted wide attention among geologists for it hosts typical coal measure gases.The shale gas reservoirs were reformed by intensive structural movements during geological periods,

A review on investigation of water-preserved coal mining in western China

Yushenfu mining area is located in an ecological fragile area in western China, the coal seam of which is the Jurassic Ysn'an Foirnalion. The Jurassic Yan'an Formation con tains five minable coal seams, the top layer of which is thick, covered by shallow overburden and located under aquifers. Therefore, the mining induced water flowing fractured zone can easily extend to the aquifers of both the Quaternary Sarahu and Jurassic Zhiluo Formation. This would result in a series of negative hydrological and ecological effects, including groundwater leakage, groundwater lowering, furtherly causing surface vegetation withering and dying, surface water body reduction, spring drying out, and water flow of river being decreased substantially. To solve these environmental problems, several technologies have been carried out by Chinese scientists, one of which is water-preserved coal mining. This paper presents a review of the origin, definition and development of water-preserved coal mining, and its applications in Yushenfu mining area. The applicable conditions, research contents, research methodology, and technical foundation of water-preserved coal mining are addressed in this paper. The future research focuses regarding water-preserved coal mining in China are also discussed in this paper. Its results serve as a guide for selecting the methods to be preferred for mining in case the geological conditions, roof overburden structure and coal mining process are similar to Yushenfu mining area.

Monte-Carlo Method for Coalbed Methane Resource Assessment in Key Coal Mining Areas of China

Monte-Carlo method is used for estimating coalbed methane （CBM） resources in key coal mining areas of China. Monte-Carlo method is shown to be superior to the traditional volumetric method with constant parameters in the calculation of CBM resources. The focus of the article is to introduce the main algorithm and the realization of functions estimated by Monte-Carlo method, including selection of parameters, determination of distribution function, generation of pseudo-random numbers, and evaluation of the parameters corresponding to pseudo-random numbers. A specified software on the basis of Monte-Carlo method is developed using Visual C＋＋ for the assessment of the CBM resources. A case study shows that calculation results using Monte-Carlo method have smaller error range in comparison with those using volumetric method.

Prevention and Control Mode of Desertification in China＇s State Energy Group Shendong Mining Area with Annual Coal Output of 200 Million Tons

According to the strategic goal of sustainable development,construction and management for the construction of Shendong mining area with ecological safety,the ecological restoration principle of ＂ control protects development and development promotes control＂ for desertification prevention and control was adopted,and engineering measures,plant greening measures,and enclosure management and protection measures were taken to prevent and control desertification in the mining area based on careful detailed investigation and accurate planning and design in the early period. After 32 years,the desertification ecological landscape environment of the mining area has undergone a qualitative change,and the vegetation coverage has increased from 3%-8% to above 60% after the development. The former desertification land has become a modern green energy base that has produced 200 million tons of coal every year. The construction and management mode of an ecologically safe and modernized green coal mining area built by Shendong in the desertification region of northwestern China shows that taking appropriate comprehensive ecological restoration construction technology and management measures that integrate engineering,plants and enclosure management and protection is an effective technical and management paradigm for the construction of a modernized green large-scale coal mining area in China＇s arid and semi-arid regions.

Soil Heavy Metal Pollution and Health Risk Assessment of Abandoned Land in Coal Mining Areas in Xingren County

Total contents of heavy metals （ Pb, Cr, Cd, Hg, As, Cu, Zn, and Ni） in 68 soil samples were determined to evaluate the contamination level of soil from five coal mine areas in Xingren County, Guizhou province. The pollution levels of heavy metals were characterized by anthro- pogenic influence multiple, and the pollution of heavy metal in soil was evaluated using geo-accumulation index. Based on the health risk models recommended by the U.S. Environmental Protection Agency （ US EPA）, the health risks of heavy metals in the soils were assessed. The results showed that the abandoned land in the five coal mining areas were contaminated by heavy metals, and the order of pollution levels of eight heavy metals was As 〉 Pb 〉 Cu 〉 Hg 〉 Ni 〉 Cr 〉 Cd 〉 Zn. The soils suffered moderate-heavy pollution from As and Pb, and the contents of As and Pb in the soils were 13.16 and 4.76 times higher than the background values of Guizhou Province, followed by Cu, Hg and Ni , while soil pollution from Cr, Cd and Zn was mild. The order of non-caminogenic risks of the heavy metals in the soils was As 〉 Pb 〉 Cr 〉 Ni 〉 Cu 〉 Hg 〉 Cd 〉 Zn, and the non-carcinogenic dsk value of As was higher than that its threshold value 1, which indicated that As had a high potential health risk to adults and children. The order of carcinogen risks of the four heavy metals was As 〉 Cd 〉 Cr 〉 Ni, and the carcinogenic risk value of As was higher than its threshold value, indicating that As had a high carcinogenic risk to adults and children. The carcinogenic risk values of other three heavy metals （ Cd, Cr and Ni） were lower than the threshold value, so they had no carcinogenic risk to human health. Moreover, children were more sensitively affect- ed by heavy metals from the abandoned land. Therefore, the health of children in such areas should be paid more attention to. The HI value of the eight heavy metals to children was seven times higher than that to adults. The contribution rate of HQAs to HI was about 88%, and the contribution rate of CRA, to TCR was about 98%, so As was the most crucial factor influencing non-carcinogenic and carcinogenic dsk in the abandoned soils.

Effects of Coal Mining Subsided Water Area on Temperature Change in Huaibei Coal Mine

[Objective] The study aimed to discuss the effects of coal mining subsided water area on temperature change in Huaibei coal mine. [Method] Based on the data of monthly temperature from 1957 to 2007 recorded by Suixi （coal mining subsided water area） and Fuyang stations （control）, the effects of coal mining subsided water area on temperature change in Huaibei coal mine were discussed using linear trend estimation and comparative analysis methods. [Result] Spring, autumn, winter and annual average temperatures of coal mining subsided water area （Suixi） were increased in the last 51 years, and the increase of winter temperature was mostly significant with a tendency rate of 0.49 ℃/10 a. Meanwhile, annual temperature range of coal mining subsided water area was decreased from 1957 to 2007. Temperatures of Suixi in four seasons were lower than those of Fuyang from the 1960s to 1990s, and temperatures of coal mining subsided water area （Suixi） were higher than those of Fuyang in spring, autumn and winter but lower than those of Fuyang in summer from 2000 to 2007. [ Result] Coal mining subsided water area had certain effects on temperature change of Huaibei coal mine.

Technology Development and Engineering Practice for Protection and Utilization of Water Resources in Coal Mining in Western China

Shanxi,Shaanxi,Inner Mongolia,Ningxia,and Gansu(hereafter generally referred as "the Western Area")are major coal-producing areas in China due to rich coal resources and good mining conditions.However,the Western Area has a serious water shortage.The surface evaporation is huge and a great amount of mine water generated in coal mining is evaporated and lost after discharging to surface.In order to protect and utilize the water resources during large-scale coal mining in the Western Area,Shenhua Group has put forward a technological idea to store mine water in underground mined areas and successfully researched and developed the coal mine underground reservoir technology by solving the technical difficulties of water source prediction,reservoir site selection,reservoir capacity design,dam construction,safety guarantee,water quality control and so on through20 years of exploration.Now Shenhua Group has successfully established a batch of reservoir in the Shendong Mining Area,obtaining great economic and social benefits.The technology is also extended to other western mining areas,providing an effective path for harmonic mining of coal and water resources in western China.

矿区践行生态文明建设高质量发展总体设计及案例

科教融合、产教融合立体化平台已成为推动生态文明建设和高质量发展的重要途径,各地政府出台了一系列支持政策,鼓励企业与高校合作,加强人才培养和科技创新。本文采用文献资料法、案例分析法和比较研究法等,在对国内外科教融合、产教融合实践进行梳理和分析的基础上,以中煤平朔矿区黄土高原矿区土地复垦野外科学观测研究站为基础构建的数据观测-规律发现-技术转让-政策制定一体化产学研协同平台为案例,分析了科教融合、产教融合发展的历程和成效,系统设计了基地在科学研究、教育教学、科学普及和文化建设等功能方面提升的内容和路径,旨在为我国同类企业提质增效、高校复合型人才培养及资源型城市绿色转型提供本土化可借鉴模式。

西部煤矿区微生物修复促进植物水分高效利用策略

西部煤矿区生态环境脆弱,叠加高强度开采致使水土流失、土壤退化、根系受损,植物水分利用效率低,生态恢复困难,提高水分利用效率成为西部矿区生态修复或重建的关键。土壤水是限制干旱半干旱煤矿区生态修复的关键因素,它连接大气水、地表水、地下水与植被生长,是水分循环与养分运输的重要载体。土壤水分的高效与合理利用关系到生态修复的成败,因此探究植物根系水分利用策略对于西部煤矿区生态修复具有重要作用。分析了国内外植物水分利用的主要研究方法,比较了不同方法之间的优缺点及相应研究进展。在干旱半干旱煤矿区受损生态环境中,采用植物-微生物联合的微生物修复技术,能提高植物水分利用效率,改善植物水分利用策略。同时,接种微生物降低了植物从浅层土壤吸收水分的比例,有效地增加植物从深层土壤中吸收和利用水分,提升了植物水分利用效率,使接菌植物在干旱半干旱煤矿区表现出更高的生态适应性。分析了目前西部煤矿区植物水分利用的研究进展和存在的问题,探讨了煤矿区微生物修复对水分利用策略的改善,提出了西部干旱煤矿区生态修复中不同植物组合对水分利用策略的影响及其研究重点,为实现矿区绿色可持续、高质量发展奠定了扎实的基础,具有重要的生态应用价值。

我国煤矿区生态环境现状及综合整治对策

本文总结了我国煤矿开发对生态环境破坏的总体状况，指出了我国煤矿区生态环境的特征，即华北地区和华东部分地区煤矿开发高强度与煤矿区人多地少的矛盾，西部地区煤炭储量丰富区与生态环境脆弱性的矛盾和我国广大南方煤矿开发分散与煤质差、污染重的矛盾。从生态环境规划、法制管理、整治措施、应用基础研究等方面对我国当前煤矿区生态环境整治工作中存在的问题进行了全面的分析，并提出了适应我国国情的煤矿区生态环境综合整治对策。

华北地区构造应力场非均匀特征与煤田深部应力状态

将华北地区分成11个应力小区,依据华北地区近期1111条中小地震震源机制解数据,利用格点尝试法分析华北地区主应力方向的分布特征,结果显示,华北地区现今构造应力场以水平作用为主,其中,唐山和晋南地区最大主应力方向为近EW向,其他地区最大主应力方向均为NEE向,方位为NE60°～80°。鲁西南万福煤矿深部水压致裂原地应力测试结果显示,水平最大主应力方向的为NE40°～80°,与鲁西南地区中小地震震源机制解的分析结果十分接近。通过构造类比,认为万福煤矿深部应力状态受控于鲁西南地区区域构造应力场。

西部重点煤矿区土地退化的影响因素及其评估

中国西部生态环境极其脆弱,煤炭资源开发与自然因素共同作用导致的矿区土地退化不容忽视,本文旨在揭示我国西部煤矿区土地退化的成因、程度、分布与趋势,为矿区土地退化防治与国土空间生态修复提供数据基础与决策依据。提出了煤矿区土地退化的概念,将煤矿区土地退化的直接因素划分为挖损、塌陷和压占,间接因素或外在表现划分为土壤侵蚀、植被退化与沙漠化或石漠化,结合实地调查并辅以高分辨率与高光谱遥感数据解译,提取了上述土地退化因素信息,并提出了土地退化外在表现的分级评价标准,进而构建了西部煤矿区土地退化的综合评价模型,对分布于黄土高原区、西南山地丘陵区、北方草原区和西北干旱区的12个重点煤矿区进行了土地退化信息提取、土地退化因素分析与土地退化综合评价。结果表明:①影响井工煤矿的万吨塌陷率的因素有累计采厚、平均采深、煤层倾角及上覆岩性,影响露天煤矿的万吨损毁率的因素包括煤层厚度、剥离岩土厚度及其堆放方式。②不同地域的矿区土地退化主要表现有所不同:黄土高原区为植被退化和土壤侵蚀,西南山地丘陵区为土壤侵蚀,北方草原区与西北干旱区植被退化、土壤侵蚀与沙漠化3者兼有。③矿山尺度的土地退化要比矿区尺度的更为剧烈,露天开采引起的土地退化要强于井工开采;矿区尺度的土地退化程度与煤炭资源开发强度(用煤矿扰动面积与矿区总面积之比表示)有关,开发强度越大,矿区土地退化程度越严重,而土地退化程度与开发强度并不呈正比,它还与矿区的生态脆弱性或承载力有关。因此,不同区域、不同采煤方法造成的土地退化形式及退化程度不一,因此需要采取不同的修复策略;为防止过度土地退化,需要根据矿区生态承载力确定合适的开发强度。

西部生态脆弱区煤炭减损开采地质保障科学问题及技术展望

我国能源禀赋特点决定了煤炭主体能源地位短期难以改变,其中,西部煤炭资源担负着我国基础能源自主供给的核心角色。但西部煤炭多处于干旱-半干旱带沙漠-黄土覆盖生态脆弱区,易因开采扰动引起地下水及生态环境产生显著影响。因此,减损开采成为西部生态脆弱区煤炭资源安全高效开发与环境保护协调发展的必然选择。立足西部煤炭资源开发现实情况,提出了西部生态脆弱区煤炭减损开采面临的四大关键科学问题,即:①煤-水空间发育组合特征;②采动过程地质条件变化规律;③保水开采分区及地质判据;④西部煤炭减损开采技术体系构建思路。同时,详细阐述了煤炭减损开采技术发展状况及存在的现实难题。在此基础上,尝试构建西部生态脆弱区煤炭减损开采技术体系,并展望了西部煤炭减损开采技术未来发展方向。相关研究以期为西部生态脆弱区煤炭绿色减损开采提供借鉴。

西部典型煤矿区水体污染遥感监测应用

利用Sentienl-2A(哨兵2号)和ZY-3(资源三号)卫星数据,通过高空间分辨率目视解译与短波红外(SWIR)经验模型相结合的方法,对神东和准格尔2个西部典型煤矿区内煤尘水体污染开展提取分类和统计分析。结果表明,无论是在井工开采为代表的神东矿区还是露天开采为代表的准格尔矿区,煤矿开采活动造成的地表水体污染均十分严重,其中神东矿区污染水体面积占总地表水体的比例约为86. 44%,准格尔矿区污染水体面积占总地表水体的比例约为74. 82%;造成水体污染的主要因素为煤尘颗粒和洗煤废水,矿区内部水体、周边水系、黄河干流呈现轻度至重度污染,临近矿区、流动性差、循环慢的水体污染情况更严重。该方法优于传统目视解译,其人为干预少,理论依据明确,可快速开展定性评价,能在宏观层面为矿区管理者提供指导,可用于煤矿区开展长期动态监测。

西部干旱半干旱露天煤矿生态重构技术难点及发展方向

露天煤矿开采对生态环境最严重和直接的影响是对水资源破坏与土地资源的挖损占压,以及对生态系统的物种破坏。西部干旱半干旱露天矿区生态重构的关键是水资源保护与利用、排土场土层结构重构、表土改良和植被优化组合。西部干旱半干旱露天矿区生态重构核心技术是研发露天矿区岩层结构与含水量探测技术,监测地下水存在的范围与边界。以水资源量为约束,构建排土场近地表合理的土层结构,实现重构土层保水涵水动态协调供给。提出干旱半干旱露天矿排土场近地表高效低成本的表土生态层-涵水层-隔水层的3层土层重构结构模型,研发物探检测成套技术与装备,监测矿坑水来源、排土场土层结构与含水率,保证生态工程水资源有效利用。结合土地的生态承载力,对排土场重构生态进行功能分区与景观设计。开发新型微生物菌剂培养配方,揭示微生物改良土壤及抗逆境机理,形成较好的有机生物立体生态重构模式,可产生较好的经济、生态和社会效益,促进矿区绿色可持续发展。通过对西部干旱半干旱露天矿区及其周边环境动态观测,在生态条件差的地区,人工干预能有效地打破原始生态禁锢,刺激生态正向发展,获得西部干旱半干旱露天矿区自然与人工生态协调发育规律。解豁了科技界担心大规模的煤炭开发使西部干旱半干旱地区的生态环境进一步恶化,造成“雪上加霜”效应的难题。同时针对西部干旱半干旱区露天矿排土场重构土壤的结构差、肥力低、植物种类单一,重构生态难的现状,采用微生物-植物联合修复技术,研发多型号生物修复菌剂和基质,有效地促进了植物根系发育,增强了植物抗土壤压实、养分贫瘠、干旱缺水及易盐碱化等逆境的生理生化反应,人工干预重构后的生态环境比原生态效应提高10倍以上。实践了西部露天煤矿区开发金山银山,再造绿水青山的生态理念。

西北干旱荒漠区煤炭基地生态安全保障技术

"西北干旱荒漠区煤炭基地生态安全保障技术"项目(2017YFC0504400)是国家重点研发计划项目,贯彻包括《中共中央国务院关于加快推进生态文明建设的意见》(2015)、《全国造林绿化规划纲要(2011—2020年)》以及国家"十三五规划"—煤炭清洁高效工程等关于矿区生态修复的各项国家相关政策,加强项目实施与创新发展战略、"一带一路"战略的密切结合。项目从基础理论研究、关键技术研发、工程示范等多个层面出发,明确西北干旱荒漠区煤炭基地生态退化机制,研发水土资源保护与高效利用、沙尘防控、植被恢复关键技术,并进行煤炭基地生态恢复工程示范,旨在为西北干旱荒漠区煤炭基地生态恢复与生态保障提供技术支撑。

富水弱胶结顶板巷道支护优化设计研究

为了解决西部煤矿富水弱胶结顶板巷道支护优化设计的问题,通过对西部煤矿富水弱胶结顶板取芯岩石试件试验研究,得出其岩石试件在浸水24h后即达到浸水饱和状态,在垂向上易发生膨胀变形离层,且单轴抗压强度较常态下降低了18.9%。根据试验结果及现场实际地质情况,提出了断面优化、顶板支护锚固力增强优化技术、巷道的梯度锚固优化技术这三种针对性的巷道支护优化设计。现场观测结果表明:在经过巷道支护优化后,巷道掘进期间顶板浅深部离层绝大多数都在0~10mm内分布,巷道围岩锚杆(索)增幅载荷大部分在11~30kN分布,均在锚杆及锚索的承载能力范围内,巷道掘巷期间矿压显现不明显。实现了巷道掘进安全支护,同时为西部煤矿富水弱胶结顶板巷道支护进行了优化支护实践论证。

煤矿地下水库理论框架和技术体系

针对我国西部(晋陕蒙宁甘)地区富煤缺水,且蒸发量是降雨量的6倍左右的条件,以及西部煤炭规模化开采产生的裂隙场,破坏了原有的地下水系统,产生大量矿井水,为保障煤矿安全,解决将大量矿井水外排地表蒸发损失的问题,提出了"导储用"为核心的煤矿地下水库地下水保护利用理念,研究开发了涵盖煤矿地下水库设计、建设和运行的技术体系,包括水源预测、水库选址、库容设计、坝体构建、安全运行和水质保障等六大关键技术,并在神东矿区成功建设了示范工程,累计建成32座煤矿地下水库,为矿区提供了95%以上用水,且实现了长期低成本安全稳定运行。工程实践表明,煤矿地下水库是充分利用地下自然空间和自然力储存和净化矿井水的安全、低成本、规模化的储水技术,为西部地区煤炭开采地下水资源保护利用提供了有效技术支撑。

西部矿区沿空掘巷无冲击窄煤柱研究

为解决西部矿区采深增加带来的20~40 m区段煤柱防冲控制难等问题,提出了临界煤柱尺寸的设计方向,以彬长矿区高家堡煤矿为例开展了沿空掘巷无冲击窄煤柱的设计原则研究。通过有限元数值模拟分析了巷道开掘前后的应力分布环境,确定了无冲击窄煤柱的尺寸范围。针对5、6、7、8 m四个不同煤柱宽度参数,开展了基于围岩应力状态、围岩变形和安全性能的的综合对比分析,结合工程类比、理论分析,最终确定了合理的煤柱参数取值范围。选取8 m煤柱,开展了巷道开掘后的围岩应力二次分布规律研究,确定了围岩表面位移的临界参数,并在受冲击威胁的综放工作面回风巷内进行了8 m煤柱的工业试验,试验结果验证了设计的合理性。