Ecological effects analysis of land use change in coal mining area based on ecosystem service valuing: a case study in Jiawang

Land use change is one of the uppermost driving forces of regional ecosystem change, and has a huge impact on the environmental balance. Mining areas with intensive resources exploitation and utilization have undergone different kinds of environmental influences, such as water pollution and land use cover change. The extensive coal mining in China has led to significant regional land use change resulting in major ecological damage. The objective of this study was to form a clearer picture of the regional ecological environmental situation for promoting ecological protection and improvement by ecosystem service valuing. The case study area was selected at Jiawang town, which has undergone extensive coal mine exploitation for many decades. The study investigated the relationship between land use change and ecological environment, and described the ecosystem service value variations in Jiawang, based on remote sensing and GIS technology. After modification of regional ecosystem service value coefficients, the method was used to evaluate the conditions in the study area from 1990 to 2005 based on the land use/cover information interpreted from TM/ETM+ images. The characters and changes of ecosystem service values were then analyzed both quantitatively and spatially.     

基于遥感技术的宁东煤炭基地土地利用变化及驱动力分析

研究大型矿业基地土地利用动态变化过程可间接评估矿产开发对区域生态环境的影响。采用2005年、2010年和2015年3期SPOT-5和GF-2卫星影像数据,通过人工目视解译与计算机自动提取相结合的手段,提取宁东煤炭基地土地利用信息,并收集2000年土地利用遥感解译信息,构建土地利用程度综合指数、动态度等,定量研究宁东煤炭开发引起的土地利用变化,结合经济社会发展指标,构建驱动土地利用变化的定量评价体系,分析了宁东煤炭基地土地利用格局变化的驱动因素。结果表明,2000—2015年宁东煤炭基地一直处于土地持续开发利用阶段,主要表现为草地、林地及耕地向工矿用地为主的建设用地转变,但土地利用程度综合指数的增幅有所下降,表明基地建设逐渐进入稳定期,土地利用压力趋于下降;主成分分析表明,人类活动驱动着宁东土地利用格局的变化,主要有封山禁牧政策、产业化和规模化、人口增长、城镇化等因素。该研究结果可为宁东煤炭基地未来生态环境保护提供科学依据。     

Mapping and detection of land use change in a coal mining area using object-based image analysis

Object-based image analysis was used to map land use in the Panxie coal mining area, East China, where long-term underground coal mines have been exploited since the 1980s. A rule-based classification approach was developed for a Pleiades image to identify the desired land use classes, and the same rule-based classification strategies, after the threshold values had been modified slightly, were applied to the Landsat series images. Five land use classes were successfully captured with overall accuracies of between 80 and 94%. The classification approach was validated for its flexibility and robustness. Multitemporal classification results indicated that land use changed considerably in the Panxie coal mining area from 1989 to 2013. The urban, coal and coal gangue, and water areas increased rapidly in line with the growth in mine production. Urban areas increased from 9.38 to 20.92% and showed a tendency to increase around the coal mines. From 1989 to 2013 the coal and coal gangue area increased by 40-fold, from 0.02 to 0.58%. Similarly, the water area increased from 2.77 to 7.84% over this time period, mainly attributable to the spread of waterlogged areas. The waterlogged areas increased to about 2900 ha in 2013, which was about 80 times more than their area in 1989. In contrast, the area of cultivated land was negatively related to the increase in mine production and decreased from 73.11 to 57.25%. The results of this study provide a valuable basis for sustainable land management and environmental planning in the Panxie coal mining area.     

GPS/terrestrial 3D laser scanner combined monitoring technology for coal mining subsidence: a case study of a coal mining area in Hebei, China

In order to overcome the shortage that point-based data acquisition techniques cannot retrieve the whole basin subsidence caused by underground mining, and to avoid complex splicing of terrestrial 3D laser scanner (TLS) point cloud data and the errors caused by such splicing, GPS/TLS combined technology is employed for mining subsidence monitoring. The basic idea of the monitoring technology is put forward. In this article, an application of the method to a coal mining area in China is presented. Support vector machine (SVM) model for GPS level conversion in the mining area is established, and a comparative analysis of SVM, BP neural network and polynomial established local quasi-geoid in the mining area is conducted. Ground surface digital elevation model (DEM) of the mining area is established by using TLS point cloud data, and the ground surface dynamic subsidence basin is obtained through a subtraction of two DEMs. The results indicate that the quasi-geoid established by using SVM model features a relatively high level of stability and accuracy and that the established mining surface DEM and subsidence basin can provide the fundamental data for the reconstruction of ecological environment in the mining area. GPS/TLS combined monitoring technology is a new monitoring technology, which entangles the advantages of both GPS and TLS and could offset their disadvantages, thus obtaining complementary advantages. According to analysis on its application in the mining area, we conclude that the technology is feasible and has a great application prospect for the mining area purposes.     

基于GIS的岩溶煤矿区土地利用适宜性评价研究——以重庆市南桐矿区为例

以SPOT5卫星为基本信息获取该地区的地貌数据,并根据该地区的土地利用现状、土壤特征、煤炭开采状况等9个指标,采用多因素分级指标综合评价法对南桐矿区的土地利用适宜性进行评价。按照土地的用途划分宜耕、宜园和宜林土地类三个类型,根据影响因子对土地用途的影响程度制定分级指标。评价结果表明,高度适宜、中等适宜、基本适宜和不适宜耕地分别为5 321hm2、8361hm2、7 973hm2和4 656hm2;园地分别为315hm2、629hm2、405hm2 和117hm2;林地分别为8 867hm2、7303hm2、5 977hm2 和2 643hm2。为能更好地利用土地资源和促进矿区的可持续发展,建议将原来的耕地、园地和林业用地比例10∶ 0. 6∶ 9. 4调整为10∶ 5. 7∶ 14。      

煤炭开发区植被扰动时空效应及影响范围界定:以宁东矿区为例

煤炭开采是一种具有大规模高强度性质的生态扰动行为,会产生区域地表压占与损毁、植被破坏等生态扰动和环境污染问题.西北干旱荒漠区气候干旱,植被稀疏,生态环境本身极其脆弱,宁东矿区是典型的干旱荒漠煤炭开发区,有重要的研究价值.本文选择宁东矿区以及与矿区自然条件相近的自然植被参照区作为研究对象,收集2008—2019年共276...     

Influence of coal mining on regional karst groundwater system: a case study in West Mountain area of Taiyuan City,northern China

Karstic limestone formations in the West Mountain area are important water resources for Taiyuan City in Shanxi Province, northern China, which is also known for its large-scale coal mining production. In this study area, groundwater is not only exploited for water supply purposes but also drained because of coal mining. The process of coal mining changes both the quantity of the karst springs and the quality of karst groundwater system because of overexploitation and overdrainage. In this paper, the influence of coal mining on the groundwater is analyzed from a qualitative and quantitative perspective. The hydrochemical analysis results reflect the relationship of the recharge, runoff, and drainage; the features of the medium; and water-rock interactions. Based on a qualitative understanding of the geological deposition and characteristics of the groundwater flow system, three-dimensional groundwater flow models are established and applied to several scenarios to explore the quantitative influence and allow better protection of the groundwater environment and better utilization of water resources.     

煤矿塌陷区覆土造地综合研究——以新庄孜矿为例

以新庄孜矿为例,针对覆土造地过程中,煤矸石充填可能带来的重金属元素的迁移污染作了相关分析。采用煤矸石充填塌陷区,既减少矸石山占地面积,又能在塌陷区覆土造地;同时,填埋矸石有利于保护环境,防止环境污染,具有较大的经济效益、社会效益和环境效益,对淮南矿区覆土造地及工农业持续发展具有重要的示范意义。     

Effect of acid mine drainage on a karst basin: a case study on the high-As coal mining area in Guizhou province,China

Acid mine drainage (AMD) is a common pollution in mining areas due to the oxidation of pyrite and associated sulfide minerals at mines, tailings and mine dumps. Elevated metals (Fe, Mn, Al) and metalloids (As, Hg) in AMD would deteriorate the local aquatic environment and influence the water supply. A carbonate basin with deposits of high-arsenic coal in Xingren County, southwestern China, was chosen to study the behavior of As and other chemical constituents along a river receiving AMD. Heavy metals (Fe, Mn) and major ions such as (Ca²⁺, Mg²⁺, Cl⁻, SO₄ ²⁻) in surface water, and As in sediment and surface water were analyzed. It was found that high concentrations of SO₄ ²⁻ (1,324–7,560 mg/L) and Fe (369–1,472 mg/L) in surface water were mainly controlled by the interactions between water and rocks such as the oxidation of pyrite in the local coal seams, precipitation and adsorption of iron minerals. Although ubiquitous carbonate minerals in the bedrock and the riverbeds, low pH (<3) water was maintained until 2 km downstream from the AMD source due to the Fe(hydro)oxide minerals coating on the surface of carbonate minerals to restrain the neutralization of acidic water. Moreover, the formation of Fe(hydro)oxide precipitations absorbed As was dominated the attenuation of As from water to sediment. Whereas, the dilution also played an important role in decrease of As in river water.     

Characteristic analyses,simulations and predictions of land use in poor mountainous cities: a case study in the central area of Chengde County,China

Mountainous areas account for approximately 69% of the land area in China, and these areas are prone to poverty. Thus, analyzing the land use characteristics and conducting simulations and prediction studies of poor cities in mountainous areas are important research topics. The land use change processes and characteristics in Chengde County, Hebei Province, China were analyzed in this paper based on the spatial distributions and temporal changes of land use types. Fourteen driving factors and five land use types were used in performing binary logistic regression analysis. The dynamic conversion of land use and its effects model was used to simulate the land use distributions, which were further simulated under three scenarios in 2021: natural growth, ecological conservation and accelerated development. The results show that the ecological conservation scenario optimized the land use distribution and effectively protected the environment, thereby increasing the suitability of future development. Based on the research results, this paper concludes that the correct development directions in the future should include preparing accurate and effective policies, promoting industrial structure reform, driving economic transformations and improvements, and improving the land use efficiency. The experimental results provide significant technical support for preparing and revising land use plans in poor mountainous cities.     

宁东矿区瓦斯风化带内的瓦斯异常分析

在瓦斯风化带内开采煤层,瓦斯一般不会对生产构成主要威胁,但笔者在宁东矿区某矿瓦斯风化带内施工地质检查孔时却发现了高浓度的甲烷气体。通过区域地质分析和工程探测研究,发现该区域因受地质构造影响,在顶板砂岩中有游离瓦斯聚集,经过针对性钻孔抽采,3个月抽采了近200万m³的纯瓦斯。这说明在封闭条件下的瓦斯风化带内,仍可能出现瓦斯集中赋存的区域。     

基于DeepLabv3+与GF-2高分辨率影像的露天煤矿区土地利用分类

遥感与深度学习为及时掌握露天煤矿区土地利用情况提供了高效率的技术手段。基于国产高分二号(GF-2)卫星高分辨率遥感影像,利用深度学习DeepLabv3+模型实现露天煤矿区土地利用识别,并与U-Net、FCN、随机森林、支持向量机、最大似然法等方法进行对比。首先,制作高分辨率影像样本数据,通过敏感性测试确定适合研究区露天煤矿场景的样本最佳裁剪尺寸和方式;然后,训练深度神经网络DeepLabv3+模型,进行土地利用识别实验;最后,比较不同方法的识别结果。结果表明:研究区露天煤矿场景下的样本最佳裁剪尺寸为512像素×512像素,最佳裁剪方式为随机裁剪。采用的DeepLabv3+模型对露天煤矿区土地利用识别的总体精度、Kappa系数分别为80.10%、0.73,均优于U-Net、FCN、随机森林、支持向量机、最大似然法等方法的识别精度。DeepLabv3+模型的识别速度与上述5种方法保持在同一数量级,验证了DeepLabv3+模型和GF-2卫星影像在露天煤矿区土地利用识别中的可行性,对露天煤矿区生态环境监测与修复规划具有重要意义。      

Optimization of concurrent mining and reclamation plans for single coal seam: a case study in northern Anhui, China

The extraction of underground ore body inevitably causes a large amount of land subsidence. Current reclamation technologies in China mainly focus on stable subsided land, which means most of the affected lands are submerged into water because of the high groundwater table in some areas, leading to the loss of soils and inefficient reclamation. Therefore, a new technology for reclaiming unstable subsiding land is being studied for restoring farmland as much as possible, based on a case study in northern Anhui, China. In consideration of the mining plan, subsidence processes in various stages were analyzed and some related factors such as vertical subsidence, post-mining slope, water area, and land use condition were also simulated. Due to mining activities, useful farmland has gradually decreased to merely 14.4 % of the pre-mining area. In this study, the following stages were modeled from pre-mining to post-mining: (1) percentage of farmland was 100 % in stage (a) (pre-mining), (2) 72.5 % in stage (b), (3) 67.3 % in stage (c), and (4) 14.4 % in stage (d) (post-mining). The results show that 86.6 % of cultivated land was submerged into water and lost its capacity for cultivation after coal mining. Reclamation plans for stages (b), (c), and (d) were made by a traditional reclamation method called “Digging Deep to Fill Shallow”. Based on scenario simulation of reclamation, the farmland reclamation percentages were improved to 78.3, 73.3, and 40.70 %, respectively. Taking the percentage of reclaimed farmland as the preferred standard, concurrent mining and reclamation for stage (b) and (c) could increase farmland reclamation percentages to 37.6 and 32.6 %, respectively, compared with the farmland reclamation percentage of post-mining [reclaiming the land in stage (d)]. The results reveal that optimum reclamation time should be at stage (b). Therefore, under current technical conditions, concurrent mining and reclamation could enhance the quantity of cultivated land and provide better land protection and food security in the mined areas with high groundwater table.     

Explanation of land use in mountainous area,China: from field to village level

Few studies of land use change were particularly considered the hierarchical data structure originating from different scales and levels. Using interviewing data collected from 107 villages, 1,050 households and 4,780 fields between November 2003 and August 2005, the objective of this paper is to predict the occurrence of land use from field to village level in mountainous area, China, and to improve our understanding of the causes of land use. Household’s behavior in the choice of land use type is guided by multiple, often confiding, household objectives, subject to the available resources, possible productive activities, and external economic and biophysical constraints. For rice model, the household level variables cannot be substituted by village level aggregates. Aggregated variables at village level do not capture any of the variability at the household level. Village level variables can virtually be explained in virtue of the variables of field and household level. The households and the villages show significant clustering of the occurrence of rice, and they explain the 11.3 and 4.5% variance, respectively. For corn model, corn as dependent variable does not show any significant variance component. The variables of household and village level have lower effects on the occurrence of corn. There is a significant relation between slope of a field and the choice to cultivate corn and a significant random effect at the village level. However, cropland size, input–output, transportation cost, even family income in household level and road density and food market development in village level, at some extent, are controlled by slope. These variables do not influence corn cultivation significantly and that those are predominantly determined by slope. In a word, the household level can be crucial in explaining land use at the field level. Multilevel analysis can be applied to statistically model the occurrence of land use, and to explore a number of cross-scale propositions. An erratum to this article can be found at     

Responses of water quality to land use in riparian buffers: a case study of Huangpu River,China

Along with the continuous urbanization process, massive riparian buffers are developed to satisfy the increasing demands for flood protection and economic growth. Such changes of land use types and landscape patterns pose a significant challenge to the protection of the eco-system of urban rivers. This research concentrates on revealing the potential relation between the water quality of the urban river and land characteristics including land use types and landscape patterns of the riparian area and discusses if the relationship varies with spatial scales. The study area of this research are the 800 m riparian buffer of the six river water quality monitoring sections along Huangpu River. Based on the long-term monthly collection data of six monitoring points in Huangpu River, Shanghai, China, and the land use data of 100 m downstream of 1 km upstream of the monitoring point. Using landscape indicators, GIS spatial analysis, and statistical methods, the responses of land use and landscape patterns to water quality in different scales are obtained. Results show that: (1) Urban Land (UL) and Agricultural Land (AL) have an enormous negative contribution to each buffer, which is the primary non-point source pollution and influencing factor. (2) The active contribution of Wetland (WL) and Forestry Land (FL) is the most significant in the small range buffer of 0–200 m. (3) The negative effect of Industrial Land (IL) on water quality is only significant in the small buffer. (4) The effect of landscape pattern on water quality is more significant on the large spatial scale than the small scale. At the same time, this paper extends the conclusion to discuss the land use of the 800 m buffer zone of Huang River by using point to the area, proving that the research result is helpful for the political decision of urban management and provides suggestions for the land optimization of riparian buffers.

     

Analysis of mining-induced variation of the water table and potential benefits for ecological vegetation: a case study of Jinjitan coal mine in Yushenfu mining area,China

The impact of high-intensity coal mining on water resources has drastically affected the local environment in the Yushenfu mining area, Northwest China. Many studies have ascertained that coal mining has caused reduction of the phreatic water level and vegetation death, which has deteriorated the fragile arid and semiarid ecosystems. However, at Jinjitan coal mine, it has been observed that the phreatic water level rose due to coal mining, which has been beneficial for the local ecology, especially the vegetation. In this study, the variation of the phreatic water table and its ecological effects were investigated by in-situ tests and remote sensing. The results suggest that the recovery of the permeability of the loess aquitard controls the vertical leakage of phreatic water, whereas horizontal recharge is controlled by land subsidence. An ecological impact evaluation, using the normalized difference vegetation index (NDVI), demonstrates that the vegetation is being gradually improved. Compared to a small improvement of ~9.7% in the unexploited area, a?~23.3% improvement occurred in the exploited area where low-density shrubs transformed to high-density shrubs and herbs. Emergence of phreatic water at the land surface in low-lying areas of the working faces may induce the formation of an oasis and wetland system in arid and semiarid areas. These findings could change the conventional negative impression around mining and improve ecological restoration practices.

     

托木尔峰国家级自然保护区土地利用/覆被变化及驱动力分析

利用保护区的3期Landsat TM遥感影像数据,运用GIS技术并结合区域生态环境质量指数,对托木尔峰自然保护区土地利用/覆被变化及其驱动力进行分析。结果表明:近27 a来,冰川和草地面积持续增长,增幅分别为12.37%和99.36%;水体和荒地面积持续减少,减幅为23.07%和12.15%;林地前阶段(1989-2003年)减少16.77%,后阶段(2003-2016年)增加57.91%。区域土地利用/覆被综合动态度,前阶段为0.39%,后阶段为0.36%;前阶段转化率为21.95%,后阶段转化率为18.91%。水体、草地和林地的转化率较高,冰川和荒地的转化率较低;尽管土地利用/覆被类型内部结构变化较复杂、频繁,但各类型之间相互转换的活跃程度逐渐趋于平缓。研究区生态环境质量指数呈增长趋势,年均增长率为0.31%,生态环境逐年改善。致使研究区生态环境质量改善的主要驱动力为气候的变暖湿和土地利用政策的改变。近27 a来,研究区中高山带降水量的增加,扩大了保护区冰川雪地的面积;晋升为国家级自然保护区后的土地利用政策,有效遏制了人类活动对保护区土地利用/覆被的影响,进而使生态贡献率较低的荒地转化为生态贡献率高的林草地,提高了区域生态环境的质量。     

宁东煤田侏罗纪煤岩煤质特征及清洁高效利用

宁东煤田侏罗纪煤炭资源量巨大,是当前宁夏回族自治区煤炭资源开发利用的主体。为保障煤炭资源的清洁高效利用,以煤田大量勘查资料为主要依据,分析了宁东煤田侏罗纪煤的煤岩、煤质特征。结果显示：宁东煤田侏罗纪煤具有特低-低灰、特低-低硫、低磷、低砷、低氟、高发热量的特征,这些特征表明其为高清洁度动力用煤;同时还具有中高挥发分、较高氢碳原子比、焦油产率较低（普遍<7%）及富惰质组等特征表明不适于直接液化用或提取煤焦油。无黏结性、较低水分产率、较高的与二氧化碳反应性（950℃）、煤灰熔融温度,表明其适于气化,且以水煤浆气流床和干煤粉气流床为宜。综合认为研究区煤炭资源的清洁高效利用方式为动力用煤,气化用煤及以气化为基础的间接液化用煤。