首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 359 毫秒
1.
This study constructs a hazard map for ground subsidence around abandoned underground coal mines (AUCMs) at Samcheok City in Korea using a probability (frequency ratio) model, a statistical (logistic regression) model, and a Geographic Information System (GIS). To evaluate the factors related to ground subsidence, an image database was constructed from a topographical map, geological map, mining tunnel map, Global Positioning System (GPS) data, land use map, lineaments, digital elevation model (DEM) data, and borehole data. An attribute database was also constructed from field investigations and reports on the existing ground subsidence areas at the study site. Nine major factors causing ground subsidence were extracted from the probability analysis of the existing ground subsidence area: (1) depth of drift; (2) DEM and slope gradient; (3) groundwater level, permeability, and rock mass rating (RMR); (4) lineaments and geology; and (5) land use. The frequency ratio and logistic regression models were applied to determine each factor’s rating, and the ratings were overlain for ground subsidence hazard mapping. The ground subsidence hazard map was then verified and compared with existing subsidence areas. The verification results showed that the logistic regression model (accuracy of 95.01%) is better in prediction than the frequency ratio model (accuracy of 93.29%). The verification results showed sufficient agreement between the hazard map and the existing data on ground subsidence area. Analysis of ground subsidence with the frequency ratio and logistic regression models suggests that quantitative analysis of ground subsidence near AUCMs is possible.  相似文献   

2.
Hazard maps of ground subsidence around abandoned underground coal mines (AUCMs) in Samcheok, Korea, were constructed using fuzzy ensemble techniques and a geographical information system (GIS). To evaluate the factors related to ground subsidence, a spatial database was constructed from topographic, geologic, mine tunnel, land use, groundwater, and ground subsidence maps. Spatial data, topography, geology, and various ground-engineering data for the subsidence area were collected and compiled in a database for mapping ground-subsidence hazard (GSH). The subsidence area was randomly split 70/30 for training and validation of the models. The relationships between the detected ground-subsidence area and the factors were identified and quantified by frequency ratio (FR), logistic regression (LR) and artificial neural network (ANN) models. The relationships were used as factor ratings in the overlay analysis to create ground-subsidence hazard indexes and maps. The three GSH maps were then used as new input factors and integrated using fuzzy-ensemble methods to make better hazard maps. All of the hazard maps were validated by comparison with known subsidence areas that were not used directly in the analysis. As the result, the ensemble model was found to be more effective in terms of prediction accuracy than the individual model.  相似文献   

3.
This study shows the construction of a hazard map for presumptive ground subsidence around abandoned underground coal mines (AUCMs) at Samcheok City in Korea using an artificial neural network, with a geographic information system (GIS). To evaluate the factors governing ground subsidence, an image database was constructed from a topographical map, geological map, mining tunnel map, global positioning system (GPS) data, land use map, digital elevation model (DEM) data, and borehole data. An attribute database was also constructed by employing field investigations and reinforcement working reports for the existing ground subsidence areas at the study site. Seven major factors controlling ground subsidence were determined from the probability analysis of the existing ground subsidence area. Depth of drift from the mining tunnel map, DEM and slope gradient obtained from the topographical map, groundwater level and permeability from borehole data, geology and land use. These factors were employed by with artificial neural networks to analyze ground subsidence hazard. Each factor’s weight was determined by the back-propagation training method. Then the ground subsidence hazard indices were calculated using the trained back-propagation weights, and the ground subsidence hazard map was created by GIS. Ground subsidence locations were used to verify results of the ground subsidence hazard map and the verification results showed 96.06% accuracy. The verification results exhibited sufficient agreement between the presumptive hazard map and the existing data on ground subsidence area. An erratum to this article can be found at  相似文献   

4.
探地雷达在探测地下采空区范围中的应用   总被引:11,自引:1,他引:10  
由放心弃的地下采空区引起的地面沉陷,已成为一种典型的地质灾害,严重影响工程建设的顺利进行。为了采取相应的治理措施,查明地下采空区的埋深及分布范围显得十分重要通过实例,简述探地雷达在探测地下采空区范围中的应用,探测目的在于确定地下采空区的深度,查明地下采空区的范围,为公路建设选线提供可靠依据。  相似文献   

5.
This study deals with the characteristics of subsidence and the relationships between the subsidence factors over abandoned coal mines in South Korea. The subsidence factors that were investigated were the dip angle and thickness of the coal bed, mining depth, depth of subsidence, and subsidence area in 548 cases of subsidence that occurred throughout the country. A close relationship between the type of subsidence and mining method was identified. There was an intimate relation between the depth of subsidence and the dip angle of the coal bed, while the subsidence area proved to be in proportion to the thickness of the coal bed and mining depth and was in inverse proportion to the dip angle of the coal bed.  相似文献   

6.
In Korea most of the old mine workings were worked with room and pillar method or sublevel caving method and today they possess great possibility of surface subsidence especially for shallow depth mines. In most of the cases, mine roadways, rooms and pillars are irregular in shape and information about the local geology is uncertain. For these reasons, it is difficult to standardize the estimating method of subsidence especially sinkhole type over abandoned mine area. This paper describes the application procedure for the fuzzy reasoning techniques to analyze the possibility of sinkhole occurrences over abandoned mines. This technique is implemented in software which can simplify the analysis procedure and present the possibility of sinkhole subsidence without having precise information about local geological/mining conditions. This technique has been applied to forecast sinkhole possibilities at Bonghwa site where a massive sinkhole has already been occurred.  相似文献   

7.
Various groundwater potential zones for the assessment of groundwater availability in the Bojnourd basin have been investigated using remote sensing, GIS, and a probabilistic approach. Five independent groundwater factors, including topography, ground slope, stream density, geology units, lineament density, and a groundwater productivity factor, i.e., springs’ discharge, were applied. Discharge rates of 226 springs over the area were collected, and the probabilistic model was designed by the discharge rates of springs as the dependent variable. For training the probabilistic model, a ratio of 70/30% of springs’ discharge was applied and discharge rates of 151 springs were selected to randomly train the model. The frequency ratio for each factor was calculated, and the groundwater potential zones were extracted by summation of frequency ratio maps. The groundwater potential map was also classified into four classes, viz., “very good” (with a frequency ratio of >6.75), “good” (5.5FR6.75), “moderate” (4.75FR5.5), and “poor” (FR4.75). Then, the model was verified based on a success-rate curve method which resulted in obtaining an accuracy ratio of 75.77%. Finally, sensitivity analysis was applied by a factor removal method in five steps. Results reveal that topography factor has the biggest effect on the groundwater potential map and removing this factor eventuates in the lowest accuracy of the final map (AUC = 63. 73%). The groundwater potential map is fairly affected by removing the lineament density factor with an accuracy of 68.80%. Removing the lineament density factor has the lowest effect on the final map with accuracy of 68.80%.  相似文献   

8.
The aim of this paper is to use a knowledge-driven expert-based geographical information system (GIS) model coupling with remote-sensing-derived parameters for groundwater potential mapping in an area of the Upper Langat Basin, Malaysia. In this study, nine groundwater storage controlling parameters that affect groundwater occurrences are derived from remotely sensed imagery, available maps, and associated databases. Those parameters are: lithology, slope, lineament, land use, soil, rainfall, drainage density, elevation, and geomorphology. Then the parameter layers were integrated and modeled using a knowledge-driven GIS of weighted linear combination. The weightage and score for each parameter and their classes are based on the Malaysian groundwater expert opinion survey. The predicted groundwater potential map was classified into four distinct zones based on the classification scheme designed by Department of Minerals and Geoscience Malaysia (JMG). The results showed that about 17% of the study area falls under low-potential zone, with 66% on moderate-potential zone, 15% with high-potential zone, and only 0.45% falls under very-high-potential zone. The results obtained in this study were validated with the groundwater borehole wells data compiled by the JMG and showed 76% of prediction accuracy. In addition statistical analysis indicated that hard rock dominant of the study area is controlled by secondary porosity such as distance from lineament and density of lineament. There are high correlations between area percentage of predicted groundwater potential zones and groundwater well yield. Results obtained from this study can be useful for future planning of groundwater exploration, planning and development by related agencies in Malaysia which provide a rapid method and reduce cost as well as less time consuming. The results may be also transferable to other areas of similar hydrological characteristics.  相似文献   

9.
The Ground Penetrating Radar (GPR) is a newly developing geophysical tool for imaging the sub-surface and is potentially useful in groundwater exploration. We test its usefulness in characterizing a groundwater rich lineament near Gajularamaram in the Hyderabad granite terrain, where groundwater is limited to soil, weathering zone and lineaments. The lineament is 2 km long and 50–100 m wide, and oriented in WNW-ESE direction. It is characterized by many closely spaced sub-vertical fractures and faults, majority of which are parallel to the lineament. On either sides of the lineament, sub-horizontal sheet joints are abundant. The lineament is saturated with groundwater that discharge as springs at some places. About 450 m long, 400–100 MHz GPR data (~5–30 m depth) were acquired along five profiles across the lineament. In the lineament, soil thickness varies from ~0.5 m to 5 m, and is underlain by weathered granite. In the WNW part, a thick weathering zone (~15 m) is present and a 10 m wide vertical anomaly zone (lineament) is also present. The presence of shallow reflectors at 1 m depth in the lineament is attributed to the groundwater surface. The GPR images reveal many sub horizontal to gently dipping reflectors, which are interpreted to be the sheet joints. The GPR data clearly reveal the saturated lineament, from which groundwater may migrate laterally to long distance through the sheet joints. We demonstrate the GPR as a rapid geophysical tool that can be used successfully to explore the nearsurface groundwater.  相似文献   

10.
Surface water and groundwater samples were collected from 20 locations, situated in the vicinity of the abandoned coal mine fields south of Bochum. The main objective of this research is to assess the environmental impacts of these mines on the surface water and groundwater quality as well as to determine the factors controlling these impacts. The water samples were collected from stream sources, groundwater, surface water and engineered channels during April 2011. Physicochemical parameters were measured during fieldwork. Water samples were analysed for major ions and aluminium, iron, manganese, ferrous iron, zinc and hydrogen sulphide. The hydrochemistry of the surface water and the groundwater of this area is characterized by near-neutral to alkaline conditions, represented by predominance of calcium bicarbonate and sometimes calcium sulphate water types. Hence, the surface water and the groundwater quality in this region is significantly affected by abandoned coal mines. These effects resulted from oxidation of iron disulphide minerals that release iron, sulphate and hydrogen. The presence of carbonate-rich materials, which contained within the landfilling materials, has led the releasing of calcium, magnesium and bicarbonate. These materials could be the main source responsible for raising the alkalinity of the affected water. The environmental hazard of the abandoned coal mines in this area is related to the high concentration of Fe especially in the groundwater that possess the highest Fe concentration compared to other water sources: the Fe is 18 times larger than the allowed value in drinking water. Significant spatial variations of the water pollution were noted in this study. For this reason, the environmental hazards of the abandoned coal mines in Germany should be considered at closure of coal mines in the near future. Otherwise, these mines will be sources of environmental threats unless all necessary measures are taken to reduce their impact.  相似文献   

11.
The study uses the technique of factorial design for analysis of factors governing secondary dispersion of As in an auriferous Archean greenstone belt. Details of the sampling procedure and analytical techniques used for As in groundwater and soil of the Hutti–Maski schist belt are discussed in Part I of the paper in this issue. The main effects and interactions of topographic slope, drainage texture, proximity to lineament, depth of water table and soil types have been considered. The study shows that secondary dispersion of As is governed by proximity to lineament and factors that govern drainage and ground water movement. The factors retained were used to predict As values using a response surface model obtained by least square fitting using orthogonal polynomials. The goodness of fit of the model shows that the factors identified explain the secondary dispersion of As adequately.  相似文献   

12.
Information on subsidence in a water area caused by mining has a great value on the research of the mining subsidence law of a mining area with a high groundwater level in Eastern China. Based on the measured data of the subsidence area without water, the data extraction of subsidence in a water area is studied in this paper, with a support vector machine, as subsidence in such an area is difficult to measure. Research shows that the training sample number and dimension should be strengthened by increasing the measuring times or using the interpolation method to obtain ideal prediction accuracy. The ε-Support Vector Regression model with three parameters optimized by the genetic algorithm or the particle swarm optimization algorithm is suitable to extract subsidence information in a water area caused by mining, and the algorithm is accomplished on Matlab. Data analysis showed that when the water is deeper than 1.8 m and the distance is over 60 m from the measured points, the prediction error of test samples will exceed 10 % out of all measured results, meaning that practicability is relatively poor; while water depth is <0.8 m or the distance is lower than 60 m from the measured points, the prediction error of test samples will be calculated to <5 % of the measured results, the prediction results can be used.  相似文献   

13.
Mining subsidence and its effect on the environment: some differing examples   总被引:14,自引:3,他引:11  
 The impact of mining subsidence on the environment can occasionally be very catastrophic, destroying property and even leading to the loss of life. Usually, however, such subsidence gives rise to varying degrees of structural damage that can range from slight to very severe. Different types of mineral deposits have been mined in different ways and this determines the nature of the associated subsidence. Some mining methods result in contemporaneous subsidence whereas, with others, subsidence may occur long after the mine workings have been abandoned. In the latter instance, it is more or less impossible to predict the effects or timing of subsidence. A number of different mineral deposits have been chosen to illustrate the different types of associated subsidence that result and the problems that arise. The examples provided are gold mining in the Johannesburg area; bord and pillar mining of coal in the Witbank Coalfield, South Africa; longwall mining of coal in the Ruhr district; mining of chalk and limestone in Suffolk and the West Midlands, respectively; and solution mining of salt in Cheshire. These mineral deposits have often been worked for more than 100 years and, therefore, a major problem results from abandoned mines, especially those at shallow depth, the presence of which is unrecorded. Abandoned mines at shallow depth can represent a serious problem in areas that are being developed or redeveloped. Abstraction of natural brine has given rise to subsidence with its own particular problems and cannot be predicted. Although such abstraction is now inconsequential in Cheshire, dereliction associated with past subsidence still remains. Received: 21 October 1999 · Accepted: 14 February 2000  相似文献   

14.
济宁市区地面沉降及防冶措施研究   总被引:1,自引:1,他引:0  
地面沉降是近年来我国和世界上许多城市出现的重要的地质灾害之一,济宁城区1988年发现地面沉降,并以25.2mm/a沉降速度发展。本文从新构造运动、地下水开采、第四系砂土特征等方面,分析了济宁城区地面沉降的产生原因,指出新构造运动与超量抽取地下水是造成济宁城区地面沉降主要原因;通过对地下水开采量的变化趋势,中、深层地下水的补给条件的分析,对地面沉降变化趋势作出了预测;根据济宁市地处济宁矿区的特点,提出了综合利用地下水、防治济宁城区地面沉降进一步发展的对策。  相似文献   

15.
Information on the distribution of subsurface temperature and hydraulic heads at 24 observation wells in and around the Tokyo Lowland, the eastern part of the Tokyo Metropolitan area, were examined to make clear the relationship between groundwater and the subsurface thermal environment in the urban area. Minimums in temperature–depth logs due to subsurface temperature increasing at shallow parts were recognized in 21 wells. This fact shows subsurface temperature is affected by ground surface warming in almost all of this area. Deeper than minimums, where the effects of surface warming became relatively small, regional variation is observed as follows: high temperatures are shown in the central part to the southern part, and low temperatures shown in the inland to eastern part. The high temperature area corresponds to an area where the lower boundary of groundwater flow is relatively shallow. This area corresponds also to an area with severe land subsidence resulting from excessive groundwater pumping. It is considered that this high temperature area is formed by the effects of upward groundwater flow affected by hydrogeological conditions and pumping. On the other hand, a comparison between past data (1956–1967) and present data (2001–2003) revealed widespread decreasing temperature in the inland area. This is explained by downward groundwater flow based on an analysis of temperature–depth logs. This fact suggests that subsurface temperature is not only increasing from the effects of surface warming but also decreasing from the effects of groundwater environment change due to pumping.  相似文献   

16.
金沙洲可溶性灰岩分布面积广,岩溶洞隙发育,洞隙及地下水的连通性强,上覆第四系松散土体中软土广泛分布,客观存在岩溶地面塌陷及地面沉降的地质环境条件。2007年4月起,受某高铁隧道施工抽排地下水的影响,金沙洲地下水出现异常波动,引发了地面塌陷及地面沉降。文章根据监测数据,经对比分析结果表明,区内岩溶地面塌陷及地面沉降受控于地下水位的变化,地下水位波动至基岩面附近时,是地面塌陷较活跃的时期,地面沉降与地下水位变化呈正向相关。文章进一步对地面沉降与地下水位变化关系的机理进行了探讨,认为目前地下水位尚未恢复正常的区域仍存在地面塌陷及地面沉降的隐患。  相似文献   

17.
唐山南部沿海地区是唐山市地面沉降灾害较严重的地区,地面沉降的快速发展对唐山世界级重化工业基地的功能发挥构成严重威胁,全面了解唐山南部沿海地区地面沉降的分布演化态势及其发育主导因素至关重要。基于中高分辨率雷达数据,采用PSInSAR技术获取唐山南部沿海地区地面沉降场的分布及演化信息,可以发现这一地区的区域地面沉降漏斗与地下水位下降漏斗具有良好的对应关系,且沉降区范围沿区内基底断裂带一侧展布。但在曹妃甸工业区,地面沉降特征与过量开采地下水引起的地面沉降特征有所不同,地面沉降区呈点状、斑状分布,沉降区范围较小,沉降中心的沉降梯度大。据调查,特殊的地质环境是该区地面沉降发育的基础条件,地下水超采、大规模工程扰动是诱发和加剧地面沉降的外在动力。  相似文献   

18.
贵州是我国主要煤炭产地之一, 成本与地方条件的限制使贵州贞丰县山区出现大量的非法小煤窑, 其大多开采一年、半年便废弃煤矿, 调查其地下开采范围对矿区生态修复、土地资源再利用、煤矿越界开采监测等有一定意义。本文利用升、降轨观测共16期3 m空间分辨率的L波段PALSAR-2影像为数据源, 在贵州省贞丰县采用InSAR技术对煤矿采空区开展了短期动态地表沉降监测, 结合研究区地质条件、地下开采条件、开采时间、范围等信息, 计算了该地区煤矿开采沉陷影响角的规律与变形时间滞后关系; 而后利用上述参数及地表变形信息, 在其附近一处废弃煤矿, 对其地下采空范围及开采时间进行反演:(1)研究区煤炭开采走向影响角为83°、上山影响角75°、下山影响角80°, 地表变形时间与地下开采时间差约1个月; (2)计算反演出研究区废弃煤矿地下开采范围为380 m×150 m; (3)在反演煤矿采区, 对比FLAC3D数值模拟计算结果和野外现场调查, 验证了InSAR计算结果基本准确, 验证了此方法对煤矿采区反演的合理性与可靠性。  相似文献   

19.
黑龙江省地下水资源比较丰富,目前总体开发利用程度较低,开采潜力很大,但各地开发利用程度有较大区别,哈尔滨、大庆等地区地下水超采较严重,形成了区域性的水位降落漏斗,最大漏斗面积达4500km2,最大水位降深达40余m,单井涌水量衰减40%以上;鸡西等矿区大量疏干地下水,使水源濒于枯竭;哈尔滨、大庆等城市已出现地面沉降迹象.这些问题的产生制约着当地经济的发展.科学、合理地开发、保护地下水资源已是当务之急.对严重超采区要控制开采,调整用水结构、分质供水、科学管水、节约用水.此外应充分利用矿区排出的地下水,变害为利.加强地下水的监测和研究工作,及时解决开发中的问题.  相似文献   

20.
席新海  姚青  王喜军 《探矿工程》2014,41(11):60-62
郑东新区经济的高速发展,城镇化进程的不断加快,使得该地区资源、环境与发展问题日益突出。特别是黄河沿岸水资源的集中开采,集中的渔业地下水开采和基坑降水,已经引发了大面积的地面沉降,对京广高铁的正常运行带来影响。在全面调查了郑东新区的地质背景、自然地理及京广高铁沿线地下水开采情况基础上,结合本地区地面沉降发育的基本状况,详细分析研究了郑东新区地面沉降的形成机制和重要影响因素,并提出了相应的保护措施。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号