高位瓦斯抽放钻孔在降低综采工作面瓦斯浓度中的应用     

王永军  刘文兰 《中国煤炭地质》2008,(9):74-75

林南仓属于低瓦斯矿井,但存在高瓦斯区域。煤层和采空区是瓦斯的主要来源,尤以采空涌出量大,给煤矿生产和安全带来了极大隐患。通过在1129综采工作面风道施工高位瓦斯孔,把钻孔打到采空区一侧煤层顶板以上冒落裂隙带内,用钻孔进行瓦斯抽放,使采空内的瓦斯通过裂隙带沿钻孔抽出,有效降低综采工作面瓦斯浓度,保证综采工作面正常回采和安全生产。  相似文献   

Influence of karst hydrology on water quality management in southeast South Australia     

A. J. Emmett  A. L. Telfer 《Environmental Geology》1994,23(2):149-155

Southeast South Australia has large reserves of potable groundwater, generally close to the surface. European settlement has had a major impact on groundwater quality due to the presence of extensive karst in the unconfined aquifer. Historically, industries such as cheese factories were often sited close to karst features (e.g. caves and sinkholes) because they provided a convenient means of waste disposal. Although most have long since closed, they have left a legacy of pollution plumes of varying sizes. In Mount Gambier, the main regional centre, the presence of both exposed and subterranean karst features provided a perfect system for the disposal of stormwater. Prior to the provision of a sewerage system within Mount Gambier, all toilet and household wastewaters were disposed to ground. These activities and the subsequent problems that began emerging in the 1960s have led to a concerted effort over the last 20 years to change the philosophy of waste disposal and to generate an understanding and responsibility by those who live in the region and depend on groundwater for the major part of their water supply. Mount Gambier's water supply comes from the Blue Lake. Groundwater inflow from a highly karstic Tertiary limestone aquifer provides 90% of the recharge to the Blue Lake. The lake is a high-value resource in a high-risk environment and in order to minimize this risk, a water-quality management plan for the lake is currently being developed.  相似文献   

An evaluation of residential air radon concentrations and related variables in southeast Michigan,USA     

L. G. Kodosky 《Environmental Geology》1994,23(1):65-72

Analysis of 153 residential air radon (Rn-222) screening measurements from southeast Michigan indicates that basements host Rn levels two to three times higher than upper-level rooms. Compared to unfinished basements, finished (e.g., paneled walls, tiled floors) basements apparently reduce indoor air Rn levels while partially finished basements may not. Factor analysis of residence questionnaire data explains 59 percent of the Rn data variance. The volume of pathways (e.g., foundation cracks/holes, uncapped sumps) allowing Rn seepage into the dwelling controls the largest portion, 23 percent, of the explained data variance. The residence water source explains 11 percent of the Rn data variance. Groundwater Rn levels contribute to the air Rn data variability, but the study data cannot quantitatively assess this contribution. Seven percent of the Rn data variance is likely controlled by house depressurization facilitated by residence structural properties. Residences with foundation cracks or poorly sealed joints and low-volume indoor-outdoor air exchange are more prone to this effect. Eighteen percent of the explained Rn data variance correlates with the residence's primary heat source. Evidently, operating combustion sources also induce house depressurization and allow Rn to be drawn into the house through entry paths. Twenty-four percent of the analyses equal or exceed 4 pCi/1 Rn. In residences occupied 5 years by the same individuals, 17 percent of the Rn data are 4 pCi/l; here the arithmetic mean air Rn level is 8.3 pCi/l and the average occupancy period 17.4 years.  相似文献   

金沙本底站空气质量与颗粒物浓度变化特征分析     

吴栋桥  周登 《气象科学进展》2021,(1)

利用华中区域代表性站点金沙国家大气本底站2007—2018年的PM_2.5、PM₁₀颗粒物质量浓度数据,2019年3月—2019年6月反应性气体数据,对华中区域空气质量进行整体评价,并分析了颗粒物浓度的变化特征及其影响因素。结果表明,反应性气体CO、SO₂、NO、NO₂质量浓度其日平均最大值、平均值均达到一级标准,O₃日平均值超标率为10.6%,PM_2.5超标率为18%,PM₁₀超标率为17%。从颗粒物质量浓度多年变化来看,2007—2013年金沙站大气颗粒物质量浓度属于上升趋势,2013年至今质量浓度呈现下降趋势,风向风速也在一定程度上影响颗粒物的来源。  相似文献   

编译BASIC语言编程质量的控制     

秦志远 《测绘学院学报》1992,(2)

本文利用编译BASIC语言具有的某些特殊功能,结合具体课题研究实践,从编程技术的模块化、坚固性和可用性三方面进行了实验,采用覆盖技术、“出误陷阱”等技术,使得在较小的内存中运行较大的程序并捕获可能发生的各种随机事件,达到了控制编程质量的目的。  相似文献   

岩溶区集中式饮用水源地水质评价与保护——以毕节市倒天河水库和利民水库为例     

莫世江  刘勇  张鹏飞  丁卫红 《云南地理环境研究》2006,18(5):24-27

采用SPSS软件，对2003年01月至2004年12月期间，倒天河水库和利民水库逐月水质监测数据进行数理统计分析，结果表明毕节市饮用水水质污染有较明显的季节变化和空间差异；且不同污染物对水体污染的贡献率各不相同，总磷和粪大肠菌群所占份额最大，方差累积贡献率达77％。在此基础上，利用加权综合污染指数对水体水质污染现状进行综合评价，结果显示倒天河水库和利民水库，水质污染总体较轻．饮用水水质符合《地表水环境质量标准（GB3838—2002）》中Ⅲ类水质标准；最后提出加大水环境保护的建议。  相似文献   

20世纪末广东省三大城市大气环境质量综合评价——改进密切值法的扩展应用     

曹建荣  刘衍君 《云南地理环境研究》2006,18(5):34-37

大气环境质量综合评价是一个城市环境质量考核的重要指标，改进的密切值法是其中一种切实可行的评价方法。通过对1991-2000年10年间广东省三大城市——广州、深圳和珠海的大气环境质量进行综合评价，发现20世纪末，大气环境质量最好的是珠海市，最差的是广州市。与广东省平均水平相比、三大城市中。广州市污染程度高于全省平均水平。从空气环境质量的变化趋势来看，自1997年开始，三大城市大气环境质量趋于好转，为新世纪城市空气环境质量改善提供了良好的基础。  相似文献   

Determination of potential hazardous elements in Can coals （Canakkale- Turkey）-I     

Gulbin Gurdal Alper Baba 《中国地球化学学报》2006,25(B08):52-53

It is known that the increasing use of coal as an energy source led to the growing environmental and health problems. But comprehensive knowledge of coal quality parameters may help to reduce some of these problems. The Canakkale-Can coalfield is located in the western part of Turkey, whose reserves are estimated at 69.3 billion tons, mainly used in the industry in the neighboring areas, specifically for the Can Thermal Power Plant. The aim of this study is to determine the coal quality parameters and examine the origin and distributions of potentially toxic trace elements in lignite which may produce environmental and health hazards in the area. The coal samples were collected from different parts of the coalfield in Can. Proximate and ultimate analyses, sulfur form analyses, X-ray powder diffraction （XRD）, inductively coupled plasma-mass spectrometry （ICP-MS）, and scanning electron microscopy （SEM） were performed on those samples to determine the geochemical profile of hazardous elements.  相似文献   

Analysis of the effect of geology, soil properties, and land use on groundwater quality using multivariate statistical and GIS methods     

Jin-Soo Lee Kyung-Seok Ko Tong-Kwon Kim Jae Gon Kim Seong-Hyun Cho In-Suk Oh 《中国地球化学学报》2006,25(B08):152-152

The regional survey of groundwater used as a small water supply system was performed to know the effect of geology, soil properties and land use on groundwater quality at Nonsan City, Korea. A total of 126 groundwater samples were collected and analyzed at the study area. The multivariate statistical methods, principal components analysis and discriminant analysis, and GIS technique were used for the quantitative interpretation of groundwater quality. The study area is mainly composed of Precambrian gneiss, Jurassic granite, and Cretaceous volcanics, and metasedimentary rocks of the Ogcheon zone. The land use was grouped as paddy, upland, grassland, resident, point source, industrial area, and water system. The soil properties were classified as 4 major groups, Entisols, Alfisols, Inceptisols, and Ultisols, by the degree of development, and reclassified as 11 subgroups. The modified and simplified geologic map, soil map, and land use map were made by using ARCGIS soft-ware. The area of geology, soil property, and land use affecting the groundwater quality for each well were also calculated by ARCGIS soft-ware to acquire the quantitative parameters for multivariate statistical analysis. The monitoring results of groundwater in the study area showed that 13%-21% of the groundwater samples exceeded the portable water guideline and the main causes were turbidity, bacteria, arsenic and nitrate-N. The spatial distribution of each component showed the close relationship between groundwater quality and geology reflecting the topography, land use.  相似文献   

泥晶灰岩地层孔壁坍塌掉块现象及处理          下载免费PDF全文

杜金云 《探矿工程》2006,33(8):51-52

在灰岩地区钻探施工过程中，常见孔壁坍塌、掉块现象，尤其在含泥晶灰岩地层分布区钻进过程中，这种现象尤为突出，轻则影响钻探施工效率，重则造成钻探孔内事故。针对孔内坍塌、掉块现象的征兆及特点，提出了相对应的处理办法。  相似文献