共查询到19条相似文献，搜索用时 500 毫秒
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为了探明地下采空区的分布范围和埋深,应用高密度电阻率法探测陡倾煤层采空区,根据视电阻率二维反演断面图,分析电阻率异常形态、高低阻分布等特征,推断出采空塌陷和第裂缝的位置,经钻探证实,推断结果与实际情况相吻合,高密度电阻率法是准确探测陡倾煤层采空区空间形态特征及其塌陷变形影响范围行之有效的方法。 相似文献
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电阻率法在防治莱州湾地区海水入侵中的应用 总被引：4，自引：0，他引：4
阐述电阻率法在莱州湾地区海水入侵防治研究中应用的理论依据、监测指标.对海、咸水入侵区地层电阻率的变化规律,咸、淡水界面的确定,圈定海水入侵通道及界面运移规律做了分析. 相似文献
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本文基于基础资料收集,通过高密度电阻率法并结合钻探验证工程,对山东莱州小浞河铁矿开采形成的采空区进行勘查。勘查成果表明,因充水,小浞河铁矿采空区电阻率值明显低于周围岩层,在高密度电法视电阻率反演断面图上均表现为漏斗状低阻异常,并且异常体分布相对规则、连续,与磁铁矿体及其采准巷道工程较一致。经钻探工程进一步验证,物探解译推断的采空区位置与钻探揭露深度较为吻合,表明高密度电阻率法在铁矿采空区勘查中具有较高的可行性和实用性。基于Voxler软件平台,综合基础地质资料以及钻探验证结果等,对高密度电法测量成果三维可视化可有效快捷地圈定采空区范围,为进一步的灾害防治提供有利依据。 相似文献
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从点源场的边值问题出发,利用有限元推导了井地电法和高密度电法2.5维的详细解法,并编制了相应的程序。利用均匀半空间的地电模型进行了正演计算,并与地下真实电阻率进行了对比分析,验证了算法的正确性。在此基础上对均匀介质中存在对称高阻体和边缘高阻体的模型,进行正演模拟,分别得到其井地电法的视电阻率断面图和高密度电法的视电阻率断面图。结果表明,结合两种方法可以对地下存在的高阻异常体进行有效精确地探测。 相似文献
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海水入侵的同位素研究 总被引：8，自引：0，他引：8
本文用同位素方法研究了我国莱州湾海水入侵的成因及变化发展趋势。结果表明，在莱州湾西部的广饶地区属于卤水（古海水）入侵区，在莱州湾东部的龙口地区属于现代海水入侵区。
而在莱州地区则既存在着海水入侵又存在着卤水入侵。 相似文献
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潘三矿12318面在回采过程中发现一陷落柱,为查明其分布范围、赋水、导水情况,采用井下瞬变电磁法进行探测。基于矿井内切眼、风巷、机巷的位置,采用U型观测系统布设了三条测线。将不同方向视电阻率断面图进行对比,解释该陷落柱距风巷的垂直距离在70m左右。依据视电阻率断面图高阻值在面内延伸的形态,确定了该陷落柱的长轴方向及分布范围,并断定其无富水异常。经钻孔验证,与解释结果一致,表明瞬变电磁法应用于井下进行陷落柱探测具有较高的准确性。 相似文献
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准确确定咸淡水界面位置是评价咸水入侵范围的前提。对于咸淡水界面位置的确定,传统研究以水化学法和物探法为主。为克服单一使用传统方法造成的人力、物力和财力的大量浪费,以莱州湾西南岸广饶县小清河以南咸水入侵区为研究对象,在综合分析研究区地下水开采现状、水化学监测结果的基础上,选择3个典型断面,采用水化学法中的野外现场电导率法,快速判断咸淡水界面大致位置（某两眼监测井之间）;再在一咸一淡的两眼监测井之间,采用高密度电阻率法快速、准确地确定咸淡水界面的空间分布。结果表明：该地区的地下水电导率若大于1.61 mS/cm,即可认为此处受到咸水入侵;咸淡水界面位置的视电阻率特征值为11~13 Ω·m,咸淡水界面附近咸水体呈舌状入侵并主要发生在地表以下13 m内的浅层地下水中。 相似文献
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基于MIKE3研究扰动底层盐水楔实现抑制咸潮上溯的最优化方案。结果表明,在河道底部喷水扰动盐水楔可以有效减弱底层盐水浓度,且存在最优喷水流量与最优喷水点。当喷水流量小于该值时,咸潮上溯距离随流量的增大而减小,当大于该值时,咸潮上溯距离随流量的增大反而会增大;最优喷水流量从小潮到大潮逐渐增加,且随着径流量的增大而减小,如径流量为500 m/s~3时,小、中、大潮期间的最优喷水流量分别为20 m/s~3、20 m/s~3和25 m/s~3,减少的咸潮上溯距离分别为3.82 km、3.40 km和1.18 km。随着径流量增大,取得最佳抑咸效果的最优喷水点位置逐渐向下游移动。针对珠江河口的特殊径潮环境,盐水楔扰动的抑咸效果在小潮和中潮期间较好,在大潮期间相对较差。 相似文献
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Hydrogeology Journal - During the past few years, the number of regional and national assessments of groundwater quality in regard to saltwater intrusion in coastal aquifers has increased steadily.... 相似文献
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Saltwater intrusion in coastal regions of North America 总被引：7，自引：3，他引：4
Saltwater has intruded into many of the coastal aquifers of the United States, Mexico, and Canada, but the extent of saltwater intrusion varies widely among localities and hydrogeologic settings. In many instances, the area contaminated by saltwater is limited to small parts of an aquifer and to specific wells and has had little or no effect on overall groundwater supplies; in other instances, saltwater contamination is of regional extent and has resulted in the closure of many groundwater supply wells. The variability of hydrogeologic settings, three-dimensional distribution of saline water, and history of groundwater withdrawals and freshwater drainage has resulted in a variety of modes of saltwater intrusion into coastal aquifers. These include lateral intrusion from the ocean; upward intrusion from deeper, more saline zones of a groundwater system; and downward intrusion from coastal waters. Saltwater contamination also has occurred along open boreholes and within abandoned, improperly constructed, or corroded wells that provide pathways for vertical migration across interconnected aquifers. Communities within the coastal regions of North America are taking actions to manage and prevent saltwater intrusion to ensure a sustainable source of groundwater for the future. These actions can be grouped broadly into scientific monitoring and assessment, engineering techniques, and regulatory approaches. 相似文献
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塔里木盆地古近系、白垩系地层含膏、含盐,气显示活跃,固井难度大。在总结前期微膨胀胶乳防窜水泥浆体系固井失利原因的基础上,重点考虑地层岩性特征,以提高二界面胶结质量为目的,优选出微膨胀防窜盐水水泥浆体系。该体系具有API失水量小、SPN值小、水泥石强度大的特点,经现场应用,封固井段固井质量优良,表明该体系有广泛推广的前景。 相似文献
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Luke R. Chambers Ellery D. Ingall Emily M. Saad Amelia F. Longo Masayuki Takeuchi Yuanzhi Tang Claudia Benitez-Nelson Sheean T. Haley Sonya T. Dyhrman Jay Brandes Aron Stubbins 《Aquatic Geochemistry》2016,22(5-6):555-572
Complexities associated with dissolved organic matter (DOM) isolation from seawater have hampered compositional characterization of this key component of global carbon and nutrient cycles. DOM isolation efficiency by electrodialysis (ED) from salt-containing waters was optimized and evaluated on samples including coastal ocean seawater, open ocean seawater, artificial seawater from axenic cultures of marine phytoplankton, and artificial seawater samples containing standard compounds of different molecular sizes and charge. ED was performed with a system optimized for processing 2–10 L sample volumes. Additionally, the combination of ED and solid-phase extraction, using Bond Elut PPL exchange resin, was evaluated. Using only ED, the following DOC recoveries were achieved: coastal seawater, 71.3 ± 6.5 %; open ocean, 50.5 ± 3.1 %; phytoplankton cultures, 70.3 ± 12.5 %; glucose, 90.2 ± 2.1 %; EDTA, 67.5 ± 9.9 %; and vitamin B12, 98.3 ± 1.6 %. With the combination of PPL and ED techniques, an average DOC recovery of 76.7 ± 2.6 % was obtained for coastal seawater, but this recovery was not statistically different from seawater recoveries using only ED. Comparison of C/N ratios and fluorescence excitation emission matrices taken at the beginning and end of the recovery process for coastal samples processed using only ED indicated that the final recovered material was representative of the DOM present in the original samples. Typical recoveries using combined PPL and ED exceed those of previous isolation methods. 相似文献