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1.
岩溶介质具有较强的非均质性,其地表及地下的岩溶结构形态多样。通过对钻孔结构描述、钻孔水物化性质分析,不仅能够掌握区域上岩溶含水层的结构特征,而且对于岩溶地下水演化过程的揭示亦有重要作用。文章以桂林岩溶水文地质试验场西南部峰丛山区与峰林平原交界处的钻孔为例,通过野外便携式多参数仪原位测试钻孔垂向水物化指标（pH值、水温T、电导率EC）,探索浅部（地面以下约50 m内）地下岩溶较为发育条件下钻孔水物化指标的垂向变化特征,揭示岩溶介质非均质性对钻孔垂向水物化指标的影响。结果表明:岩溶地区小范围内不同钻孔间的水物化性质有所差异,且岩溶发育相似的钻孔（如ZK4/ZK5、ZK7/ZK8）,其水物化指标垂向变化具有一定的相似性,但不同指标（T、pH、EC）的变化幅度存在差异;钻孔水物化性质受到试验场区岩溶介质结构非均质性的控制,即岩溶介质结构影响了地下水的赋存条件和水力联系而导致水物化性质的差异;在对岩溶地区地下水物化性质进行研究时应充分考虑岩溶介质的非均质性特征,根据实际的水文地质条件选取具有代表性的钻孔含水段进行取样和监测。 相似文献
2.
The objective of this study was to assess the subsurface strata and groundwater situation of Olomoro, Nigeria using borehole logging and electrical resistivity techniques. The borehole logging consisting of resistivity and spontaneous potential logs were conducted by using the Johnson Keck logger on a drilled well in the study area. The electrical resistivity survey involving 17 vertical electrical soundings (VES) with a maximum current electrode spacing of 100 to 150 m was conducted using the Schlumberger electrode configuration. Analysis of the well cuttings revealed that the lithology of the subsurface consist of topsoil, clay, very fine sand, medium grain sand, coarse sand and very coarse sand. Results of the downhole logging also revealed that the mean electrical conductivity and the total dissolved solid of the groundwater was obtained as 390 μS/cm and 245 mg/cm3 respectively. These values are within the acceptable limit set by the Standard Organization of Nigeria (SON) for drinking water. The result of the vertical electrical sounding interpreted using the computer iterative modeling revealed the presence of four to five geoelectric layers which showed a close correlation with result from the lithology and downhole logging. Results further showed that the resistivity of the subsurface aquifer ranged between 1584 and 5420 Ωm while the aquifer depths varied between 27.8 and 39.3 m. Groundwater development of the area is suggested using the depth and resistivity maps provided in this study. 相似文献
3.
B. Suski F. Ladner L. Baron F.-D. Vuataz F. Philippossian K. Holliger 《Hydrogeology Journal》2008,16(7):1319-1328
A geophysical and geochemical study has been conducted in a fractured carbonate aquifer located at Combioula in the southwestern Swiss Alps with the objective to detect and characterize hydraulically active fractures along a 260-m-deep borehole. Hydrochemical analyses, borehole diameter, temperature and fluid electrical conductivity logging data were integrated in order to relate electrokinetic self-potential signals to groundwater flow inside the fracture network. The results show a generally good, albeit locally variable correlation of variations of the self-potential signals with variations in temperature, fluid electrical conductivity and borehole diameter. Together with the hydrochemical evidence, which was found to be critical for the interpretation of the self-potential data, these measurements not only made it possible to detect the hydraulically active fractures but also to characterize them as zones of fluid gain or fluid loss. The results complement the available information from the corresponding litholog and illustrate the potential of electrokinetic self-potential signals in conjunction with temperature, fluid electrical conductivity and hydrochemical analyses for the characterization of fractured aquifers, and thus may offer a perspective for an effective quantitative characterization of this increasingly important class of aquifers and geothermal reservoirs. 相似文献
4.
为准确获取水文地质参数,进而为矿井防治水、矿井涌水量计算以及地下水评价等提供可靠的参数,以煤田地质勘探中实测的人工井液电阻率测井曲线为依据,结合岩心精细描述、抽水试验、常规地球物理测井等技术获得的资料进行综合分析。研究表明:人工井液电阻率测井技术在煤田水文地质勘探中不仅可以准确划分含隔水层的性质,确定其位置,分析含水层之间的补给关系,检查钻孔止水效果,计算各含水层钻孔截面流量,亦可研究地下水流体特征,评价地下水水质参数以及监测生产矿井导水裂隙带高度。因此,人工井液电阻率测井能够提高煤田水文地质勘探成果利用率,实现地质勘探信息的最大化利用,从而更好地为矿井设计、建设及矿井生产服务,保障矿井安全。 相似文献
5.
A combination of electrical imaging carried out across a tidal creek and borehole electrical tomography between strings of
electrodes installed in bores adjacent to the creek is used to establish the shape of the hyporheic zone beneath a tidal creek
in a sand aquifer. The interpretations provided by the data inversions are checked against fluid electrical conductivity (EC)
samples collected from bundled piezometers installed in the creek banks and from bulk EC measurements made using induction
logs in bores on the creek banks. Extensive seepage into the base of the creek is identified from the electrical image and
verified by independent measurements of hydraulic head and fluid EC. The Effective Medium Theory is used to derive values
of fluid EC from bulk resistivity measurements obtained from the inversion process. The data show an extensive zone of mixing
between seawater and rainwater recharge into the aquifer, with the shape of the hyporheic zone strongly influenced by regional
groundwater discharge and the presence of a thin layer of cemented sands at a depth of 10 m. The combined interpretation demonstrates
the importance of borehole control in the interpretation of electrical images measured from the surface over complex EC distributions.
Electronic Publication 相似文献
6.
7.
Confined groundwater near the rockhead in igneous rocks in the Mid-Levels area, Hong Kong, China 总被引：1，自引：0，他引：1
It is customary in Hong Kong to assume that the hydraulic conductivity of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered. Such a hydraulic conductivity pattern can only lead to an unconfined aquifer. This paper presents a case study in the regions in and around the Mid-Levels area in Hong Kong regarding a possible relatively high hydraulic conductivity (K) zone and confined groundwater along the rockhead. The Mid-Levels area is located at the lower part of the north-facing slopes of Victoria Peak on Hong Kong Island and is prone to landslides. Although this site has a long history of geotechnical studies because of extensive urban development along the coast and public concern on slope stability, hydrogeology of the site remains poorly understood. This paper reexamined the hydraulic conductivity data in 7 boreholes conducted in the 1970s and found that 4 of them indicate an increase in K at the rockhead. Groundwater conditions revealed by tunnel construction at the coast suggest that K close to the rockhead is about 10 times greater than above rockhead. A careful analysis of storm response of a piezometer group with tips in different depths indicates that there was an upward flow from the bedrock to the colluvium. A field study of two overflow standpipes conducted by the authors showed that the water level can be 0.64 and 3.73 m above the ground surface, which illustrates that the deep groundwater is significantly artesian. A search of the archived site investigation reports from the government and private companies has led to an identification of about 24 sites with overflow boreholes, which suggests that overflow phenomenon is quite common in the study area. The paper then concludes that in the study area there is a relatively high K zone along the rockhead and the groundwater in the zone is confined. It is recommended that geotechnical engineers should carry out a more careful field study on an overflow borehole because such a borehole indicates a confined groundwater condition important for slope stability study and foundation design. 相似文献
8.
岩溶水勘察中测井资料的综合应用 总被引：1，自引：0，他引：1
郭崇光 《华北地质矿产杂志》1994,9(3):317-322
本文主要以山西晋城、离（石）柳（林）、阳曲等碳酸盐地层供水勘探中的实际资料为例，论述各种水文测井方法解释含水层的局限性和如何综合利用测井资料，正确确定含水层、隔水层位置及补给关系。实践表明，井温和井液电阻率测井，方法简便易行，能直接反映地下水的一些特征，必须测量；声幅曲线能直接反映裂隙层位，应尽可能施测。 相似文献
9.
10.
The Chalk aquifer of Champagne (France) baseline geochemistry has been determined using a solid solution approach for the modelling of calcite dissolution. The water–rock interactions are modelled by the speciation code CHESS from field data and Ca, Mg and Sr aqueous concentrations in groundwater. The stoichiometries of solid solutions are defined in each stratigraphic unit of the Chalk aquifer from bulk geochemistry and Chalk mineralogy of samples taken from boreholes. The initial mineralisation of water at the bottom of the unsaturated zone and the characterisation of the theoretical evolution of groundwater chemistry along the flow lines associated with incongruent calcite dissolution are calculated from this approach. 相似文献
11.
Moroof O. Oloruntola Olateju O. Bayewu Ganiyu O. Mosuro Adetayo F. Folorunso Sefiu O. Ibikunle 《Arabian Journal of Geosciences》2017,10(5):110
A combination of vertical electrical soundings (VES), 2D electrical resistivity imaging (ERI) surveys and borehole logs were conducted at Magodo, Government Reserve Area (GRA) Phase 1, Isheri, Southwestern Nigeria, with the aim of delineating the different aquifers present and assessing the groundwater safety in the area. The Schlumberger electrode array was adopted for the VES and dipole-dipole array was used for the 2D imaging. The maximum current electrode spread (AB) was 800 m and the 2D traverse range between 280 and 350 m in the east-west direction. The thickness of impermeable layer overlying the confined aquifer was used for the vulnerability ratings of the study area. Five lithological units were delineated: the topsoil, clayey sand, unconsolidated sand which is the first aquifer, a clay stratum and the sand layer that constitutes the confined aquifer horizon. The topsoil thickness varies from 0.6 to 2.6 m, while its resistivity values vary between 55.4 and 510.6 Ω/m. The clayey sand layers have resistivity values ranging from 104.2 to 143.9 Ω/m with thickness varying between 0.6 and 14.7 m. The resistivity values of the upper sandy layer range from 120.7 to 2195.2 Ω/m and thickness varies from 3.3 to 94.0 m. The resistivity of the clay layer varies from 11.3 to 96.1 Ω/m and the thickness ranges from 29.6 to 76.1 m. The resistivity value of the confined aquifer ranges between 223 and 1197.4 Ω/m. The longitudinal conductance (0.0017–0.02 mhos) assessment of the topsoil shows that the topsoil within the study area has poor overburden protective capacity, and the compacted impermeable clay layer shows that the underlying confined aquifer is well protected from contamination and can be utilized as a source of portable groundwater in the study area. This study therefore enabled the delineation of shallow aquifers, the variation of their thicknesses and presented a basis for safety assessment of groundwater potential zones in the study area. 相似文献
12.
In addition to spatial distribution of groundwater-flow parameters, aquifer properties of location and shape are also significant for assessing groundwater resources because they strongly affect water flow. We present a selection of geologic data suitable for aquifer analysis, a mathematical method of processing them, and a combination of several maps produced by it. The data used in the analysis are typically obtained by borehole investigation. Our targets are the areas underlain by geologic bodies with different ages and lithologies; the spatial correlation structures of geologic data over the areas tend to change locally. The processing method should be a versatile one that is applicable to areas where geostatistical stationarity is not satisfied. The aquifer analysis consistent with that requirement consists of two steps: the first is the transformation of screen locations, locations of sand and gravel layers, and resistivity by electric logging into indicator values, and the second is three-dimensional interpolation of these using the optimization principle method to produce three kinds of distribution models. A stochastic simulation is also used for modeling the resistivity distribution. The three distribution models are integrated to generate a value for evaluating the possibility of aquifer existence. A case study of an alluvial coastal plain, situated in southwest Japan, describes an aquifer model that contains three permeable layers. Each layer has about 10-m thickness and is lens shaped. To confirm the validity of the model, we have drilled two wells that reached one of the middle and bottom permeable layers, observing the water level change. Low correlation of the temporal changes of levels between the wells indicates that the two layers are hydrologically independent of each other. Additionally, groundwater-flow patterns have been estimated by transforming the simulation model parameter into hydraulic conductivity through a simple function and using a finite difference method for flow analysis. The procedure proposed by this study can be applied to other areas by changing the weights assigned to each geologic and geotechnical factor in the generation of the coefficient for aquifer existence, considering the reliability of each factor and hydrologic properties of study area. 相似文献
13.
Stream-aquifer interactions in the Maules Creek catchment, Namoi Valley, New South Wales, Australia 总被引：1，自引：1，他引：0
The interaction between surface-water streams and groundwater in the Maules Creek catchment of northern New South Wales, Australia has been investigated using a wide range of techniques. Zones of groundwater discharge were mapped by measuring the temperature and fluid electrical-conductivity distribution in bores and surface water. Zones where surface water appears to be recharging the aquifer were investigated by measuring the vertical head gradient between the stream and adjacent bores and by estimates of the decreasing surface flow. Geological heterogeneity appears to be the most significant factor in controlling exchange. Lithological information was assembled using geophysical logging of existing bores, supplemented by the results of electrical resistivity imaging. A preliminary water balance was assembled from the available State records of groundwater abstraction for irrigation, rainfall, evapotranspiration and flow gauging in Maules Creek and the adjacent Namoi River. The analysis has demonstrated the complexity of these coupled systems and gives an indication of the most efficient techniques to be deployed in the field to investigate these complex but important systems. 相似文献
14.
Communities and water utilities are increasingly being forced to implement more hydrogeologically complex alternative water supply and storage options to meet increasing freshwater demands. The performance of managed aquifer recharge projects, including aquifer storage and recovery, is controlled by the movement and mixing of stored freshwater and native groundwater, and fluid–rock interactions, which, in turn, are strongly influenced by aquifer heterogeneity. Advanced borehole geophysical logging techniques developed for the oil and gas industry such as neutron-gamma ray spectroscopy, microresistivity imaging, and nuclear magnetic resonance, can provide hitherto unavailable fine-scale data on porosity (total and effective), hydraulic conductivity, salinity, and the mineralogical composition of aquifers. Data on aquifer heterogeneity obtained from advanced borehole geophysics logs, combined with information on larger-scale aquifer hydraulics obtained from pumping tests, have the potential for improving aquifer characterization and modeling needed for feasibility assessments and the design and optimization of the operation of managed aquifer recharge systems. 相似文献
15.
A small-scale hydrogeological study was conducted in a fractured carbonate-rock aquifer located in a quarry to relate groundwater flow to the fracture network. The field study in the St-Eustache quarry, which integrates structural surveys, well logging and hydraulic tests, showed that the most important features that affect groundwater flow in the sedimentary aquifer are high hydraulic conductivity horizontal bedding planes. Vertical fractures are abundant in the quarry and throughout the region, but they have a minor effect on groundwater flow. To have a significant impact on the flow regime and lead to vertical groundwater flow, the permeability of all vertical joints need to be enhanced compared to what was generally observed at the site. Such an increase in permeability could potentially occur where dissolution and fracturing is more intense or at stress release locations such as near the surface in the quarry. 相似文献
16.
A. P. Butler S. A. Mathias A. J. Gallagher D. W. Peach A. T. Williams 《Hydrogeology Journal》2009,17(8):1849-1858
An integrated set of different measurements has been used to study the behavior of groundwater in an observation well in a fractured rock formation, the UK Chalk, under pumped and ambient conditions. Under pumped conditions, the response of the open borehole was relatively straightforward with flow mainly concentrated along four discrete flow horizons. Furthermore, excellent correspondence was observed between the three methods of borehole flow velocity measurement: impeller flowmeter, heat-pulse flowmeter and dilution testing. Under ambient conditions, the system appeared more complicated. Specifically, in the upper half of the borehole, the impeller flowmeter exhibited substantial downward flow and the heat-pulse flowmeter exhibited almost negligible upward flow, whilst dilution testing indicated significant dilution. It was concluded that this was due to cross-flow occurring over the upper 29 m. Analysis of drawdown data, recovery data and a Drost analysis of the ambient cross-flow data yielded aquifer transmissivity estimates of 2,049, 2,928 and > 4,388 m2/day respectively. The discrepancy between the drawdown and recovery estimates was attributed to non-linear head-losses associated with turbulence and inertial effects. The difference between the pumping test and Drost results was explained by the flow during the pumping test bypassing this aforementioned 29 m region of rock. 相似文献
17.
This paper presents the combination of two complementary methods, magnetic and joint inversion of resistivity/TEM data, as
an effective approach to characterize groundwater reservoirs. Twenty stations of transient electromagnetic (TEM) and vertical
electrical soundings (VES) were measured and interpreted using a joint inversion technique to evaluate the subsurface low
resistivity zones connected to the groundwater reservoir. A complementary survey including 871 land magnetic stations was
carried out at the same area to detect the upper surface of the basaltic sheet, which represents the bottom of the Miocene
aquifer in the study area. The geological log from one borehole drilled in the zone was used to partially calibrate the calculated
models. The results revealed that the study area consists of five different geological units with ages ranging from Paleogene
(Oligocene) to Quaternary. The methodology provides good results at a very low cost when compared with drilling boreholes. 相似文献
18.
A hydrogeological study was conducted in northwestern New Brunswick, Canada, to improve the predictability of fracture-dominated groundwater flow within folded bedrock composed of fine-grained turbidites. Borehole televiewer logging and outcrop mapping, integrated with hydraulic packer tests revealed enhanced hydraulic conductivity associated with northeasterly striking bedding-plane fractures formed during folding and flexural slip. These fractures impart azimuthal anisotropy to the aquifer because of moderately dipping fold limbs. High-angle fractures form a well-developed non-stratabound network, comprising two open fracture sets striking NNE parallel to the current direction of principal stress, and WNW parallel to the direction of principal stress that dominated during the Acadian orogeny. The subset of fractures showing significant oxidation, deemed most important to the groundwater flow system, is dominated by bedding-plane and high-angle fractures striking near-parallel to the maximum principal stress direction, resulting in extensional opening and enhanced hydraulic conductivities. An equivalent porous media model, incorporating anisotropy and varying hydraulic conductivity with depth, indicates that horizontal flow dominates the aquifer with relatively minor exchange between different model layers. These findings have implications for understanding flow directions in the Black Brook Watershed and elsewhere in the Matapédia Basin where fractures formed under similar stress conditions. 相似文献
19.
The groundwater flow regime at great depth within the Molasse Basin (SW Germany) was studied. Data relevant for a flow model at 600–1,600 m depth are sparse in the western part of the basin. However, temperature measurements are available covering much of the area at a wide range of depths. Therefore, a thermal 3D steady-state model was set up with the aim of comparing modeled with observed subsurface temperatures. Stratigraphic information from many boreholes was also available, but only a few values of rock thermal conductivity and heat-production rate could be obtained. Some strong thermal residual anomalies were identified with respect to the purely conductive model, especially along fault zones, and within stratigraphic layers with high hydraulic conductivity. These anomalies can be explained by various advective heat-transport mechanisms, yet most explanations can be eliminated. The most plausible constellation explaining the major positive thermal anomalies of 10 Kelvin and more is a fault zone of E–W strike, intersected by an aquifer with flow parallel to the fault zone. This concept was investigated by using a simplified type model. In spite of some shortcomings, the method presented here can be used to identify temperature anomalies, and to identify possible explanations. 相似文献
20.
含水层参数对于定性分析区域地下水资源评价、数值模拟及预报、开发利用与保护及科学管理具有重要意义,而江汉平原水文地质参数求解的研究却相对较少.2015年江汉平原1:50 000水文地质调查项目完成杨林尾图幅与陆溪口图幅,选择杨林尾图幅和陆溪口图幅中的4个代表性钻孔,分别做了3组抽水试验和一组压水试验.对抽水数据使用Dupuit公式法结合抽水稳定阶段数据求解含水层参数,同时利用Aquifer Test软件中Theis标准曲线法、直线图解法对抽水试验中非稳定条件下抽水数据对含水层参数求解,得到孔隙水含水层渗透系数及弹性给水度;利用压水试验工程规范求解基岩裂隙含水层的渗透系数.探讨了利用非稳定抽水试验条件下求解含水层参数方法的可行性及该方法的优势.计算结果表明:杨林尾镇浅层(20.2~64.55 m)含水层渗透系数为0.075 m/d,弹性给水度为5.8×10-2;深层(138~160 m)含水层渗透系数为9.89 m/d,弹性给水度为2.3×10-5;陆溪口镇浅层(19.4~36.4 m)含水层渗透系数1.26 m/d,弹性给水度为1.1×10-1;基岩渗透系数为0.012 m/d.通过结果对比分析发现对于单孔非稳定抽水试验,对前期水位降深数据筛选分析,同样可以利用非稳定井流理论反演含水层参数,结果比较可靠. 相似文献