共查询到19条相似文献，搜索用时 78 毫秒
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利用核磁共振（ＮｕｃｌｅａｒＭａｇｎｅｔｉｃＲｅｓｏｎａｎｃｅ缩写为ＮＭＲ）技术探查地下水仅有二十多年的历史,文中简要介绍了ＮＭＲ找水方法的发展状况,原理和方法特点,重点介绍了中国地质大学（武汉）利用ＮＭＲ找水方法在中国一些地区找水取得的成效,最后指出了ＮＭＲ找水方法的发展趋势。 相似文献
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利用核磁共振方法探查岩溶水 总被引：19，自引：4，他引：15
核磁共振（ＮＭＲ）找水方法是目前唯一直接找水的物探新方法,该方法可以探查各种类型的地下水。本文仅论述了在岩溶发育区常规电阻率方法找水时遇到的地质干扰。ＮＭＲ找水方法的原理,仪器的组成,并以实例说明了ＮＭＲ找水方法探查岩溶水的效果。 相似文献
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乌蒙山区水资源严重缺乏,找水难度大.本文综合分析、研究了当前山区物探找水方法的现状,总结各物探找水方法的优点、缺点;以经济、高效为原则,优选出高密度电阻率成像、密集型激电测深和视电阻率测井等3种综合物探方法组合,开展探采结合井位确定;从定性─定量─验证等三层次,提出有效地地球物理找水方法技术组合:采用高密度电阻率法定性分析地层,密集型激电测深工作定量分析含水地层,视电阻率测井资料进行验证.利用反射系数法、衰减度等新技术进行资料综合处理与解释,准确地对探采结合井进行定位.高密度电阻率法和密集型激电测深得到的含水层与钻孔实际深度误差均小于5%,证明该方法组合能经济、快速、有效地确定基岩、含水性地层的深度;计算了高密度电法、激电测深得到的地层层位深度转换为真深度的校正系数,为该区物探找水勘查积累了经验,为该区域地下水勘查起到一定的示范作用. 相似文献
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核磁共振测深方法的新进展 总被引：4，自引：1，他引：3
核磁共振测深(MRS)方法是目前唯一直接探查地下水的新方法.本文概要介绍了参加第二届核磁共振测深(MRS)国际学术研讨会的主要收获.阐述了核磁共振找水仪的研制和进展以及扩大了MRS方法的应用领域方面的情况.在应用MRS方法探测地下水取得很大成效的此基础上,我们率先用MRS方法进行了三峡滑坡监测和秦始皇陵考古工作,又取得了新成果. 相似文献
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地面磁共振测深是目前唯一直接探测地下水的地球物理方法,具有灵敏、高效、无损等优点,在地下水探测中具有独特优势.玄武岩含水层常富含锶、偏硅酸等矿物质,为潜在矿泉水水源地,但其内部磁性矿物的存在限制了常规地面磁共振测深方法的应用.针对这一难题,笔者分别采用FID和CPMG两种脉冲序列开展了地面磁共振测深实验,结合钻孔资料验证了该方法的可行性.通过对两种脉冲序列反演弛豫时间和含水量的对比研究,发现FID脉冲序列反演获得平均横向弛豫时间T2*受非均匀磁场主导,并不能反映含水层孔隙度大小,但反演含水量结果优于CPMG脉冲序列;CPMG脉冲序列可以反演横向弛豫时间T2,但易导致含水量低估.因此,笔者认为在磁性含水层地面磁共振测深中,可采用FID脉冲序列反演含水量并结合CPMG脉冲序列反演T2,实现对含水层富水性和孔隙度大小进行探测. 相似文献
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近20多年来,用核磁共振(Nuclear Magnetic Resonance,NMR)方法形成的一种直接非侵害性的探测地下水的地球物理新技术,与传统的地球物理探测地下水的方法相比具有高分辨力、高效率、信息量丰富和解的唯一性等优点,是一种很有发展前景的找水方法技术.我国的水资源短缺,对地下水资源的勘探、开发与利用十分重视,已将核磁共振找水技术研究列入国家十一五科技支撑计划.本文在广泛收集迄今为止的国内外大量资料的基础上,并根据作者近年来有关核磁共振找水技术的研究经历,综述了核磁共振找水技术的发展历史、现状和发展趋势,以推进我国核磁共振找水技术的发展. 相似文献
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为准确确定露天煤矿地下水分布与类型,根据不同赋存条件电磁差异,基于磁场强度与电阻率参数进行异常划分与类型判别。以新疆某露天煤矿为例,采用高精度磁法通过磁异常强度确定烧变岩边界,并采用高密度电法和瞬变电磁法通过电阻率圈定低阻异常区,结合异常响应差异分别推断地下水分布范围与赋存类型。地面钻探验证探测成果的准确性。结果表明:露天煤矿烧变岩水与砂岩裂隙水电磁响应差异明显,基于磁场强度与电阻率的双参数综合电磁法能准确圈定其分布范围,并判别其赋存类型。 相似文献
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The role of bedrock groundwater in rainfall–runoff processes is poorly understood. Hydrometric, tracer and subsurface water potential observations were conducted to study the role of bedrock groundwater and subsurface flow in the rainfall–runoff process in a small headwater catchment in Shiranui, Kumamoto prefecture, south‐west Japan. The catchment bedrock consists of a strongly weathered, fractured andesite layer and a relatively fresh continuous layer. Major chemical constituents and stable isotopic ratios of δ18O and δD were analysed for spring water, rainwater, soil water and bedrock groundwater. Temporal and spatial variation in SiO2 showed that stream flow under the base flow condition was maintained by bedrock groundwater. Time series of three components of the rainstorm hydrograph (rainwater, soil water and bedrock groundwater) separated by end member mixing analysis showed that each component fluctuated during rainstorm, and their patterns and magnitudes differed between events. During a typical mid‐magnitude storm event, a delayed secondary runoff peak with 1·0 l s−1 was caused by increase in the bedrock groundwater component, whereas during a large rainstorm event the bedrock groundwater component increased to ≈ 2·5 l s−1. This research shows that the contribution of bedrock groundwater and soil water depends strongly on the location of the groundwater table, i.e. whether or not it rises above the soil–bedrock interface. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Contributions of bedrock groundwater to the upscaling of storm‐runoff generation processes in weathered granitic headwater catchments 
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下载免费PDF全文 We examined the contributions of bedrock groundwater to the upscaling of storm‐runoff generation processes in weathered granitic headwater catchments by conducting detailed hydrochemical observations in five catchments that ranged from zero to second order. End‐member mixing analysis (EMMA) was performed to identify the geographical sources of stream water. Throughfall, hillslope groundwater, shallow bedrock groundwater, and deep bedrock groundwater were identified as end members. The contribution of each end member to storm runoff differed among the catchments because of the differing quantities of riparian groundwater, which was recharged by the bedrock groundwater prior to rainfall events. Among the five catchments, the contribution of throughfall was highest during both baseflow and storm flow in a zero‐order catchment with little contribution from the bedrock groundwater to the riparian reservoir. In zero‐order catchments with some contribution from bedrock groundwater, stream water was dominated by shallow bedrock groundwater during baseflow, but it was significantly influenced by hillslope groundwater during storms. In the first‐order catchment, stream water was dominated by shallow bedrock groundwater during storms as well as baseflow periods. In the second‐order catchment, deeper bedrock groundwater than that found in the zero‐order and first‐order catchments contributed to stream water in all periods, except during large storm events. These results suggest that bedrock groundwater influences the upscaling of storm‐runoff generation processes by affecting the linkages of geomorphic units such as hillslopes, riparian zones, and stream channels. Our results highlight the need for a three‐dimensional approach that considers bedrock groundwater flow when studying the upscaling of storm‐runoff generation processes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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The quantitative evaluation of the effects of bedrock groundwater discharge on spatial variability of stream dissolved organic carbon (DOC), dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorous (DIP) concentrations has still been insufficient. We examined the relationships between stream DOC, DIN and DIP concentrations and bedrock groundwater contribution to stream water in forest headwater catchments in warm-humid climate zones. We sampled stream water and bedrock springs at multiple points in September and December 2013 in a 5 km2 forest headwater catchment in Japan and sampled groundwater in soil layer in small hillslopes. We assumed that stream water consisted of four end members, groundwater in soil layer and three types of bedrock groundwater, and calculated the contributions of each end member to stream water from mineral-derived solute concentrations. DOC, DIN and DIP concentrations in stream water were compared with the calculated bedrock groundwater contribution. The bedrock groundwater contribution had significant negative linear correlation with stream DOC concentration, no significant correlation with stream DIN concentration, and significant positive linear correlation with stream DIP concentration. These results highlighted the importance of bedrock groundwater discharge in establishing stream DOC and DIP concentrations. In addition, stream DOC and DIP concentrations were higher and lower, respectively, than those expected from end member mixing of groundwater in soil layer and bedrock springs. Spatial heterogeneity of DOC and DIP concentrations in groundwater and/or in-stream DOC production and DIP uptake were the probable reasons for these discrepancies. Our results indicate that the relationships between spatial variability of stream DOC, DIN and DIP concentrations and bedrock groundwater contribution are useful for comparing the processes that affect stream DOC, DIN and DIP concentrations among catchments beyond the spatial heterogeneity of hydrological and biogeochemical processes within a catchment. 相似文献
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This study presents an approach for delineating groundwater basins and estimating rates of recharge to fractured crystalline bedrock. It entailed the use of completion report data (boring logs) from 2500 domestic wells in bedrock from the Coventry Quadrangle, which is located in northeastern Connecticut and characterized by metamorphic gneiss and schist. Completion report data were digitized and imported into ArcGIS® for data analysis. The data were processed to delineate groundwater drainage basins for the fractured rock based on flow conditions and to estimate groundwater recharge to the bedrock. Results indicate that drainage basins derived from surface topography, in general, may not correspond with bedrock drainage basins due to scale. Estimates of recharge to the bedrock for the study area indicate that only a small fraction of the precipitation or the amount of water that enters the overburden recharges the rock. The approach presented here can be a useful method for water resource‐related assessments that involve fractured rock aquifers. 相似文献
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W. Payton Gardner Kelsey Jensco Zachary H. Hoylman Robert Livesay Marco P. Maneta 《水文研究》2020,34(15):3311-3330
Here we use Richards Equation models of variably saturated soil and bedrock groundwater flow to investigate first-order patterns of the coupling between soil and bedrock flow systems. We utilize a Monte Carlo sensitivity analysis to identify important hillslope parameters controlling bedrock recharge and then model the transient response of bedrock and soil flow to seasonal precipitation. Our results suggest that hillslopes can be divided into three conceptual zones of groundwater interaction, (a) the zone of lateral unsaturated soil moisture accumulation (upper portion of hillslope), (b) the zone of soil saturation and bedrock recharge (middle of hillslope) and (c) the zone of saturated-soil lateral flow and bedrock groundwater exfiltration (bottom of hillslope). Zones of groundwater interaction expand upslope during periods of precipitation and drain downslope during dry periods. The amount of water partitioned to the bedrock groundwater system a can be predicted by the ratio of bedrock to soil saturated hydraulic conductivity across a variety of hillslope configurations. Our modelled processes are qualitatively consistent with observations of shallow subsurface saturation and groundwater fluctuation on hillslopes studied in our two experimental watersheds and support a conceptual model of tightly coupled shallow and deep subsurface circulation where groundwater recharge and discharge continuously stores and releases water from longer residence time storage. 相似文献
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Miles P. Wilson Fred Worrall Sarah A. Clancy Chris J. Ottley Alwyn Hart Richard J. Davies 《水文研究》2020,34(15):3271-3294
An environmental concern with hydraulic fracturing for shale gas is the risk of groundwater and surface water contamination. Assessing this risk partly involves the identification and understanding of groundwater–surface water interactions because potentially contaminating fluids could move from one water body to the other along hydraulic pathways. In this study, we use water quality data from a prospective shale gas basin to determine: if surface water sampling could identify groundwater compartmentalisation by low-permeability faults; and if surface waters interact with groundwater in underlying bedrock formations, thereby indicating hydraulic pathways. Variance analysis showed that bedrock geology was a significant factor influencing surface water quality, indicating regional-scale groundwater–surface water interactions despite the presence of an overlying region-wide layer of superficial deposits averaging 30–40 m thickness. We propose that surface waters interact with a weathered bedrock layer through the complex distribution of glaciofluvial sands and gravels. Principal component analysis showed that surface water compositions were constrained within groundwater end-member compositions. Surface water quality data showed no relationship with groundwater compartmentalisation known to be caused by a major basin fault. Therefore, there was no chemical evidence to suggest that deeper groundwater in this particular area of the prospective basin was reaching the surface in response to compartmentalisation. Consequently, in this case compartmentalisation does not appear to increase the risk of fracking-related contaminants reaching surface waters, although this may differ under different hydrogeological scenarios. 相似文献
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Ground-penetrating radar is a technique which offers a new way of viewing shallow soil and rock conditions. The need to better understanding overburden conditions for activities such as geochemical sampling, geotechnical investigations, and placer exploration, as well as the factors controlling groundwater flow, has generated an increasing demand for techniques which can image the subsurface with higher resolution than previously possible. The areas of application for ground-penetrating radar are diverse. The method has been used successfully to map ice thickness, water depth in lakes, bedrock depth, soil stratigraphy, and water table depth. It is also used to delineate rock fabric, detect voids and identify karst features. The effective application of the radar for the high-resolution definition of soil stratigraphy and fractures in bedrock is highlighted. The basic principles and practices involved in acquiring high quality radar data in the field are illustrated by selected case histories. One example demonstrates how radar has been used to map the bedrock and delineate soil horizons to a depth of more than 20 m. Two case histories show how radar has been used to map fractures and changes of rock type to 40 m range from inside a mine. Another case history demonstrates how radar has also been used to detect and map the extent of groundwater contamination. The corroboration of the radar results by borehole investigations demonstrates the power and utility of the high-resolution radar method as an aid for interpolation and extrapolation of the information obtained with conventional coring programmes. With the advent of new instrumentation and field procedures, the routine application of the radar method is becoming economically viable and the method will see expanded use in the future. 相似文献