Statistical and geostatistical investigations into the effects of the Gabcikovo hydropower plant on the groundwater resources of northwest Hungary / Analyses statistiques et géostatistiques des effets de la centrale hydroélectrique de Gabcikovo sur les ressources en eaux souterraines du Nord-Ouest de la Hongrie     

《水文科学杂志》2013,58(4)

Abstract

Abstract The construction of the Gabcikovo hydropower plant and the diversion of the Danube River over 25 km into an artificial channel in 1992 influenced the groundwater regime of the region considerably. Statistical and geostatistical methods are used to quantify changes of different groundwater characteristics on the Hungarian side of the river based on observations in the time period 1960–2000. External drift kriging was used to interpolate groundwater levels and the other related variables. While mean groundwater levels did not change appreciably, there are significant changes in the variability. Standard deviations of the groundwater levels and the amplitude of the annual cycle decreased near the old river bed of the Danube. The water-level fluctuations of the Danube have a decreased influence on the groundwater dynamics. Interrelationships between water levels in wells have also changed.  相似文献   

Numerical simulations on the relative importance of starbursts and AGN in ultraluminous infrared galaxies     

Kenji Bekki  Yasuhiro Shioya  Matthew Whiting 《Monthly notices of the Royal Astronomical Society》2006,371(2):805-820

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Interactions between groundwater and surface water in a virginia coastal plain watershed. 1. Hydrological flowpaths     

Keith N. Eshleman  John S. Pollard  Anne K. O'Brien 《水文研究》1994,8(5):389-410

A field study of surface water and groundwater interactions during baseflow and stormflow conditions was performed at the Reedy Creek watershed in the Virginia Coastal Plain. Three estimates of the average saturated hydraulic conductivity (K_s) of the unconfined aquifer were in reasonable agreement (ranging from 0.0033 to 0.010 cm/s), indicating that baseflow in the creek is entirely from the drainage of shallow groundwater from the relatively thin (1–6 m thick) unconfined aquifer. This relatively permeable surficial aquifer was found to be underlain by dark, olive grey, clay-silt and diatomaceous Miocene deposits of low permeability known as the Calvert Formation, which is believed to function as a confining bed in the area. A chemical hydrograph separation technique was used to resolve the contributions of [old] (pre-event) and [new] (event) water to stormflow. Results from a major rainstorm indicated that old water dominated the stormflow response of the watershed, although the new water contribution approached 40% at the hydrograph peak. Stormflow at Reedy Creek appears to result from saturation overland flow from variable source areas which include the stream channels and a significant part of the riparian wetland area. This response appears to be attributable to the transient dynamics of the shallow groundwater flow system and to the formation of localized groundwater mounds which raise the water-table to the wetland surface.  相似文献   

Dynamical limits on galactic winds, halo MACHOs and intergalactic globular clusters     

HongSheng Zhao † 《Monthly notices of the Royal Astronomical Society》2002,336(1):159-167

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A Chandra observation of the interacting pair of galaxies NGC 4485/4490     

T. P. Roberts  R. S. Warwick  M. J. Ward  S. S. Murray 《Monthly notices of the Royal Astronomical Society》2002,337(2):677-692

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Galaxy formation in pre-processed dark haloes     

H. J. Mo  Shude Mao 《Monthly notices of the Royal Astronomical Society》2004,353(3):829-840

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The co-evolution of the obscured quasar PKS 1549−79 and its host galaxy: evidence for a high accretion rate and warm outflow     

J. Holt  C. Tadhunter  R. Morganti  M. Bellamy  R. M. González Delgado  A. Tzioumis  K. J. Inskip 《Monthly notices of the Royal Astronomical Society》2006,370(4):1633-1650

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Geochronology, Geochemistry, Fluid Inclusion and C, O Isotope Compositions of Calcite Veins in the Paleogene of the Jiangling Basin, South China: Implications for Fluid Evolution and Brine Potash Mineralization     

YU Xiaocan  WANG Chunlian  LIU Chenglin  WANG Jiuyi  SHEN Lijian 《《地质学报》英文版》2023,97(2):513-525

Deep-seated potassium-rich brines were identified in the Jiangling Basin, South China. Although magmatic-hydrothermal sources have been proposed, the relationship between brine-type potash mineralization and volcanism remains unclear. In this study, U-Pb geochronology, geochemistry, fluid inclusion and C-O isotopic compositions of hydrothermal vein minerals in the Jiangling Basin are examined. Laser ablation U-Pb dating of calcite veins indicates that the ages are slightly younger than the formation age of the Balingshan basalt. Fluid inclusions in hydrothermal minerals show medium–low homogenization temperatures (160–220°C) and low salinities (0.14 to 4.9 wt% NaCl eqv.) and densities (0.882–0.944 g/cm3). The liquid compositions of fluid inclusions in calcite veins from sedimentary strata have higher contents of potassium, compared with those from basalt. The coupled negative δ13CPDB (?10.3‰ to ?8.0‰) and positive δ18OSMOW (17.4‰ to 20.7‰) values imply that calcite precipitation resulted from CO2 degassing of the basaltic magmatic fluids, as indicated by the gas composition of these inclusions in hydrothermal minerals. Rare earth element patterns indicate that water-rock interaction between hydrothermal fluids and sedimentary wall rocks contributed to the calcite precipitation in sedimentary strata. It is proposed that high-temperature water-rock interaction between magmatic fluids and sedimentary strata resulted in the potassium enrichment in fluids, interpreted as one of the sources of potassium-rich brines in the Jiangling Basin.  相似文献   

华北平原高氟地下水中稀土元素分布和分异特征     

刘海燕  刘茂涵  张卫民  孙占学  王振  吴通航  郭华明 《地学前缘》2022,29(3):129-144

高氟地下水是世界各国研究者广泛关注的重大环境问题。尽管对高氟地下水的化学特征、形成机理和扩散机制等已有不少研究,但其稀土元素(REE)的含量和分异特征以及这些特征能否反映高氟地下水的形成和分布尚不清楚,这在一定程度上限制了REE在高氟地下水中的运用。本研究以地下水氟离子异常严重地区——华北平原为研究区,沿地下水流向采集浅层和深层地下水样,研究分析了水中氟离子和REE的地球化学特征。浓度分析结果表明地下水氟离子浓度介于0.28 mg/L和9.33 mg/L之间,其中55%超出我国饮用水标准规定值1.0 mg/L;PHREEQC计算结果反映地下水中氟以NaF、CaF⁺、MgF⁺和自由态F^-形式存在,其中自由态F^-含量占主导(85.42%99.39%);高氟地下水主要分布于中部冲积湖积平原以及东部冲积海积平原,60%高氟地下水样分布在180 m深度以下;水化学图件分析结果指示浅层高氟地下水的形成主要受蒸发浓缩作用的控制,而深层高氟地下水是水岩相互作用下的矿物溶解和离子竞争吸附共同作用的结果。研究区地下水REE含量处于pmol/L至nmol/L级别,PHREEQC模拟计算结果表明REE主要以碳酸络合物( {\mathrm{REECO}}_3^{+}和$REE(CO_{3})_{2}^{-})$的形式存在,与氟离子络合的稀土元素(REEF²⁺和 {\mathrm{REEF}}_2^{+})占01.18%;上陆壳(UCC)标准化结果显示,所有地下水均呈重REE(HREE)和中REE(MREE)相对于轻REE(LREE)富集的模式,且具有显著Ce负异常(0.11* = Ce_UCC/(La_UCC×Pr_UCC)^0.5<2.29)特性;地下水富HREE主要归因于HREE比LREE优先与碳酸根络合,并且形成更加稳定的碳酸络合物。沿地下水流向,深层地下水中总REE含量与地下水中氟浓度均呈现不断上升的变化趋势,同时高氟地下水比低氟地下水更易富集重稀土元素,说明稀土元素对深层含水层富氟行为具有一定的指示作用。  相似文献   

江陵凹陷新生代玄武岩水-岩反应模拟及其对富钾卤水成因的指示          下载免费PDF全文

王春连  刘成林  余小灿  王九一  李瑞琴  段晓旭  刘思晗  游超  周博文 《地球科学》2022,47(1):94-109

关于江陵凹陷富钾卤水的物质来源和成因机理仍未查明. 对凹陷新生代玄武岩开展矿物学、岩石学、地球化学研究以及水-岩反应模拟实验,重点研究时间、温度、流体成分等对水-岩反应的影响. 结果表明,卤水具有高锂低镁的特征,说明其在成因上受到火山活动的影响;研究区岩浆发生不同程度的分异,玄武岩蚀变作用强烈,表明地下热液的交代作用强烈,玄武岩通过水-岩反应为富钾卤水矿提供了物质来源;温度是流体对元素的淋滤能力的主要控制因素,高盐度流体是各成矿元素主要的迁移载体,水-岩反应是卤水形成的重要过程.   相似文献