Spatial patterns of groundwater‐lake exchange – implications for acid neutralization processes in an acid mine lake     

Christiane Neumann  Julia Beer  Christian Blodau  Stefan Peiffer  Jan H. Fleckenstein 《水文研究》2013,27(22):3240-3253

Exchange of groundwater and lake water with typically quite different chemical composition is an important driver for biogeochemical processes at the groundwater‐lake interface, which can affect the water quality of lakes. This is of particular relevance in mine lakes where anoxic and slightly acidic groundwater mixes with oxic and acidic lake water (pH < 3). To identify links between groundwater‐lake exchange rates and acid neutralization processes in the sediments, exchange rates were quantified and related to pore‐water pH, sulfate and iron concentrations as well as sulfate reduction rates within the sediment. Seepage rates measured with seepage meters (?2.5 to 5.8 L m^‐2 d^‐1) were in reasonable agreement with rates inverted from modeled chloride profiles (?1.8 to 8.1 L m^‐2 d^‐1). Large‐scale exchange patterns were defined by the (hydro)geologic setting but superimposed by smaller scale variations caused by variability in sediment texture. Sites characterized by groundwater upwelling (flow into the lake) and sites where flow alternated between upwelling and downwelling were identified. Observed chloride profiles at the alternating sites reflected the transient flow regime. Seepage direction, as well as seepage rate, were found to influence pH, sulfate and iron profiles and the associated sulfate reduction rates. Under alternating conditions proton‐consuming processes, for example, sulfate reduction, were slowed. In the uppermost layer of the sediment (max. 5 cm), sulfate reduction rates were significantly higher at upwelling (>330 nmol g^‐1 d^‐1) compared to alternating sites (<220 nmol g^‐1 d^‐1). Although differences in sulfate reduction rates could not be explained solely by different flux rates, they were clearly related to the prevailing groundwater‐lake exchange patterns and the associated pH conditions. Our findings strongly suggest that groundwater‐lake exchange has significant effects on the biogeochemical processes that are coupled to sulfate reduction such as acidity retention and precipitation of iron sulfides. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

滇西澜沧变质带中白云母的研究及其地质意义   总被引：7，自引：0，他引：7       下载免费PDF全文

赵靖 《岩石矿物学杂志》1993,(3)

本文以滇西澜沧变质带中最为广泛分布的造岩矿物——白云母为对象,详细研究和分析了其成分、多型类型及b_0值等,探讨了白云母的发育规律。研究结果表明,本带中绝大多数白云母为多硅白云母,且为3T+2M_1型,与蓝闪石共生的则以3T多硅白云母为主。此外,澜沧变质带经历了蓝闪石片岩亚相的高压变质作用,与古特提斯构造演化密切相关,并可与世界著名的高压带对比。  相似文献   

滇西澜沧变质带中白云母的研究及其地质意义          下载免费PDF全文

赵靖 《岩石矿物学杂志》1993,12(3):251-260

本文以滇西澜沧变质带中最为广泛分布的造岩矿物—白云母为对象，详细研究和 分析了其成分、多型类型及ba值等，探讨了白云母的发育规律。研究结果表明，本带中绝大多数白云母为多硅白云母，且为3T+2M,型，与蓝闪石共生的则以3T多硅白云母为主。此外，斓沧变质 带经历了蓝闪石片岩亚相的高压变质作用，与古特提斯构造演化密切相突，并可与世界著名的高 压带对比。  相似文献   

Modelling of earthquake rupturing as a stochastic process and estimation of its distribution function from earthquake observations     

Z.-M. Yin  G. Ranalli 《Geophysical Journal International》1995,123(3):838-848

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Characteristics of ionic components in precipitation in Kitakyushu City,Japan     

Yasuhiro Yamato  Takashi Yamada  Kozo Kido 《Journal of Atmospheric Chemistry》1993,17(4):325-337

Precipitation samples were collected by filtrating bulk sampler in Kitakyushu City, Japan, from January 1988 to December 1990. Volume weighted annual mean of pH was 4.93, but the pH distribution indicated that most probable value lay in the range pH 6.0–6.4. Volume weighted annual mean concentrations of major ionic components were as follows; SO ₄ ^2– : 84.2, NO ₃ ^– : 28.1, Cl^–: 86.3, NH ₄ ⁺ : 45.5, Ca²⁺: 63.3, Mg²⁺: 27.0, K⁺: 3.4, Na⁺: 69.0 µ eq l^–1. The highest concentrations of these ionic components were observed in winter and the lowest occurred in the rainy season. The ratio of ex-SO ₄ ^2– /NO ₃ ^– exhibited the lowest ratio in summer, and the highest ratio in winter. Good correlations were obtained between Cl^– and Na⁺, ex-SO ₄ ²⁺ and ex-Ca²⁺, NO ₃ ^– and ex-Ca²⁺, and NH ₄ ⁺ and ex-SO ₄ ^2– , respectively. However, no correlation between Cl^– and Na⁺ with Ca²⁺ was observed. The relationship of H⁺ with (ex-SO ₄ ^2– + NO ₃ ^– ) - (ex-Ca²⁺ + NH ₄ ⁺ ) indicated positive correlation.  相似文献   

云、雨水酸度和离子浓度与其微物理参数的关系   总被引：3，自引：0，他引：3       下载免费PDF全文

刘奇俊  丁国安  汤洁  房秀梅  吴凡  苏维瀚 《气象学报》1993,51(2):195-202

本文1987年5-6月和1989年5-6月庐山地区的实测资料,分析了云、雨水酸度和离子浓度与其微物理量间的关系。结果表明,云、雨滴大小、含水量、谱宽等微物理量的演变直接影响着其酸度和离子浓度。  相似文献   

The Holocene paleolimnology of Lake Sämbosjön,southwestern Sweden     

Gunnar Digerfeldt  Hannelore Håkansson 《Journal of Paleolimnology》1993,8(3):189-210

The Holocence paleolimnology of Lake Sämbosjön is described using geochemical and diatom analyses. The objective of this study is the reconstruction of major changes in trophic state and productivity, and to interpret the major causative processes. The accumulation of organic matter indicates a relatively high productivity in early Holocene, and the diatom analysis indicates a relatively high trophic state and pH. A succeeding decrease in productivity and trophic state and lowering in pH is recorded from about 8000 BP. If lake development had been primarily edaphically conditioned, viz. determined by nutrient supply from catchment soils, such a progressive oligotrophication would represent the common development of temperate lakes. Between about 6000 BP and 4000 BP Lake Sämbosjön was characterized by relatively stable productivity and pH. From about 4000 BP the analyses reveal an increase again in trophic state, productivity, and in pH. This eutrophication, which continued throughout the late Holocene, was caused by an exceptionally strong human influence on the catchment of Lake Sämbosjön. The increased supply of nutrients from cleared and deforested catchment soils changed the trophic state and provided the basis for increased lake productivity.  相似文献   

How does landfill leachate affect the chemical processes in a lake system downgradient from a landfill site?     

Thomas Striebel  Wolfgang Schäfer  Stefan Peiffer 《Aquatic Sciences - Research Across Boundaries》1991,53(4):346-366

A field study on the geochemical properties of a chemically-stressed limnic environment was performed in Lake Silbersee, which receives leachate water of high inorganic loading from an upgradient landfill site. The highly concentrated sulfate ion in groundwater, when entering the pore water system of the lake, gives rise to an intensive microbial sulfate reduction. A diagenetic approach was used to explain the existence of a marine-like aqueous system within a geologically slightly acidic aquifer, consisting of a well-buffered lake water and an alkalinity producing, excess sulphide containing sediment pore water system.  相似文献   

南极洲乔治王岛长城湾一年生海冰的发育特征和物理性质   总被引：5，自引：3，他引：5  

秦大河 《冰川冻土》1991,13(2):115-130

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热带太平洋地区SSTA和风应力场的海气耦合模态   总被引：13，自引：4，他引：13  

张勤  蒋贤安  何金海 《热带气象学报》1995,11(1):43-50

按国家气象局“八五”攻关力专家组提出的有关近海热带气候强度突变的标准，对１９７０－１９９１年在我国的近海发生强度突为的热带气旋进行了分类统计，发现如下气候特征：平均每年有８－９个热带气旋移到我国近海时发生强度突变，其中突然减弱的居多，占总个数的７９．６％，突然增强的只占总个数的２０．４％，突然增强只发和天５－１０月，而突然减弱到５－１２月均可发生；突然增强主要出现在浙闽沿海、南海中部，珠江口外西侧  相似文献