Assessment of seasonal and polluting effects on the quality of river water by exploratory data analysis

22 Physico-chemical variables have been analyzed in water samples collected every three months for two and a half years from three sampling stations located along a section of 25 km of a river affected by man-made and seasonal influences. Exploratory analysis of experimental data have been carried out by box plots, ANOVA, display methods (principal component analysis) and unsupervised pattern recognition (cluster analysis) in an attempt to discriminate sources of variation of water quality. PCA has allowed the identification of a reduced number of “latent” factors with a hydrochemical meaning: mineral contents, man-made pollution and water temperature. Spatial (pollution from anthropogenic origin) and temporal (seasonal and climatic) sources of variation affecting quality and hydrochemistry of river water have been differentiated and assigned to polluting sources. An ANOVA of the rotated principal components has demonstrated that (i) mineral contents are seasonal and climate dependent, thus pointing to a natural origin for this polluting form and (ii) pollution by organic matter and nutrients originates from anthropogenic sources, mainly as municipal wastewater. The application of PCA and cluster analysis has achieved a meaningful classification of river water samples based on seasonal and spatial criteria.     

Seasonal and spatial variations in major and trace elements in a regulated boreal river (Esse River) affected by acid sulphate soils

In coastal areas of Finland, extensive artificial drainage of Holocene sulphide‐bearing marine and lacustrine sediments has resulted in development of acid sulphate (AS) soils (pH 2.5–4.5) over an estimated area of approximately 3000 km². During heavy rains and snow melting, these soils are flushed resulting in discharge of acidic and metal‐rich waters that strongly affect small streams. However, the total and precise effects in the important and large rivers are not well understood. In this study, the impact of AS soil occurrence and hydrological changes on water quality was determined in an important regulated boreal river (Esse River) having a catchment area of 2054 km² partially covered with AS soil (39 km²). Water samples, collected at five sites along the river during four carefully selected events, were analysed for pH, total organic carbon, conductivity and the following elements/anions: Al, Ba, Br, Ca, Cd, Cl^?, Co, Cr, Cu, Fe, K, La, Mg, Mn, Na, Ni, NO, Rb, Sc, Si, SO, Sr, Th, Y and Zn. There is a clear spatial correlation between AS soil occurrence and elevated element concentrations in the river water, especially when the conditions change from dry/warm (summer) to wet/cool (autumn). During the rains in autumn these soils are extensively flushed and concentrations of Co, La, Zn, Y, Mn and Al are increased between three and nine times towards the outlet. The buffering capacity of the river was, however, high enough to prevent a detrimental drop in pH. Another intriguing feature is substantially elevated concentrations of several potentially toxic metals (Cr, Cd, Cu) in the middle reaches in winter when the river is ice‐covered. Since no external source for this was found, we suggest an internal source operating by an as yet unknown mechanism. During baseflow in summer, the concentrations of several solutes reach minimum concentrations. Copyright © 2005 John Wiley & Sons, Ltd.     

基于聚类分析与因子分析的西藏高原南部湖水水化学特征研究

基于聚类分析和因子分析研究了西藏高原南部27个湖泊水样的水化学特征及影响因素。聚类分析结果表明受气候条件地带性和湖泊补给来源多样性影响,青藏高原湖水水化学参数具有空间差异,27个水样可分为2个大类和5个亚类,其水化学类型符合湖泊演化过程。因子分析结果表明不同类型的湖泊水化学特征和影响因素不同,淡水湖水化学类型主要为Na-HCO₃,提取出2个主因子,分别揭示了碳酸盐和硅酸盐矿物溶解、硫酸盐矿物和岩盐溶解对其水化学特征的影响。咸水湖水化学类型主要为Na-SO₄,提取出3个主因子,分别揭示了碳酸岩矿物溶解、硫酸盐矿物和岩盐的溶解以及人类活动对其水化学特征的影响。盐湖水化学类型主要为Na-Cl,提取出2个主因子,分别揭示了岩盐矿物及硅酸盐矿物溶解、硫酸盐矿物和碳酸盐矿物溶解对其水化学的影响。     

柴西地区古近系和新近系地层水化学特征及其成因

在系统收集柴达木盆地西部地区各主要油田古近系和新近系油田地层水化学测试分析资料后,发现该地区地层水矿化度很高,均值为166 g?L^-1,最低值达到3.90 g?L^-1,具有高浓缩地层水特征,属卤水级,且主要是由Na⁺+K⁺组成的CaCl₂型水,反映封闭条件好。各主要离子在纵向上呈增加和减小交替变化的趋势,矿化度随深度的增加表现为先减小后增大的趋势,这与中国东部盆地明显不同。各离子比值（钠氯系数、变质系数和脱硫酸系数）均反映出该地区地层整体封闭性好。上、下油砂山组Ca²⁺富集主要由白云石化作用导致,其次是方解石溶解,白云石化同时也使其Mg²⁺贫乏。上、下干柴沟组仅有少数数据点表现出Ca²⁺富集,应是方解石溶解导致的,绿泥石化是其Mg²⁺贫乏的主要原因。SO₄^2-亏损主要是由大量膏岩的沉淀和油藏中大量硫酸盐还原细菌的还原作用导致。除了SO₄^2-被还原会产生HCO₃^-之外,有机质成熟过程中CO₂及有机酸的加入也可造成地层水中HCO₃^-质量浓度的增加。     

同位素与水文地球化学方法在矿井突水水源判别中的应用

通过对抚顺老虎台矿区各类水体的同位素及水化学特征研究,阐述了地表水与矿井各开采水平及73003^#突水点的同位素和水化学特征及其相互关系,论证了矿井上覆白垩系砾岩含水层与73003^#突水点的联系。研究表明:73003^#突水点的同位素及水化学特征与地表水及其他开采水平差异较大,而与白垩系砾岩水的同位素及水化学特征相似。根据同位素、水化学特征及混合计算发现,突水点的水是白垩系地下水与第四系地下水的混合,且白垩系砾岩水占67%,占主导作用;矿井突水通道为活化的F₁断层。     

罗溪温泉水文地球化学特征及热水来源

本文选取江西省罗溪温泉为研究对象,综合应用地质、水化学和同位素等手段,对其水化学特征及来源进行系统研究,为热水的可持续开发利用提供了科学依据。研究表明:温泉为HCO_3·CO_3-Na型热水,可作为含F和H_2S的医疗热矿水进行开发,但不宜作为灌溉用水使用。通过分析温泉的D、~(18)O及~(87)Sr/~(86)Sr同位素资料,可知热水的补给来源为温泉东西方向海拔约950m的山区的大气降水,降水与地壳中岩石相互作用形成温泉。利用Person法修正热水的~(14)C年龄约为19 800年。通过计算推测热储温度约为82℃,循环深度为1 900m左右。温泉为花岗岩中地下水获得大气降水补给入渗后,经深循环加热上升出露而成。     

中国盐湖卤水蒸发实验研究进展

中国盐湖众多,盐湖中矿产资源丰富,受盐湖所处地理位置和自然气候条件限制,盐湖开发采取了不同的工艺路线。根据盐湖卤水的水化学类型不同可将盐湖分为3类,即碳酸盐型、硫酸盐型和氯化物型,每种盐湖类型盐湖卤水相图各异,盐类矿物组成也不相同。针对3种类型盐湖,中国盐湖研究人员做了大量的盐湖卤水蒸发实验研究工作,取得了不少科研成果。汇总了前人针对3种类型盐湖卤水所进行的蒸发实验研究成果,分析了各类型卤水蒸发浓缩规律和盐类矿物特征,为相似盐湖卤水蒸发实验研究提供参考。     

三山岛金矿深部开采水文地质浅析

介绍了三山岛金矿区的水文地质概况,重新进行了深部水文地质条件的分区,并对各区进行了较为详细的水力学及水化学特征剖析,以便更好的指导深部地下水防治工作.     

河北承德中部富锶地下水与地质建造相关性分析

承德中部地区富锶地下水分布较广,本次工作在不同地质建造区采集水样62件,土壤和岩石样品143件,水样中锶含量介于0.11～2.32 mg/L之间,其中锶含量≥0.40 mg/L、达到富锶地下水界限含量的水点共有46个,占全部水点的74.19%。pH为7.16～8.39,属于中性-弱碱性水,水化学类型主要为HCO₃- Ca、HCO₃·SO₄- Ca型,水体中Sr²⁺与其他主要离子成分相关性较好,均受岩石风化作用控制。碎屑岩建造中地下水Sr²⁺含量最高,平均值0.75 mg/L,在变质岩建造中地下水 Sr²⁺含量平均值0.51mg/L,第四系松散堆积物中地下水Sr²⁺含量平均值0.55 mg/L,火山岩建造中地下水Sr²⁺含量最低,平均值0.43 mg/L。不同地质建造岩石中的锶含量差异较大,变质岩建造中锶含量最高,平均含量499.94 mg/kg,其次为碎屑岩建造,锶含量平均值为490.77 mg/kg,火山岩建造中锶含量最低,平均值为373.19 mg/kg。地下水中锶元素主要来源于基岩,二者锶含量具有正相关关系,碎屑岩建造及其水体中锶含量均较高,火山岩建造及其水体中含量最低,相比火山岩和变质岩建造,碎屑岩类建造中锶元素更易于向地下水中迁移。     

三屯河流域平原区地下水化学组成特征及变化

该文依据水文地质条件将三屯河流域平原区划分为单一结构潜水子系统和多层结构潜水 -浅层承压水子系统及深层承压水子系统。通过地下水水质简分析数据 ,分析了各地下水子系统中主要离子 ,TDS和水化学类型的特征及其变化 ,并初步讨论了地下水系统的水循环特点