福建晋江流域锰负荷分布及源区识别

以福建晋江流域锰元素为研究对象,将整个流域划分为60个子流域并在各子流域出口处设置水质监测断面,分别于丰水期和枯水期对断面锰浓度进行取样测试,研究锰浓度的时空分布特征。结合流量监测和降水资料,利用水文比拟法计算并总结锰负荷的空间分布,基于锰负荷贡献率进行了锰源区识别。结果表明：丰水期锰浓度普遍高于枯水期,西溪锰浓度总体高于东溪。受矿山开采影响,全年锰浓度最大值位于上游双溪与大畬溪交汇处。锰负荷丰水期远高于枯水期,且具有随径流向下游聚集的趋势,最大值位于晋江流域最下游入海口断面。识别出的锰源区主要位于西溪流域以及干流下游临入海口子流域,应在今后的环境综合治理工作中重点关注。     

天山高山区与郊区降水中颗粒物特征的比较

以天山乌鲁木齐河流域为例,运用参数比较法、相关分析法,对降水中粉尘颗粒物特征在高山区和郊区随时间变化特征及其差异进行研究.结果表明,降水中颗粒物的浓度、粒径分布及化学要素组成在两个取样点都具有明显的季节变化.颗粒浓度表现为冬-春季节升高而夏-秋季节降低,与降水量成反向变化,反映了降水受中亚沙尘活动的影响明显.颗粒在冬-...     

Chemical composition of wet precipitation at a developing urban site in southeastern China

A comprehensive study on the chemical composition of wet precipitation was carried out from January 2004 to December 2004 at Jinhua, China. All samples were analyzed for pH, electrical conductivity and major ions （F, Cl, NO3,. SO4^2-, K^＋, Na^＋, Ca^2＋, Mg^2＋. and NH4^＋）. The results showed that SO4^2- is one of the dominant anions, accounting for 66.1% of the measured anions in precipitation, while NH4^＋ and Ca^2＋ account for 56.6% and 33.4% of the measured cations, respectively. Even though the concentrations of SO4^2- and NO3^- were not high relative to those in the northern areas of China, rainwater in the studied area is typically acidic with a volume-weighted mean pH of 4.54 due to the lack of neutralization in precipitation. The fractional acidity value suggested that about 76% of acid was neutralized by alkaline constituents. On the other hand, H^＋ showed no significant correlation with other ionic species, which indicates that its acidity might be attributed to the comprehensive effect of all the acidifying and neutralizing ions rather than one major ion in precipitation. A good correlation between Ca^2＋ and Mg^2＋, as well as between Na^＋ and Cl^-, indicated these ions are commonly of crustal and marine origin, respectively. Other relatively good correlations were observed between NH4^＋ and SO4^2-, Ca^2＋ and SO4^2-, Mg^2＋ and SO4^2-, Mg^2＋ and NO3^-, and Mg^2＋ and Cl^-. These results were attributed to the atmospheric chemical reactions of the acids H2SO4, HNO3 and HCl with alkaline compounds such as NH3 and/or carbonate materials. High enrichment factor of marine source for SO4^2-, Ca^2＋ and K^＋ indicated that large amounts of these ions came mainly from a non-marine source. Similarly, a high enrichment factor of soil for SO4^2-, NO3^- and CI also suggested that most of these ions did not come from soil source.     

中国大陆降水时空变异规律——I.气候学特征

为系统了解大尺度降水气候特征,利用2 300多个国家级气象站逐日观测资料,分析了中国大陆1956—2013年多年平均降水的空间分布和季节性变化规律。主要新认识有:① 暴雨量、暴雨日数和暴雨强度最高的站点在华南沿海,而小雨量、小雨日数最多的站点主要在江南内陆山区、丘陵;东部季风区山地、丘陵多出现低强度降水,平原和沿海易出现高强度降水;② 四季降水量均由西北内陆向东南沿海递增,南方秋季降水量明显小于春季,但华西和江南沿海秋季降水量较多,冬季降水在东南丘陵出现高值中心;③ 珠江和东南诸河流域降水量年内存在2个峰值,其中珠江流域有6月主峰值和8月次峰值,东南诸河流域主峰在6月中下旬,次峰在8月末,长江流域总体表现为单峰型,出现在6月下旬和7月初,西南诸河流域和北方所有流域降水均表现为夏季单峰型;④ 南方各大河流域从2月末到6月中下旬陆续进入雨季,北方各大河流域进入雨季时间集中在6月末、7月初;南、北方雨季结束时间比雨季开始时间集中,从南到北进入雨季时间持续120 d以上,而从北到南退出雨季时间则仅持续不到45 d;⑤ 丰雨期的持续时间,珠江流域从5月初到9月上旬后期,东南诸河从5月上旬到7月上旬,8月末到9月初再度短暂出现,长江流域从6月中下旬到7月中旬,西南诸河从7月中旬到 8月下旬,淮河流域从7月上旬至7月底、8月初,辽河流域在8月初出现极短丰雨期;⑥ 降水年际变异性最高的站点在青藏高原西南、塔里木盆地、阿拉善高原、华北平原北部和汾河谷地,海河流域年降水具有最大的变异系数。     

中国华南陡山沱组烃源岩的形成机制与分布预测

震旦系(埃迪卡拉系)陡山沱组是成冰系(南华系)极端冰期事件结束后首次沉积的泥岩和碳酸盐岩地层,大规模的海侵活动导致在全球广泛发育富有机质黑色页岩,可能是未来深层油气和页岩气勘探的重要烃源岩层.中国华南陡山沱组烃源岩分布广泛,由于受古构造格局、沉积相带等因素影响,烃源岩非均质性强、平面上分布差异大.本文在前人研究基础上,...     

中国极端降水事件的区域性和持续性研究

利用中国542个站1960-2003年逐日降水资料,分析中国极端降水事件的区域性和持续性,研究发现:滇西藏东一带极端降水的持续性较好,但该地区极端降水的区域性较差;长江以南地区夏季极端降水的区域性与持续性均较好,容易导致区域性洪涝灾害的发生;东南沿海冬季极端降水的区域性与持续性均较好,易形成成片且持续时间在3d或3d以上的极端(较强)降水事件;黄河中下游秋季极端降水的区域性与持续性均较好,该地区秋季发生洪涝的可能性较大;除新疆以外,东北、华北以及西北等大部分北方地区极端降水的持续性以及区域性均较差。     

中国极端降水事件的频数和强度特征

使用1951-2004年中国738个测站逐日降水资料,采用百分位的方法定义极端降水事件的阈值,分析了不同持续时间的极端降水事件的时空分布及变化趋势特征。结果表明,极端降水事件多发于35°N以南,特别是在长江中下游和江南地区以及高原东南部,且在这些地区极端降水事件持续时间也较长。季节分布上,主要出现在夏季,以低持续性事件为主。在中国东部地区,持续时间越长的极端降水其强度往往越强。趋势分析表明,全国持续1d极端事件的相对频数具有上升趋势而平均强度具有下降趋势,其空间上均表现为全国大部分上升、华北和西南等地下降的趋势。持续2d以上极端事件在长江中下游流域、江南地区和高原东部等地区有显著增多和增强的趋势,而在华北和西南地区有减少和减弱趋势,但全国平均的趋势不显著。     

兰州市降水同位素变化特征及影响因素

利用2018年4月至2021年4月在兰州市4个站点收集到的349个降水事件样品,对兰州市降水同位素的变化特征和影响因素进行了研究。结果表明：兰州市降水同位素表现出夏季高冬季低的季节变化特征,并且夏半年降水同位素的空间变异性比冬半年显著。兰州市的大气降水线为δ²H=7.34δ¹⁸O+7.28（R²=0.96,P<0.01）,反映了兰州较为干旱的气候特点。在影响因素方面,兰州市降水同位素表现出温度效应。后向轨迹表明,兰州市夏半年降水受到季风水汽和西风带水汽的影响,冬半年降水主要来自于西风带水汽的输送;利用潜在源贡献因子（PSCF）分析法和浓度权重轨迹（CWT）分析法发现,潜在蒸发源区在夏半年主要分布在兰州东部区域,而冬半年几乎不存在潜在蒸发源区。此外,在夏半年,降水事件前几天的对流活动会对降水同位素产生综合影响,累积时间与对流活动的强度及频率有关,在季风初期和末期累积时间较长,季风强盛期较短;在冬半年,降水事件前几天的温度会对降水同位素产生综合影响,累积时间受到冷空气南下频率的影响。以上认识将为季风边缘区水循环过程的研究提供新的视角。     

桂林岩溶区大气降水的化学特征分析

2009年1月至2010年12月期间,对处于岩溶区的桂林市降水进行了连续采样测试分析。研究结果表明:(1)桂林市区降水的pH平均值为4.83,降水的电导率平均值为65μS/cm,SO42-、NO3-和Ca2+、NH4+分别是最主要的阴阳离子。(2)桂林市降水各主要离子含量、降雨量和电导率表现出明显的季节差异,其中Ca2+、Mg2+含量在夏、冬季较高,春、秋季较低。(3)降雨量和TDS呈现出良好的负相关关系, SO42-和NO3-以及Ca2+和Mg2+之间则具有较好的正相关关系。(4)2009—2010年与1994—1995年相比,降水中的离子含量增加了1.16倍,降水的pH值有所增高,但仍在酸雨范围之内。在桂林酸雨形成中,降水的NO3-贡献明显增强。(5)通过2012年3月1—6日连续6天的降水监测,发现pH、降雨量和电导率三者呈现出良好的相关性。      

中国海相烃源岩发育控制因素

烃源岩的形成取决于生烃母质生物的生存环境和有机质良好的保存条件,这两大因素从根本上来说又取决于生物繁殖时和埋藏时的古气候、古洋流、古构造及古环境等各要素的良好匹配。海相高有机质丰度烃源岩的形成与大气中的中等含氧量、干热的气候、冰期-冰后期之交的气温快速转暖、冰川迅速融化所导致的海平面快速上升等密切相关。大洋环流的形成和演变也是控制海相高有机质丰度烃源岩形成的主要因素,上升洋流富磷、富硅、富铁族元素等营养盐和富绿硫细菌极大地促进了有机质生产力、埋藏率的激增。通过研究,建立了中国华南和塔里木盆地寒武系上升洋流分布模式、塔里木盆地上奥陶统良里塔格组台缘斜坡灰泥丘相源岩形成时的反气旋洋流分布模式。研究发现,优质烃源岩仅发育于被动大陆边缘背景下的裂谷、克拉通内裂谷、克拉通内坳陷盆地和克拉通边缘坳陷盆地。欠补偿盆地、蒸发潟湖、台缘斜坡(灰泥丘)和半闭塞—闭塞欠补偿海湾,是高丰度烃源岩发育的有利环境;低的无机物输入和低的沉积速率,有利于高有机质丰度烃源岩形成;呈斜坡的海底地貌,有利于烃源岩形成。     

世界深水含油气盆地烃源岩的发育特征及对中国南海北部深水区烃源岩的启示

国外深水盆地烃源岩发育特征表明:无论是板内的断坳盆地还是板缘的先裂陷后漂移沉积盆地,在裂陷期(断陷期)及坳陷期(漂移期)均有烃源岩分布,大陆边缘盆地不同演化阶段有效烃源岩发育程度存在差别,其中裂陷期非海相(湖相)暗色页岩是最主要和最普遍的生油岩,还可能发育过渡相或近海相的煤系和泥质烃源岩;其次是板内坳陷晚期或板缘漂移期的海陆过渡相、近海相、前三角洲相等有大量的有机质供给或者长期离物源区较近的情况下,烃源岩发育;裂陷晚期和坳陷早期烃源岩一般不发育,但有大量的有机质供给的半封闭浅海—半深海环境可能发育高效烃源岩。国外主要深水盆地中新生界烃源岩发育特征对中国南海北部深水区烃源岩的认识具有重要的指导意义。中国南海北部裂陷早期阶段发育的湖相烃源岩和裂陷晚期发育的海陆过渡相烃源岩为主力烃源岩;南海北部不同盆地坳陷期中新统海相烃源岩差异较大,其中陆源有机质输入不足的琼东南盆地烃源岩稍差些,陆源有机质输入相对充足的珠江口盆地烃源岩较好一些。墨西哥湾和北苏门答腊盆地的勘探实践已经证实了半深海相烃源岩可作为有效油源岩,这对中国南海北部深水区中新统海相烃源岩认识具有很好的借鉴意义。     

秦岭太白山南麓降水中常量无机离子特征及其来源研究

以2011年11月至2014年9月连续采集的74个有效降水样品为研究载体,运用趋势分析法和相关分析法分析太白山南麓黄柏塬地区降水中常量无机离子（NH₄⁺、Ca²⁺、Na⁺、K⁺、Mg²⁺、SO₄^2-、NO₃^-、Cl^-、F^-）的化学特征,并结合富集因子法、端源贡献法及后向气流轨迹模型探究其来源。结果表明：研究区降水中各离子浓度大小顺序为Ca²⁺ > SO₄^2- > NH₄⁺ > NO₃^- > K⁺ > Na⁺ > Mg²⁺ > Cl^- > F^-,主要阳离子是Ca²⁺和NH₄⁺,共占阳离子总量的76.21%,主要阴离子是SO₄^2-和NO₃^-,共占阴离子总量的90.83%。降水总离子年平均浓度为404.64 μeq·L^-1,相对于国内外已研究的其他高山站点偏高,表现出典型的大陆型及人为源干扰的特征。受排放源、气象因子、植被、降水量等因素影响,降水总离子浓度表现出显著的季节差异,依次为冬季 > 春季 > 秋季 > 夏季。源解析结果显示降水中SO₄^2-和NO₃^-95%以上由人为源贡献,Ca²⁺和Mg²⁺主要来源于地壳风化,Na⁺海盐源和非海盐源贡献约各占一半,K⁺主要来自于非海盐贡献,而F^-和NH₄⁺则几乎全部由人为源贡献。不同路径气团影响下的降水离子组分具有明显不同,北方气团途径太原、石家庄、北京、兰州等工业发达城市,工业燃煤交通废气排放量大,降水中SO₄^2-、NO₃^-浓度均偏高,离子总浓度也明显高于南方气团。     

中国西南地区降水氢氧同位素研究进展与展望

中国西南地区属典型的季风气候, 降水的水汽来源及其影响因素非常复杂. 通过检索西南地区有关降水氢氧同位素的文献, 对西南三省一市降水氢氧同位素研究进行了综述. 从已开展研究的区域和站点、 主要采用的样品采集与分析方法、 主要的研究内容(同位素组成、 大气降水线、 氘盈余)和水汽来源、 影响因素以及区内的空间差异等几方面进行总结, 并对今后西南地区降水氢氧同位素的研究进行展望, 为研究区域降水氢氧同位素的进一步研究提供科学指导.     

Non-point source pollution of Wujiang River watershed in Guizhou Province, SW China

The amount of pollution from non-point sources flowing in the streams of the Wujiang River watershed in Guizhou Province, SW China, is estimated by a GIS-based method using rainfall, surface runoff and land use data. A grid of cells, 100 m in size, is laid over the landscape. For each cell, mean annual surface runoff is estimated from rainfall and percent land use, and expected pollutant concentration is estimated from land use. The product of surface runoff and concentration gives expected pollutant loading from that cell. These loadings are accumulated going downstream to give expected annual pollutant loadings in streams and rivers. By dividing these accumulated loadings by the similarly accumulated mean annual surface runoff, the expected pollutant concentration from non-point sources is determined for each location in a stream or river. Observed pollutant concentrations in the watershed are averaged at each sample point and compared to the expected concentrations at the same locations determined from the grid cell model. In general, annual non-point source nutrient loadings in the Wujiang River watershed are seen to be predominantly from the agricultural and meadow areas.     

Impacts of acid mine drainage on a stream in subtropical China during a major flood event

Field and laboratory work was carded out to investigate the chemistry and ecotoxicity of stream water affected by acid mine drainage in a tributary catchment of the Pearl River in subtropical China during a major flood event that corresponded to a return period of 100 years occurred in the study area. The results indicate that stream water was affected by acid mine drainage from the Dabaoshan Mine at least to a distance of 25 km downstream of the mine water discharge point. It appears that sulfide-H^＋ from the waste rock dumps was readily available for discharging and the amount of H^＋ being transported outwards depended on the volume of out-flowing waters. However, there was a lag time for the discharge of the metals. This may be attributed to the slower release of metals, relative to H^＋, because it might take more time for the dissolution of heavy metal-bearing compounds. Fe, Zn and Al were the major metals of potential toxicity contained in the AMD-affected stream water, followed by Mn, Cu, Pb, As, Cd and Ni. Acute toxicity tests show that the AMD-affected stream water at 3.5 km downstream of the discharge point was highly toxic to the test organisms.     

Characteristics of Non—Point Source Pollution in the Watershed of Miyun Reservoir,Beijing,China

Nitrogen and phosphorus are the major nutrients to cause eutrophication to degrade water quality of the Miyun Reservoir,a very important drinking water source of Bijing,China,and they are mainly from non-point sources.The watershed in Miyun County was selected as the study region with a totoal area of 1400km^2.Four typical monitoring catchments and two experimental units were used to monitor the precipitation,runoff,sediment yield and pollutant loading related to various land uses in the meantime.The results show that the total nutrient loss amounts of TN and TP are 898.07t/a,and 40.70t/a,respectively,in which nutrients N and P carried by runoff are 91.3% and 77.3%,respectively.There is relatively heavier soil eroson in the northern mountain area whereas the main nutrient loss occurs near the northeast edge of the reservoir.Different land uses would influence the loss amounts of non-point source pollutants.The amount of nutrient loss from the agricultural land per unit is highest,that from forestry comes next that from grassland is lowest.However,due to the variability of land use areas,agricultural land contributes a lot to TP and forestry lands to TN.     

地下水污染源识别的数学方法研究进展

地下水污染源识别模型可利用有限的观测资料估计污染源位置、污染物泄露强度及其泄露过程,是制定地下水污染修复方案的依据。在阐明地下水污染源识别基本问题基础上,综述了污染源识别研究的两大类数学方法,一类为直接方法,包括反向追踪法和基于正则化的方法;另一类为间接方法,包括基于优化的方法和基于概率统计的方法。同时指出了当前污染源识别数学方法应用中存在的主要问题:地下水污染源识别问题的复杂性、地下水有机污染问题和模型求解效率的低下性。对土壤-地下水的联合管理、基于物联网的地下水污染监测、对非水相流体（Non-aqueous Phase Liquid,NAPL）类污染源识别以及基于图形处理器（GPU）的异构并行计算将是未来研究的重点方向。     

GPM和TRMM卫星日降水数据在黄河源区的适用性分析

通过评估GPM计划三种日降水产品（IMERG-E、 IMERG-L和IMERG-F）和TRMM卫星、 两种日降水产品（TMPA 3B42和TMPA 3B42RT）在黄河源及其周边区域38个台站的适用性, 探究了五种产品探测精度和海拔高度及雨强的相关关系, 结果表明： 在与实测资料的一致性和偏差方面, GPM卫星产品要全面优于TMPA产品。在TRMM卫星产品中, 3B42产品明显优于3B42RT。五种产品的相关系数均表现出明显的从东南到西北递减的趋势, 均方根误差北部普遍低于南部。IMERG产品的探测率（POD）和探测成功率（CSI）都要普遍高于TMPA产品, 而误报率（FAR）则是TMPA 产品更低, 表现更好。五种产品均在个别台站出现了严重误报的情况, 这些台站主要分布在研究区的西北部。IMERG三种产品对于海拔高度的依赖程度具有很强的一致性, 而3B42RT产品对海拔高度几乎没有依赖。除3B42RT产品外, 其余四种产品的偏差均随雨强的增加而增大。在探测率方面, IMERG产品对小雨、 中雨和大雨的探测能力均优于TMPA产品。     

Tectonic and eustatic control on the distribution of black-shale source beds in the Wufeng and Longmaxi formations (Ordovician-Silurian),South China

It is known that high-quality, black-shale source rocks occur in the uppermost Ordovician Wufeng Formation and in the lowermost Silurian Longmaxi Formation in South China. Hence, it is important to understand their lithostratigraphy and the controls on their deposition. A review of lithostratigraphic criteria for subdividing the two adjacent formations provides new regional correlations between the formations and related stratigraphic successions and facies. Both the black shales and the related, overlying flysch deposits at the Ordovician-Silurian transition in South China appear to have migrated northwestward in time and space, reflecting probable flexural control in a foreland basin that developed in response to subduction-type orogeny southeast of the Yangtze block. The black shales also contain K-bentonites from explosive, felsic-intermediate volcanism, the distribution of which also supports orogeny to the southeast. Finally, the analysis of sequence stratigraphy, which shows that the initiation of transgressive system tracts (TST) and condensed section (CS) in the related third-order sequences coincided with the two black-shale horizons respectively, indicates that the main controlling factors for the deposition of the Ordovician-Silurian black shales in South China are (1) northwestwardly migrating, foreland-basin subsidence caused by deformational loading related to episodic accretion of the Cathaysia block to the Yangtze block during this period, and (2) the anoxic, sediment-starved water column caused by rapid rise of the sea-level during the two successive phases of third-order global sea-level rise near the Ordovician-Silurian transition in South China. In future exploration for hydrocarbon source rocks in the area, it is important to consider likely flexural and eustatic causes for subsiding, deep, anoxic seas in recognizing other source rock intervals, and our understanding of the Wufeng and Longmaxi formations may serve as models for future source rock exploration. __________ Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 818–827 [译自: 地球科学—中国地质大学学报]     

Isotope Geochemical Characteristics and Material Sources of Tin--Bearing Porphyries in South China

Tin-bearing porphyries in South China can be divided into the F-rich and F-poorsubtypes. They are high-silica (SiO_2>71%), peraluminous (A/NKC>1.0) and rich inincompatible elements (Rb, Zr, U, W, Sn) and have weak Ce (δCe=0.68-0.82) and strong Eu(δEu=0.01-0.38) negative anomalies. Meantime, they also have low δ_(Nd)(-6.3- -8.4), high~(207)Pb/~(204)Pb (15.588-15.790), medium to high (~(87)Sr/~(86)Sr)_i (0.7084-0.7287) and relatively highδ~(18)O(9.1-10.3‰). These characteristics clearly suggest that the two subtypes of tin-bearingporphyries were derived from the crustal materials. Their differences lie only in the existence ofcertain different components in their source materials. Therefore, there is only one type oftin-bearing prophyry in South China. that is continental crust transformation type.