南京三汊河口人行桥修建对上游河口闸泄流的影响

针对南京三汊河口人行桥修建对上游河口闸泄流的影响,应用河工模型进行了研究。根据2014年1月实测的地形资料,建立了水平比尺100、垂直比尺50的三汊河口河工模型。试验数据在与数值计算数据对比的基础上,研究了人行桥建设前后闸下水位、流速等水力要素的变化情况。结果表明,人行桥修建后桥墩上游水位有所升高,流速有所降低,河道主流线向左略有偏移,但影响较小,不会产生河口闸泄流、行洪的安全问题。     

典型滩涂环境因子对植物群落空间分布的影响

长江口滩涂生境具有较高的环境异质性,导致不同滩涂植物群落的分布特征存在显著差异。为分析长江口典型滩涂植物群与环境因子的关系,在崇明东滩和奉贤金汇港两个典型滩涂对其环境因子及植物群落特征进行了采样分析。分析结果表明,滩涂随着高程的增加,受潮汐的影响逐渐减少,环境因子呈现一定的规律性变化,滩涂植物对环境因子具有不同的适应力是导致长江口盐沼植被带状分布的重要因素。崇明东滩作为植物群落较为成熟的滩涂,芦苇和互花米草的生长表现沿高程呈"V"型。奉贤金汇港作为植物建群较短的新生带滩涂,互花米草的生长表现沿高程呈梯度分布。两区域植物群落表现不同的主要原因有可能是建群时间、演替阶段、滩涂受潮汐作用和立地条件等造成的。     

长江口北槽潮波对地形变化的响应研究

以长江口北槽为研究背景,建立了二维潮流数学模型,在模型验证良好的基础上,研究了北槽潮波传播对工程与地形变化的响应。研究表明,长江口深水航道治理工程完成后,北槽地形未发生调整前,北槽潮波高、低潮位均升高,潮差减小,涨、落潮相位明显滞后,潮波变形加剧,涨落急流速均呈增大趋势;北槽水深增加后,高、低潮位随之降低,潮差增大,落潮相位略有提前,涨潮相位变化相对较小,潮波变形逐渐趋缓,涨急流速减弱,落急流速增强。     

天津市用于滨海河口生态补水的非常规水资源估算

随着天津滨海河口入海径流量逐年降低,以及城市水资源供需矛盾日益加剧,入海径流量远不能满足目前滨海河口生态需水量,因此,非常有必要开发非常规水源对滨海河口进行生态补水。在天津非常规水源(包括海水、雨水和再生水)现状分析的基础上,通过水资源利用途径分析和水量估算,得出雨水和再生水资源的可利用量完全可以满足滨海河口适宜生态需水量,并提出了滨海河口生态补水的措施。     

近百年来人类活动对鸭绿江口河床演变影响的重矿物沉积记录

利用2006在鸭绿江河口西汊道采集的编号为YLJ-40的样品的平行样,选取了40个样品对柱状沉积物中0.063～0.125 mm粒级的重矿物特征进行了矿物学的分析与测试,重矿物30种,包括铁矿类4种、主要造岩矿物6种、帘石类5种、辉石与闪石类6种、变质矿物9种（包括指示性重矿物4种）。重矿物的沉积记录显示出西水道海陆交互的沉积历史,结合210Pb测年数据和前期研究成果,揭示了该区域近百年来人类活动对河床演变的深刻影响。     

椒江河口形态变化对风暴潮位的影响——以9711号台风为例

为了探究河口形态变化对天文潮和风暴潮的影响,应用二维水动力模型对椒江河口的风暴潮进行模拟。模型重现了9711号台风引起的风暴潮,并利用实测和预报资料对风场、天文潮位、风暴潮位进行了验证。基于围垦规划的思路,从北岸延伸、南岸延伸、两岸同时延伸和河口收窄四种河口形态变化的角度出发,设置了四组试验方案,分别建立天文潮和风暴潮模型。结果表明,河口形态不同方式的改变对天文高潮位、风暴高潮位和风暴增水有着不同形式和程度的影响,对比分析前后方案的流场可以初步探究其变化的原因。本文成果有助于认识河口形态对河口动力的影响,为海洋防灾减灾提供参考。     

Trace metals in the marine bivalve Macoma balthica in the westerschelde estuary, The Nertherlands. Part 3: Variability of the role of cytosol in metal uptake by the clams

Tellinid clams Macoma balthica were sampled every 2 months for 2.5 years at two locations from the Westerschelde estuary (The Netherlands) and submitted to in vitro short-term exposure to Cd, Cu and Zn. Total and heat-stable cytosolic metal concentrations have been measured before and after exposure to study the effects of the sampling season on metal uptake by the bivalve. We observed much higher uptakes of Cd and, to a lesser extent, Cu in winter than in summer, while Zn appears to be constantly regulated. These phenomena are amplified in the cytosol, especially for Cd, a non-essential element, for which the concentrations after exposure can reach 35–45 μg·g⁻¹ (dry wt.) in winter, but only a maximum of 0.5 μg·g⁻¹ in summer, all natural values being between 0.01 and 0.1 μg·g⁻¹ on average. The contents (μg) of the various elements, either at the total or at the cytosolic level, are not constant, hence showing that the seasonal body weight fluctuation of the clams (dilution or concentration effect) is not the only parameter responsible for the metal uptake variability. Furthermore, we have shown that the proportion of cytosolic metal is not constant, but increases with the absolute cytosolic concentration up to 35–40. Therefore, the cytosolic phase of the cells plays a growing role in Cd, Cu and Zn storage as long as their total concentration increases.     

Geochemical and microfaunal proxies to assess environmental quality conditions during the recovery process of a heavily polluted estuary: the Bilbao estuary case (N. Spain)

This study explores the eventual environmental improvement of the Bilbao estuary (northern Spain), from 1997 to 2006, in order to assess current estuarine restoration being undertaken as part of a Revitalization Strategic Plan. The monitoring programme is based on spatial and temporal variation in the distributions of both benthic foraminiferal assemblages and heavy metals contained in surficial sediments from the polluted intertidal flats. The overall pattern shows a decreasing metal concentration; however, reversals to this trend are noticed in the middle estuary. From 2000 to 2003, a significant decrease in heavy metal concentration was observed which is most likely related to the implementation in 2001-2002 of the biological treatment at a central wastewater treatment plant. Although the metal concentration decreased by 85% for some elements, these values still remain considerably high. No significant change occurred between 2003 and 2006 in metal concentrations. During the monitoring period the estuary channel presented environmental conditions close to azoic in 3/4 of its watercourse. Only in the year 2006, the two lowermost estuarine samples exhibited an increase in microfaunal densities. These samples were dominated by pollution-resistant estuarine species. The fact that estuarine sediments quality is recovering very slowly seems to be caused mainly by the resuspension of accumulated contaminants in the sediments due to dredging and working activities in the estuary. Thus, local authorities should consider also the clean up of the pollutants stored in the sediments, not seeking only the achievement of the water quality standards, as these polluted sediments can act as source of contamination.     

应用PCR-DGGE技术分析长江口低氧区的细菌群落组成

应用PCR结合变性梯度凝胶电泳（PCR-DGGE）技术对长江口外低氧区的细菌群落组成和优势菌群进行了分析。对25条DGGE条带进行了克隆、测序,所得到的细菌16SrDNA基因V3区序列进行了系统进化分析。结果显示这25条条带分别归属于4个细菌类群：变形菌门（Proteobacteria）、拟杆菌门（Bacteroides）、厚壁菌门（Finnicutes）和蓝细菌门（Cyanobacteria）。其中有16条分别与变形细菌亚群的γ-Proteobacteria和δ-Proteobacteria相似。时空分析发现,低氧水体的细菌群落组成与非低氧水体的组成不同,低氧水体包括变形菌门（Proteobacteria）、拟杆菌门（Bacteroides）、厚壁菌门（Finnicutes）和蓝细菌门（Cyanobacteria）,非低氧水体中没有发现蓝细菌门（Cyanobacteria）。并且8月份低氧水体中Flavobacteria为优势菌群。     

剧烈变化的径流对九龙江河口流动特性的影响

为了认识不同径流与潮流博弈引发的河口流动特性的变化规律,采用数学模型和大型河口物理模型耦合的方法,系统研究了九龙江下游北溪浦南水文站、西溪郑店水文站以下广大河口区域的流场及水位场的变化。结果表明,天然状态下,当九龙江径流为15 540、2 896、374m3/s且河口恰遇典型日天文大潮时,潮流界分别位于甘文尾后的红树林海洋自然保护区、南北中港以及西溪河道的渡头村和北溪河道的科坑村,径流变化可使潮流界上溯约35km;不同径流条件下河口三角洲的南港、中港、北港行洪和纳潮的分流比及流动特性发生显著变化;九龙江葫芦状河口及厦门岛周边存在径流对潮位影响的分界区,厦门岛北支口门区域受九龙江北溪和西溪径流影响很小。