Behavior of a Small Pulsed River Plume in a Strong Tidal Cross-Flow in the Akashi Strait

We carried out a field study of a small river plume emptying into Osaka Bay near the Akashi Strait in western Japan, to understand the fate of its urban-runoff-laden waters. As the river is weak compared to tidal currents, we find that the behavior of the plume is strongly influenced by phasing between tidal stage and currents (a westward-traveling progressive tidal wave). When the tidal stage rises, sea water floods up the river, and concentrated river effluent cannot be seen in Osaka Bay. During most of the river’s ebb, a topographic eddy transports river effluent towards the energetic Akashi Strait, while strong vertical shear in the tidal flow mixes the effluent with seawater. However, there is a short interval of time during which the direction of tidal flow in the Strait changes direction and the magnitude of the current is weak. At this time, shear is weak enough to allow a stratified plume of concentrated river water to form, and this plume is driven offshore, and into Osaka Bay, by baroclinic circulation. A sewage outfall, which is located very close to the river mouth, is subjected to these same conditions and therefore exhibits similar behavior. Understanding the relation between tidal phase and plume behavior will be useful to Kobe City, as well as other cities in a similar environment, for minimizing the environmental effects of their wastewater and non-point-source runoff.     

乐清湾水质变化及其成因探讨

收集了乐清湾多年的水质监测资料，分析了乐清湾各水质指标在时间和空间上的变化规律。在此基础上，分别从乐清湾外部污染源变化，海岸工程引起的水动力变化和水产养殖业产生的内部污染源的变化等几方面，对乐清湾水质变化的原因进行了探讨。     

Coastal zone management in wales: The information gaps

In 1994 the Countryside Council for Wales, the government nature conservation and countryside advisor in Wales, published a consultation document on marine and coastal policy, and also commissioned research into the status of coastal zone management (CZM) in the Principality. The research, undertaken by the University of Wales Cardiff, investigated CZM from an international, national (U.K.) and Welsh perspective, concentrating on detailed case studies of three areas (including both urban and rural coasts). Policy makers, managers, practitioners and users from all sectors were included in the study which established current activity, identified problems and reviewe future plans. Interviews and questionnaire returns highlighted vital information gaps at all levels. These ranged fom a lack of basic data (including scientific and technical), to a breakdown in communication both within and between organisations, as well as a policy vacuum in both regional and central government.     

海湾扇贝自身污染的研究

在实验室条件下，进行了海湾扇贝自身污染的研究。在海湾扇贝生长的生态过程中，出现了来源于自身新陈代谢产物的有机和无机氮污染，即自身污染。导致ｐＨ和ＤＯ的降低，ＣＯＤ和ＢＯＤ的增加，以及病原生物弧菌的大量繁殖。     

大亚湾海域海水中各种形态磷的研究

根据 1999年 5月 (春季 )的调查 ,统计了大亚湾海域海水微表层、次表层、表层和底层水中各种形态P的含量 ,计算了各种形态P分别占总磷 (TP)和总溶解磷 (TDP)的百分比 ,讨论了各种形态P之间的相互关系 ,分析了影响颗粒磷 (PP)和溶解磷 (TDP)分布的环境因素。结果表明 ,大多数站位微表层对各种形态P产生了富集 ,但是富集概率有所差别 ;大亚湾海域水中P ,除微表层主要以PP形态存在外 ,其余水层均主要以TDP形态存在 ,TDP在所有水层中均以DOP为主要存在形态 ;各个水层中PP是影响TP分布变化的主要因素 :影响PP在微表层、次表层和表层分布变化的主要环境因素为COD ,在底层则为叶绿素a与COD的叠加 ;影响TDP在微表层和底层分布变化的主要环境因素为盐度 ,在次表层和表层则为COD。     

胶州湾水质自动站周边水质及运行效果分析

据2016年胶州湾水质自动监测的数据结果,分析了水质变化趋势,并统计和评价其水质超标情况。结果表明:2016-04—11水质自动站海域溶解氧质量浓度和pH 的日均值均达到二类海水水质标准,达标率为100%;活性磷酸盐年均值为0.023mg/L,无机氮年均值为0.154mg/L,以硝酸盐为主(64.9%);无机氮和活性磷酸盐超标率均为16.7%,而且集中在降雨量较大的8月、9月,营养盐指标超标基本与海泊河的淡水输入有关;叶绿素a质量浓度与溶解氧、pH 和浊度呈显著正相关,浮游植物光合作用对该海域表层海水的水质参数影响较大;自动站监测和人工监测的营养盐在年际变化上呈现较一致的趋势,说明运用水质自动站监测该海域的营养盐变化趋势较为准确。     

蓄水前后三峡库区香溪河沉积物磷形态分布特征及释放通量估算

三峡库区汛末蓄水过程改变了支流库湾沉积物赋存环境,继而影响沉积物磷形态的分布特征和沉积物-水界面过程.本文通过对2016年8月(蓄水前)和10月(蓄水后)香溪河库湾沉积物和上覆水样品的采集分析,分析了蓄水前后库区干流和支流库湾底部沉积物磷形态分布特征及赋存的环境条件,估算了沉积物-水界面PO3-4-P交换通量.结果表明:蓄水后沉积物上覆水pH增加,碱性增强;Eh减少,还原性增强.沉积物中各形态磷相对含量由Na OH-PHCl-POP转变为HCl-POPNa OH-P,沉积环境的改变是磷形态变化的根本原因.沉积物中TP增加了1.3倍,上覆水ρ(PO3-4-P)是蓄水前3.7倍,间隙水ρ(PO3-4-P)是蓄水前8.3倍,增加了香溪河库湾沉积物营养盐释放风险.蓄水前后香溪河沉积物PO3-4-P总体均表现为"源",但PO3-4-P扩散通量由蓄水前的-0.002 9~0.005 9 mg·(m~2·d)~(-1)增加为蓄水后的0.006 7~0.107 1 mg·(m~2·d)~(-1),蓄水后香溪河库湾底部沉积物磷释放量增加.     

环胶州湾河流入海口CDOM吸收光谱特征

为深入认识河流对胶州湾水体有机碳的贡献,于2016年4月-2017年2月对环胶州湾河流入海口进行双月采样,通过分析水体中DOC（溶解有机碳）和POC（颗粒有机碳）质量浓度及CDOM（有色溶解有机物）的吸收光谱特征,揭示环胶州湾入海口有机碳的分布特征,辨析CDOM的组成和来源,探讨其与主要环境因素的关系.结果表明:①环胶州湾河流入海口DOC和POC质量浓度范围分别为0.98~32.75和0.13~22.40 mg/L,其中李村河口最高,轮渡和大港相对较小.②a（355）（CDOM的吸收系数）变化范围为0.23~16.35 m-1,存在明显的季节性差异,与盐度成反比,其分布与DOC和POC基本一致.③研究区域水体中,表征CDOM分子组成、来源及芳香化程度的S_R[光谱斜率比,S_g（275~295 nm）/S_g（350~400 nm）]和A_{250 nm}/A_{365 nm}存在显著的时空差异.④夏季、秋季CDOM的整体分子量水平高于春季、冬季;轮渡、大港、板桥坊河和娄山河S_R相对较高,CDOM组成趋向于蛋白类或富里酸类物质.⑤轮渡、大港和镰湾河A_{250 nm}/A_{365 nm}相对较高,类腐殖质的芳香化程度较低,受海源控制;其他河口A_{250 nm}/A_{365 nm}相对较低,CDOM以陆源输入为主,其类腐殖质的芳香化程度较高,结构相对稳定而不易降解.⑥CCA（Canonical Correspond Analysis,典范对应分析）结果表明,DOC与CDOM吸收特性存在较好的相关性,河口CDOM主要来自地表径流,温度和DO是影响CDOM时空分布的主要因素.研究显示,CDOM的组成、降解的难易程度与来源密切相关,秋季生物量丰富,水体中腐殖酸所占比例增大,CDOM芳香度较高,不容易被降解.      

Temporal and spatial changes of microbial community in an industrial effluent receiving area in Hangzhou Bay

Anthropogenic activities usually contaminate water environments, and have led to the eutrophication of many estuaries and shifts in microbial communities. In this study, the temporal and spatial changes of the microbial community in an industrial effluent receiving area in Hangzhou Bay were investigated by 454 pyrosequencing. The bacterial community showed higher richness and biodiversity than the archaeal community in all sediments. Proteobacteria dominated in the bacterial communities of all the samples; Marine_Group_Ⅰ and Methanomicrobia were the two dominant archaeal classes in the effluent receiving area. PCoA and AMOVA revealed strong seasonal but minor spatial changes in both bacterial and archaeal communities in the sediments. The seasonal changes of the bacterial community were less significant than those of the archaeal community, which mainly consisted of fluctuations in abundance of a large proportion of longstanding species rather than the appearance and disappearance of major archaeal species. Temperature was found to positively correlate with the dominant bacteria, Betaproteobacteria, and negatively correlate with the dominant archaea,Marine_Group_Ⅰ; and might be the primary driving force for the seasonal variation of the microbial community.     

基于多元统计分析的辽东湾沉积物痕量金属地球化学特征

为研究辽东湾表层沉积物中痕量金属的地球化学特征和可能产生的生物效应,于2015年在辽东湾设置38个采样点,采集表层沉积物样品,测定其中13种痕量金属污染物的含量,并采用多元统计分析法对其地球化学特征进行研究. 结果表明:辽东湾表层沉积物中w(Al)、w(V)、w(Cr)、w(Mn)、w(Fe)、w(Co)、w(Ni)、w(Cu)、w(Zn)、w(As)、w(Cd)、w(Ba)和w(Pb)平均值分别为55 726.95、76.21、35.59、852.85、30 482.16、11.98、27.88、21.60、76.53、9.16、0.17、396.78和21.72 mg/kg;其中w(Al)最高,占63.51%;w(Fe)其次,占34.74%. 多元统计分析结果表明,痕量金属受氧化还原环境影响强烈,V、Co、Ni、Cu、Zn、As、Cd在沉积物的氧化还原循环中易被Fe氧化物吸附,与Fe氧化物产生共生关系. Ba与Pb存在共生关系,具有相似的物质来源和地球化学特征;Mn是海洋沉积物中主要化学成分;Cr一般和沉积物中的陆地碎屑相结合. 生态效应浓度评价表明,Ni和As偶尔会产生不利的生物效应,产生几率分别为97%和63%;Ni、As、Cu、Pb和Cr长期暴露会产生毒性效应,产生几率分别为100%、94%、74%、6%和3%,Zn和Cd不会产生毒性效应. 根据对生物产生负面效应和毒性效应的概率,痕量金属污染程度的排序为Ni＞As＞Cu＞Pb＞Cr＞Zn=Cd.