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胶州湾李村河口沉积物中重金属分布特征及其控制因素 总被引：6，自引：2，他引：6
对胶州湾李村河口4个站点沉积物中的酸可挥发性硫化物(AVS)以及同步提取金属元素(SEM,包括Cu,Cd,Ni,Pb和Zn)的含量进行测定,以研究重金属元素在河口海湾沉积物中的分布特征及影响其分布的因素。结果表明,J1站表层沉积物中同步提取金属含量高于其它站点;除J1站外其他站点的同步提取金属的总量随沉积物深度变化范围不大;J1站的SEM/AVS比值始终小于1,其他站点SEM/AVS比值只在沉积物浅表层大于1。此外,AVS和同步提取Fe的含量对沉积物中同步提取金属的分布有着重要影响,其他的因素如有机质的含量等也会对沉积物中同步提取金属的分布产生影响。 相似文献
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九龙江口表层沉积物重金属的污染特征与来源分析 总被引：1，自引：0，他引：1
为了解九龙江口表层沉积物重金属的污染特征，作者于2013年9月在九龙江口进行了表层沉积物采样调查分析，结果表明：沉积物中Cu、Pb、Zn和Cd的空间分布较为相似，高值区均分布在南溪入海口和海门岛下游海域，Cr含量的高值区也分布在南溪入海口附近。聚类分析将采样点位分为4类：第一类主要分布在河口区外侧，沉积物中油类含量较高；第二类主要分布在南溪出海口，硫化物、Zn和Cr的含量较高；第三类分布在河口区中北部，污染物含量处于中等水平；第四类主要分布在海门岛下游海域，硫化物、TOC、Cu、Pb和Zn含量较高。地质累积系数评价显示：Hg、Cu、Pb、Zn、Cr、As处于未污染到轻度污染水平，Cd为轻度污染到重度污染水平；Zn、Cr、Cd的Igeo指数相对较高，第二类和第四类站位的Igeo指数相对较高。相关分析表明，硫化物与Cu、Zn、Cd正相关性较高，Cu与Zn、Cd、Cr正相关性较高，Pb与Zn、Cd正相关性较高，Zn与Cd、Cr正相关性较高。主成分分析表明，河口沉积物重金属主要有以下几个可能来源：流域和河口的工农业活动和采矿活动、流域水土流失、流域自然风化。针对河口沉积物重金属污染，流域-河口污染控制与生态修复需采取以下措施：工业污染的控制、农业污染控制、养殖污染的控制、植树造林与河岸带绿化和矿山生态恢复。 相似文献
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渤海中部表层沉积物中重金属赋存相态及来源 总被引：1，自引：1，他引：0
近年来由于环渤海经济圈的快速发展,渤海接受了来自周边河流、沿岸排污及海上油气开采所产生的大量的重金属等污染物质,使得渤海的生态环境系统面临前所未有的压力。本文采用电感耦合等离子质谱仪（ICP-MS）对采自渤海中部的25个表层沉积物样品中的Cu、Co、Ni、Zn、Pb、Cr、Cd等重金属元素的含量和赋存相态进行了分析,探讨了重金属分布规律、污染状况及来源。研究结果表明,Cu、Co、Ni、Zn、Cr在渤海湾的近岸区域和渤海中部泥质区有较高的含量,而Pb和Cd则在整个研究区的含量都较高;表层沉积物中Cu、Co、Ni、Zn、Cr主要以残渣态形式存在,而Pb和Cd则具有较高的非残渣态含量;生态风险评价结果表明该区表层沉积物未受到Co、Ni、Cr的污染,Cu、Zn、Pb和Cd则为未污染-中等程度污染。重金属元素Co、Ni、Cr以自然来源为主,在沉积物中的分布主要受沉积物物质组成的影响,而Cu、Zn、Pb,尤其是Cd,则受到了人类活动的显著影响。黄河沉积物是研究区表层沉积物中重金属的主要来源,影响范围涵盖了本区大部分区域,但在研究区的北端受到滦河来源物质的影响,渤海湾和研究区中部则受到海河物质和大气沉降来源重金属的一定影响。 相似文献
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厦门西海域沉积物中重金属的赋存状态及潜在迁移性 总被引：1，自引：0，他引：1
以厦门西海域沉积物为研究对象,利用改良BCR连续提取法分析了沉积物样品中Zn、Mn、Cr、Cu、Cd和Pb的赋存状态,并通过潜在迁移指数（PMI）探讨了沉积物中重金属的潜在迁移风险.结果表明：6种重金属总量在厦门西海域沉积物中由大到小的顺序为：Mn〉Zn〉Cr〉Pb〉Cu〉Cd,其中Mn和Zn的含量达到了1 471 mg/kg和231 mg/kg.与沉积物质量标准对比,沉积物样品中Zn、Cr、Cu和Pb的含量较高.改良BCR连续提取表明6种金属中Zn、Cr和Cu主要以残渣态存在,Mn和Cd主要以酸溶态存在,Pb则以可还原态为主.厦门西海域沉积物中6种重金属的潜在迁移指数大到小的顺序为：Mn〉Cd〉Zn〉Cu〉Pb〉Cr,其中Mn和Cd的潜在迁移危险最大. 相似文献
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2015年7月在泰国曼谷湾邦巴功河河口采集了1根1.5m长的沉积物柱样,分析了样品中重金属元素(Cd、Pb、Co、Ni、Cu、Cr、Zn)含量,进行了粒度和~(210)Pb、~(137)Cs活度测试,使用地累积指数、元素污染指数和潜在生态风险参数对重金属污染情况进行评级,并结合实际情况对污染来源进行了推断。结果表明:沉积柱状样210 Pb、137 Cs活度测试结果计算获得的沉积速率约为2.3cm/a,沉积物柱状样记录了1948—2015年的沉积情况。7种重金属元素含量均值分别为0.11、29.60、19.78、44.18、28.99、80.93、99.01mg/kg。重金属含量较20世纪都有所增长,Cd、Zn、Pb、Cr在整段沉积时间框架内增长明显。元素富集程度顺序为CdZnPbCrCuNiCo,Cd元素污染程度最为严重,Pb、Cu和Zn为偏中度污染,Cr、Ni和Co为轻度污染。单一重金属生态风险系数Eir评级顺序为CdPbCuNiCoCrZn。其中Cd为很强至极强生态危害,Pb为轻微至中等生态危害。Cd、Zn、Cu和Pb元素没有超出泰国沉积物环境质量基准规定的效应区间低值,Ni超出效应区间低值,但没有超过效应区间中值。重金属元素与Al较差的相关性表明重金属元素主要是非自然来源,Cd、Cu、Zn可能源于金属冶炼和交通,此外,Cd还可能存在其他未知工业污染来源,受人类活动影响较大。Cr可能源于纺织业发展。1990年之后较1990年之前重金属元素之间的相关性更差,指示1990年之后相比1990年之前重金属污染来源更复杂。 相似文献
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对2017年4月采集的安海湾、围头湾表层沉积物中7种重金属Cr、Co、Ni、Cu、Zn、Cd、Pb含量进行测定,结果显示,这7种重金属的含量平均值依次为96. 99、13. 35、33. 53、39. 68、132. 87、0. 17、39. 10μg/g;除Co外,其它重金属含量平面分布总体呈现由西北向东南降低的趋势,在靠近陆域的东南部有少量回升,可能与陆源输入有关,Co的分布特征没有明显的规律性;调查站位中Cd和Pb含量均符合第一类海洋沉积物标准,Cr、Cu和Zn含量符合第一类海洋沉积物标准的站位分别占35%、71%、71%,其余站位符合第二、三类海洋沉积物标准.利用主成分分析法分析安海湾、围头湾中重金属的主要来源,结果显示,Cr、Cu、Zn、Cd和Pb主要来源于人为排污输入,Ni主要来源于岩石风化等地球化学过程和人为排污输入,Co主要来源于岩石风化等地球化学过程.采用潜在生态危害指数法评价安海湾、围头湾重金属污染程度和潜在生态危害,结果显示,研究区域内的综合潜在生态风险评价为强生态危害,应该采取相应措施控制污染源加强环境保护. 相似文献
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珠江口沿岸牡蛎养殖场沉积物及牡蛎体内重金属含量与评价 总被引：10，自引：0，他引：10
应用原子吸收分光光度计对珠江口9个牡蛎养殖场沉积物及近江牡蛎Crassostrea rivularis样品中的Cd、Cu、Zn、Pb、Cr和Ni的含量进行测定。结果显示,沉积物中的Cd、Cu、Zn、Pb、Cr和Ni的平均含量分别为0.35—3.8、32.4—108.0、58—395、13.2—96.1、14.7—39.9和9.35—40.15μg.g-1干重;牡蛎体内Cd、Cu、Zn、Pb、Cr和Ni的平均含量分别为0.11—12.07、128.8—380.6、1 456.2—1 938.4、0.43—0.98、3.26—10.53和1.44—3.31μg.g-1干重。河口区沿岸养殖牡蛎与沉积物中的Cd、Cr含量具显著相关(p<0.01;p<0.05),可作为Cd和Cr污染的良好指示生物。所有采样点牡蛎体内Pb和Cr含量均低于我国颁布的无公害水产品质量安全标准,但6个采样点的Cd含量略超过安全标准(1.00μg.g-1湿重);4个采样点的Cu含量略超过安全标准(50.00μg.g-1湿重),应引起有关部门的重视。 相似文献
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分析研究了兴化湾中部表层海水Cu、Pb、Zn、Cd、Cr、Hg、As的含量发现,表层海水中Cu、Pb、Zn、Cd、Cr、Hg、As含量均符合海水水质一类标准,对表层沉积物中Cu、Pb、Hg、Cr、Cd、As等6种重金属含量分析表明,6种重金属含量均符合海洋沉积物质量一类标准.表层海水中重金属与环境因子相关性分析表明,6种重金属与环境的相关性在不同季节中存在差异;而表层沉积物中重金属与环境因子的分析表明,重金属具有相近的来源,有机质对沉积物中重金属的含量分布具有重要影响.主成分分析结果表明,兴化湾中部表层沉积物7种重金属主要来源为有机质的降解、沉积环境本身及工业排污的影响,其贡献率分别为59.48%、15.30%、10.98%,3个主成分的贡献率合计达到85.76%.潜在生态危害指数法评价结果表明,Cu、Pb、Zn、Cd、Cr、Hg、As均属轻微生态危害. 相似文献
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Dynamics of Turbidity in the Tweed Estuary 总被引：1，自引：0，他引：1
Results are presented of turbidity measurements made in the Tweed Estuary during 14–29 September 1993. The observations covered a spring-neap period of very strong and relatively weak tides, which included strong wave activity at the mouth of the estuary, the aftermath of a strong freshwater inflow event and a minor inflow event which coincided with neap tides. Turbidity levels between the mouth and the limit of saline intrusion during this period were observed to lie in the range 2–30 ppm. Temperature–salinity relationships, based on rapid sampling throughout the estuary, often indicated conservative mixing between riverine and coastal waters. Turbidity–salinity relationships throughout the estuary were approximately linear for most of the lower salinity range (<30) although the relationships varied throughout a tidal cycle. At the highest salinities, in the lower 2·5 km of estuary, significantly enhanced turbidities occurred during strong, onshore swell-wave conditions. Near-mouth turbidities were very low (<5 ppm) at high-water (HW) when the swell-wave height was small (<0·3 m). There was no correlation between near-mouth turbidity at HW and tidal range, whereas the correlation between near-mouth turbidity and swell-wave height explained over 90% of the variance in near-mouth turbidity. The temporal trends in freshwater turbidity and freshwater inflow during the fieldwork period were fairly similar. A statistically significant relationship existed between these variables when freshwater turbidity was correlated against inflow 30 h earlier. A ‘ model ’ of turbidity, based on 5 days of inflows and used to hindcast turbidity from 14 days of inflows between 16–29 September, explained over 80% of the variance in freshwater turbidity. Therefore, inflow exerted a significant control on the fluvial turbidity. It appears that very fine-grained particles were responsible for the observed turbidity in the central and upper reaches of the Tweed. During the flood, in the presence of strong wave activity in the coastal zone, larger sediment was rapidly winnowed in the lower reaches, close to the mouth, whereas fine silt particles remained in suspension and reached the limit of saline intrusion. 相似文献
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伶仃洋河口横向环流 总被引：6，自引：4，他引：2
横向环流存在于大多数河口中,在河口的动量平衡和物质输运过程中起着重要的作用,其形成的机制众多。本文利用三维水动力模型EFDC(Environmental Fluid Dynamics Code),结合1989年和2002年的实测数据对伶仃洋河口进行研究,得到了伶仃洋河口在洪季和枯季时期不同的水动力和盐度分布结构。在文中选取了具有代表性的两个断面,针对洪枯季、大小潮以及涨落潮等不同时期的横向流结构和盐度剖面分布特点进行比较和分析。结果显示,受局地的径、潮流条件和地形约束影响,横向环流结构并不能充分形成,在不同的区域表现出截然不同的结构特点。伶仃洋河口横向环流主要是在径、潮流与地形三者之间的相互作用下形成的,不同的区域的形成机制存在差异。综合分析后,本文认为伶仃洋河口的横向环流在该区域的动力过程中相对较为次要。 相似文献
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基于椒江河口大、小潮期间水位、流速、盐度和悬沙浓度观测数据,研究了椒江河口主潮汐通道的水动力、盐度和悬沙浓度的时空变化特征,解释了高浊度强潮作用下的层化物理机制。椒江河口大潮期悬沙浓度和盐度均大于小潮期,主潮汐通道区域落潮期悬沙浓度大于涨潮期;盐度随潮变化,盐水锋面出现在S2测站,锋面附近出现最大浑浊带;自陆向海,悬沙浓度递减,盐度递增;随水深增加,悬沙浓度与盐度递增。Richardson数与混合参数显示,盐度和悬沙引起的层化现象,是随着潮汐的变化而变化,涨潮时的层化均强于落潮,小潮时的层化持续时间最长,区域更广。混合参数随潮周期变化,大潮期高于临界值1.0,小潮期低于临界值1.0。小潮期水体层化强于大潮期;潮汐应变项是影响势能差异变化率的重要因素;落潮期间层化向混合状态转化,涨潮相反。 相似文献
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河口是河流系统与海洋系统之间的界面,它首先是河流与海洋之间的物质界面。河流水体与海洋水体间最大的物质差异是盐分,因此,采用盐度作为河口界面的界定标准,将河口界面界定为盐度为0.5~30的由冲淡水控制的河口中心区域。在此基础上应用界面理论,分析了河口的渗透性和防御性及其动力、沉积、生物与地貌响应。借鉴Gilbert三角洲的动力分类方法,将河口界面按动力结构分为径流优势型、潮汐优势型、波浪优势型及其过渡类型。每一种河口界面又可细分为动力、沉积、地貌及生态等次一级界面。在珠江三角洲地区,磨刀门、蕉门河口等径流优势型河口界面主要承担泄洪任务,而虎门、崖门等潮汐优势型河口界面在纳潮能力上更有优势,其间通过河道支汊相互沟通和联系,形成了珠江河口界面的多层次结构。河口界面动力的复杂性,构成了河口界面形态和功能的复杂性。这些功能包括开发利用功能、生态功能、防洪功能和社会服务功能。河口管理的最高目标是河口的永续健康、结构和功能彼此协调,保持河口界面结构和功能的完整性。河口界面的复杂性对河口管理提出了更高的要求,要注重河口管理内容的综合性、问题的复杂性和管理效应的长周期性。针对珠江河口生境退化、海岸侵蚀、污染严重、咸潮活动加剧和口门淤积造成排水不畅等诸多问题,以及河口无序开发利用、管理体制混乱、公众参与少的管理现状,结合珠江河口界面整体、动态、彼此联系的特点,提出珠江河口管理"科学、和谐、安全和预警"的管理理念,由行政管理转变为服务管理,切实做好珠江河口管理工作。 相似文献
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Boron is found to be conservative in the Tamar Estuary in a series of surveys conducted over an 18-month period. Dissolved boron in the estuary derives almost entirely from seawater. 相似文献
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长江口水下高分辨率微地貌及运动特征 总被引：4，自引：1，他引：4
在 1997年枯季和 1998年全流域特大洪水后期 ,用旁侧声纳、热敏式双频测深仪、差分GPS、2 4道浅地层剖面仪、声学悬沙浓度剖面仪、流速仪等对长江口区主航槽进行走航测量和定点探测 ,第一次获得了长江口大量细颗粒大尺度底形沙波三维实测图像、数据以及底形运动的连续时间序列可视图像和数据。对这些图像和数据的分析结果对河口动力沉积和动力地貌过程、河口地形演变、大比例尺水下地形测量、三维流场的数值模拟、港口航道的疏浚以及深水航道的稳定性研究等具有重要意义。 相似文献
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Fish species diversity in the Huanghe Estuary 总被引：3，自引：0，他引：3
I~IOXThe Huanghe River is among the largest rivers in the world. It is the cradle of the ChineseciviliZation, and haS a great importance in fisheries. There were some studies on the HuangheRiver fisheries, such as the Repert of the Basic Fishery Biological Su~ of the Huanghai Riber(Anon, 1960), The Fishery Resources Of the Huanghe Riber System (Anon, 1986a). With regard to the fish species diversity in the Huanghe Estuary, there were only some general information from Read of Ichth… 相似文献
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The Bedload Movement in the Changjiang Estuary 总被引：6，自引：0，他引：6
- Sandwaves in the Changjiang estuary were measured with a shallow sediment profiler and an echosounder from 1978 to 1988. The data, together with grain size and bedform of sediment indicates that the bedload movement by rolling and saltation is of great significance to sediment transport and is the principal factor responsible for sandwave and sandbody development in the estuary. The sandwaves were found well-developed, which is related to the tidal range and the velocity of ebb current. However, the further growth is restricted by strong flood current prevailing in the estuary. Because of the significant bedload, the sandbodies shift obviously and frequently, and sometimes the exchange of position occurs between the sandbodies and tidal channels. As a result, ships are regularly forced to change their navigation course. 相似文献
19.
Christopher R Sherwood David A Jay R Bradford Harvey Peter Hamilton Charles A Simenstad 《Progress in Oceanography》1990,25(1-4)
Historical changes in the hydrology, sedimentology, and physical oceanography of the Columbia River Estuary have been evaluated with a combination of statistical, cartographic, and numerical-modelling techniques. Comparison of data digitized from US Coast and Geodetic Survey bathymetric surveys conducted in the periods 1867–1875, 1926–1937, and 1949–1958 reveals that large changes in the morphology of the estuary have been caused by navigational improvements (jetties, dredged channels, and pile dikes) and by the diking and filling of much of the wetland area. Lesser changes are attributable to natural shoaling and erosion. There has been roughly a 15% decrease in tidal prism and a net accumulation of about 68 × 106m3 of sediment in the estuary. Large volumes of sediment have been eroded from the entrance region and deposited on the continental shelf and in the balance of the estuary, contributing to formation of new land. The bathymetric data indicate that, ignoring erosion at the entrance, 370 to 485 × 106m3 of sediment has been deposited in the estuary since 1868 at an average rate of about 0.5 cm y−1, roughly 5 times the rate at which sea level has fallen locally since the turn of the century.Riverflow data indicate that the seasonal flow cycle of the Columbia River has been significantly altered by regulation and diversion of water for irrigation. The greatest changes have occurred in the last thirty years. Flow variability over periods greater than a month has been significantly damped and the net discharge has been slightly reduced. These changes in riverflow are too recent to be reflected in the available in the available bathymetric data.Results from a laterally averaged, multiple-channel, two-dimensional numerical flow model (described in Hamilton, 1990) suggest that the changes in morphology and riverflow have reduced mixing, increased stratification, altered the response to fortnightly (neap-spring) changes in tidal forcing, and decreased the salinity intrusion length and the transport of salt into the estuary.The overall effects of human intervention in the physical processes of the Columbia River Estuary (i.e. decrease in freshwater inflow, tidal prism, and mixing; increase in flushing time and fine sediment deposition, and net accumulation of sediment) are qualitatively similar to those observed in less energetic and more obviously altered estuarine systems. A concurrent reduction in wetland habitats has resulted in an estimated 82% reduction in emergent plant production and a 15% reduction in benthic macroalgae production, a combined production loss of 51,675 metric tons of organic carbon per year. This has been at least partially compensated by a large increase in the supply of riverine detritus derived from freshwater phytoplankton primary production. Comparison of modern and estimated preregulation organic carbon budgets for the estuary indicates a shift from a food web based on comparatively refractory macrodetritus derived from emergent vegetation to one involving more labile microdetritus derived from allochthonous phytoplankton. The shift has been driven by human-induced changes to the physical environment of the estuary.While this is a relatively comprehensive study of historical physical changes, it is incomplete in that the sediment budget is still uncertain. More precise quantification of the modern estuarine sediment budget will require both a better understanding of the fluvial input and dredging export terms and a sediment tranport model designed to explain historical changes in the sediment budget. Oceanographic studies to better determine the mechanisms leading to the formation of the turbidity maximum are also needed. The combination of cartography and modelling used in this study should be applicable in other systems where large changes in morphology have occurred in historical time. 相似文献
20.
涨潮槽是河口重要的地貌类型，其潮汐动力受地形摩擦、径流及风浪等因素影响而发生不对称现象，直接影响槽内
的泥沙动力过程。本文基于实测数据与数值模型计算潮汐不对称偏度，研究长江口南支最大的涨潮槽———新桥水道的潮汐不
对称性及其影响因素。结果表明：（!） 受余流与各分潮的相互作用控制，新桥水道可分为三个区域，上段为涨潮优势区域，
中段为涨落潮转换区域，下段是落潮优势区域。（"） 新桥水道欧拉余流表现出明显的分段差异，上段指向陆而在中下段指向
海并受到径流影响。斯托克斯余流则均指向陆并向陆增强。（''） 新桥水道内中下段潮汐不对称受地形的影响较大，其中扁担
沙的北移增强了新桥水道中段的涨潮优势特性，新的新桥通道的形成促进了新桥水道下段的落潮优势特性。 相似文献