黄河清水沟流路稳定性分析

根据１９８９年５月和８月枯、洪水两个季节黄河拦门沙区及河口海区地质和水文调查资料，结合黄河利津水文站近几年的径流量和输沙量变化，对黄河清水沟流路稳定性及其影响因素进行综合分析研究。结果表明，近年来黄河来沙量渐少是清水沟流路稳定的重要因素之一，随着河口向南转向海动力作用较弱的莱州湾，海水沿河上溯力逐渐减弱，河流泥沙得以更顺利入海，并在口门外沉积；现流路河口海域的水动力作用虽然较弱，但涨，落潮流的分布     

Temporal and spatial distributions of contaminants in sediments of Santa Monica Bay,California

Contaminant inputs from wastewater discharge, a major source of contamination to Santa Monica Bay (SMB), have declined drastically during the last three decades as a result of improved treatment processes and better source control. To assess the concomitant temporal changes in the SMB sediments, a study was initiated in June 1997, in which 25 box cores were collected using a stratified random sampling design. Five sediment strata corresponding to the time intervals of 1890-1920, 1932-1963, 1965-1979, 1979-1989, and 1989-1997 were identified using (210)Pb dating techniques. Samples from each stratum were analyzed for metals, 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites (DDTs), polychlorinated biphenyls (PCBs), and total organic carbon (TOC). Samples from the 1965-1979, 1979-1989, and 1989-1997 strata were also analyzed for polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs). Sediment metal concentrations increased from 1890-1979 and were similar during the time intervals of 1965-1979, 1979-1989, and 1989-1997, although the mass emissions of trace metals from sewage inputs declined substantially during the same time period. Trace organic contamination in SMB was generally highest in sediments corresponding to deposition during the years of 1965-1979 or 1979-1989 and showed a decline in concentration in the 1989-1997 stratum. Temporal trends of contamination were greatest in sediments collected from areas near the Hyperion Treatment Plant (HTP) outfall system and on the slope of Redondo Canyon. The highest contaminant concentrations were present in sediments near the HTP 7-mile outfall in the 1965-1979 stratum. Elevated trace metal and organic concentrations were still present in the 1989-1997 stratum of most stations, suggesting that sediment contaminants have moved vertically in the sediment column since sludge discharges from the 7-mile outfall (a dominant source of contamination to the bay) ceased in 1987. The widespread distributions of DDTs and PCBs in SMB and highly confined distribution of LABs around the HTP outfall system were indicative of a dispersal mechanism remobilizing historically deposited contaminants to areas relatively remote from the point of discharge.     

鸭绿江河口地区沉积物的粒度变化及影响因素

通过对比鸭绿江河口不同地区柱状样的粒度参数及敏感组分变化规律,分析了河口不同地区沉积动力环境和沉积特征的差异;结合代表性柱状样的210Pb测年,分析了柱状样在不同时期自然和人类活动影响下的沉积特征变化。结果表明,西水道主要受潮流作用而含有泥沙互层,粒度参数变化小;西岸潮滩受潮流和波浪作用含有贝壳碎屑,并在顶部出现粗化层。近几十年来,鸭绿江河口地区沉积特征的变化主要由于人类活动对水沙入海通量的影响:1941年以前柱状样的波动沉积特征反映了河流山溪性特征;1941—1970(1980)年随水沙入海通量减少而呈现砂含量降低、粉砂增加的特征;1970(1980)—1990年由于水沙入海通量变化较小,而呈现沉积物组成和敏感组分保持稳定的特征;但1990年后随水沙入海通量的进一步降低,邻近河口区域的沉积物出现明显的粗化。     

黄河入海口壬基酚污染分布特征

黄河口表、底层水体和沉积物中壬基酚的浓度分布特征研究结果表明,表层水体中壬基酚浓度为15.7~148.6 ng/L,平均值为47.5 ng/L;底层水体中壬基酚浓度为15.8~52.7ng/L,平均值为31.0 ng/L;表层沉积物中壬基酚浓度为2.31~5.47 ng/g,平均浓度为3.87ng/g。黄河口水体中壬基酚浓度呈现由河道向出海口外逐渐降低的趋势;河道中表层沉积物壬基酚含量高于出海口外。黄河口水体中壬基酚浓度低于文献中报道的海河口水体中的浓度,表层沉积物中壬基酚含量低于珠江口文献报道值。水体中壬基酚浓度超过抑制藤壶附着浓度(10 ng/L),河道最上游的站点水体中的浓度超过影响太平洋牡蛎幼苗的发育并增加幼苗死亡率的浓度(100 ng/L)。     

Geochemical signature as paleoenvironmental markers in Holocene sediments of the Tinto River estuary (Southwestern Spain)

High absolute concentrations of metals associated to sulfide deposits located at the river source (Fe, Cu, Zn, Pb, Cd, and As) have been determined from the study of major and trace element concentrations in sediment samples obtained in two vibracores in the Tinto River estuary. In most cases, the enrichment factor (EF) for these metals is over 2. Cu, Zn and As have much higher EF, over 10 in surficial samples. Fe oxy-hydroxide precipitation in high-chlorinity zones and its scavenging effect on metals is the main control process on the chemical composition of sediment. Vertical evolution of the sedimentary and geochemical characteristics of the cores show that the estuary has undergone a process of progressive shallowness and a relative increase in acidic river water volume with respect to seawater. This effect has originated a downstream displacement of acid mixing processes affecting the estuary, which is reflected in higher metal concentrations in sediments of the outer zones of the system.     

Growth of estuarine fish is associated with the combined concentration of sediment contaminants and shows no adaptation or acclimation to past conditions

We tested whether the growth rates of small benthic fish (Gillichthys mirabilis) in three southern California estuaries corresponded with the local concentrations of contaminants. Fish originating from each estuary were transplanted to cages in each estuary in two reciprocal transplant experiments. The growth rates of caged fish, and the size-distribution of natural populations, showed the same pattern of difference among estuaries. Twelve metals and organic contaminants occurred in bulk sediments at concentrations close to their individual ERL values, and a simple index of their combined concentration (the mean ERL quotient) was inversely correlated to the growth of caged fish. Metals in the water column occurred at lower concentrations, relative to toxicity thresholds, than those in sediments and were unrelated to fish growth. Fish used in the field caging experiments, and other fish held in the laboratory under constant conditions, showed no difference in growth according to their estuary of origin. Fish originating from different estuaries also showed no consistent differences in their tissue burden of organic contaminants. Our results thus suggested no genetic adaptation or physiological acclimation to the past contaminant regime, but revealed a possible association between fish growth rates and the combined concentration of multiple sediment contaminants.     

珠江口河流输沙、河口沉积与粒度信息之间的联系

河口三角洲地区泥沙供应充分，是现代沉积速率较高的区域。快速沉积的泥沙包含高分辨率的环境信息。采用放射性同位素测年方法研究了珠江口伶仃洋大铲湾海域6个柱样的现代沉积速率，以2mm的间隔分析了其中2个柱样上部的粒度，并对其平均粒径和珠江流域的年输沙量进行了快速傅里叶变换，以期获取河流泥沙供应、河口沉积速率和沉积物垂向粒度变化的对应关系。结果表明，大铲湾海域的沉积速率为1～3cm／a，受动力条件和泥沙供应条件的影响显著。2个柱样的平均粒径的最显著重现周期与珠江年输沙量的周期性有较好的对应关系，并可能反映了季节的、年的和多年的沉积速率信息。对于每年沉积厚度在厘米级的环境，以毫米级的高分辨率进行粒度分析，有可能揭示出沉积物供应的季节变化和年际变化。本研究亦可为其他河口的相关工作提供借鉴。     

有机污染物在不同沿海沉积环境中积累的差异性

以浙江沿海水域为研究区域,在系统地测定水体与沉积物中有机污染物种类的基础上,研究了表层沉积物中有机污染物的积累与沉积环境、沉积物矿物组成和排放环境因素之间的相互关系.结果显示,沿海水体和表层沉积物中主要存在的有机污染物有石油烷烃类化合物、邻苯二甲酸酯化合物、有机硅氧链类化合物、氯代苯酚类、苯醚类和胺类化合物等6大类,它们在表层沉积物中的积累强度呈现出河口大于沿岸大于强潮汐河沉积环境的趋势,但在相同沉积环境的沉积物中有机污染物的积累强度存在一定的差异,这说明有机污染物在沿海沉积物中的积累除与沉积环境有关外,还与区域有机污染物的排放特点有关.     

Nereis diversicolor: an Unreliable Biomonitor of Metal Contamination in the 'Ría de Bilbao' (Spain)

Abstract. Samples of the polychaete Nereis diversicolor O.F. M üller and surficial sediments from a clean and a polluted estuary were taken during a year at monthly intervals to determine, by comparison, the range of temporal fluctuations in trace metal concentrations. Whereas metal variations in surficial sediments were more pronounced in the polluted estuary, concentrations in N. diversicolor in both estuaries showed a wide range of temporal variation that surpassed that of surficial sediments. A clear decline in all metals studied (except Mn) from polluted sediments was noted after episodes of strong rainfall. In the reference estuary the fluctuations were less pronounced. Metal body burdens in N. diversicolor from the two estuaries were usually quite similar even though total levels in sediments differed considerably, indicating a lack of worm-sediment relationship. The low level of Cu, Cr and Pb in the tissues of N. diversicolor suggest a mechanism which prevents the polychaete from being exposed to these metals in highly polluted sediments. Therefore, it is concluded that N. diversicolor cannot be considered to be an ideal biomonitor of metal contamination in the polluted Bilbao Estuary.     

Composition and fluxes of particulate organic matter in a temperate estuary (Winyah Bay, South Carolina, USA) under contrasting physical forcings

To understand the role that physical processes play on the biogeochemical cycles of estuaries, we conducted intense field studies of the turbidity maximum region within a partially mixed estuary (Winyah Bay, SC, USA) under contrasting conditions of river discharge, tides and wind. Water samples and hydrographic data were collected at different depths and locations along the main channel over several tidal cycles during several cruises to Winyah Bay. Tidal variations in current speed, salinity, total suspended solid concentrations were measured within each cruise and were consistent with estuarine circulation processes. Salinity and total suspended solid concentrations ranged from 0 to 32 and from 20 to over 500 mg L⁻¹, respectively, with the highest salinity and total suspended solid values measured during periods of low river discharge. In fact, comparison of tidally averaged salinity and total suspended solid concentrations revealed marked differences among cruises that were negatively correlated to river discharge and SW wind speed. Moreover, significant contrasts in the chemical compositions of suspended particles were evident among periods of contrasting river discharge and wind regime. For example, the weight percent organic carbon content of suspended particles ranged from 1 to over 6% and displayed a positive correlation with river discharge. Similarly, both the molar carbon to nitrogen ratios (10 to 20 mol:mol) and stable carbon isotopic compositions (−25 to −29%) of the suspended organic matter varied significantly as a function of discharge and wind. Such trends indicate that in Winyah Bay low river discharge and steady SW winds promote resuspension of bed sediments from shallow regions of the estuary. These materials contain highly altered organic matter and their incorporation into the water column leads to the observed trends in suspended particle concentrations and compositions. Furthermore, these conditions result in net landward fluxes of salt, sediment and particulate organic matter throughout most of the water column, promoting efficient trapping of materials within the estuary. Our results illustrate the fundamental connection between physical forcings, such as discharge and wind, sediment transport processes and the cycling of biogeochemical materials in estuarine environments.     

Trace metals and hydrocarbons in sediments from the Southampton water region,with particular reference to the influence of oil refinery effluent

The concentrations of a number of trace metals (Co, Ni, Cu, Zn, Ag, Cd and Hg) have been determined in sediments from cores collected in the Southampton Water region. Measurements of total hydrocarbons were also made on several of the cores. Markedly elevated concentrations of copper, up to 362 μg/g dry wt, were found in sediments which were collected close to the discharge points of oil refinery outfalls and which also showed concentrations of total hydrocarbons considerably greater than the background levels for the estuary. The results of selective chemical extractions showed that much of the copper was present in the non-lattice fraction of the sediment. Although the concentrations of Co, Ni, Zn and Cd were significantly correlated with those of copper in the core showing the highest concentrations of this element, these metals were not enhanced in comparison with the levels found in several other parts of the estuary. Variations in concentrations of metals in sediments throughout the estuary were not correlated with differences in organic carbon content.     

Estuarine sediment transport by gravity-driven movement of the nepheloid layer, Long Island Sound

Interpretation of sidescan-sonar imagery provides evidence that down-slope gravity-driven movement of the nepheloid layer constitutes an important mode of transporting sediment into the basins of north-central Long Island Sound, a major US East Coast estuary. In the Western Basin, this transport mechanism has formed dendritic drainage systems characterized by branching patterns of low backscatter on the seafloor that exceed 7.4 km in length and progressively widen down-slope, reaching widths of over 0.6 km at their southern distal ends. Although much smaller, dendritic patterns of similar morphology are also present in the northwestern part of the Central Basin. Because many contaminants display affinities for adsorption onto fine-grained sediments, and because the Sound is affected by seasonal hypoxia, mechanisms and dispersal pathways by which inorganic and organic sediments are remobilized and transported impact the eventual fate of the contaminants and environmental health of the estuary.     

工业化以来海洋污染历史的分子（元素）地层学记录

本文介绍了运用高分辨率的分子（元素）地层学记录来研究海洋污染历史的原理和方法。通过实例,阐述了利用放射性同位素２１０Ｐｂ等定年的湖泊、河口沉积物以及冰芯、土壤记录来研究环境污染历史的最新进展,指出对近百年来高时间分辨率的近海海域污染历史研究对于评估海域环境负荷变化,预测海洋环境的发展具有十分重要的意义。     

Grain size trend and hydrodynamic condition of tirumalairajan River estuary,east coast of India

The estuary can be considered as environments characterized by high productivity and uncommensurable ecological value. However, marine ecosystems are also subjected to high human pressures that increase their vulnerability. The aim of this work is to analyze grain size trend of sediment due to the action of the main hydrodynamic condition. The spatial distribution patterns of sediments were monitored according to season. The grain-size trend of surficial sediments revealed a dominant sediment transport trend towards the eastern and south eastern part of study area. This study shows that there is an agreement among sediments path ways, hydrodynamic condition and the sediment spatial distribution in the estuarine environment. The agitation by waves is an important sorting mechanism in the study area. The findings are based on the grain size trend and also corroborated by short term observations of the estuarine sediment dynamics and transport during the monsoon, postmonsoon, summer and premonson seasons in Tirumalairajan River estuary.     

Selenium in sediments, pore waters and benthic infauna of Lake Macquarie, New South Wales, Australia

Measurements of selenium in sediments and benthic infauna of Lake Macquarie, an estuary on the east coast of Australia, indicate that sediments are a significant source of selenium in the lake's food web. Analysis of surficial sediment samples indicated higher selenium concentrations near what are believed to be the main industrial sources of selenium to the lake: a smelter and a power station. Sediment cores taken from sediments in Mannering Bay, near a power station at Vales Point, contained an average of 12 times more selenium in surficial sections than sediment cores from Nord's Wharf, a part of the lake remote from direct inputs of selenium. The highest selenium concentration found in Mannering Bay sediments (17.2 μg/g) was 69 times the apparent background concentration at Nord's Wharf (0.25 μg/g). Pore water concentrations in Mannering Bay were also high, up to 5 μg/l compared to those at Nord's Wharf which were below detection limits (0.2 μg/l). Selenium concentrations in muscle tissues of three benthic-feeding fish species (Mugil cephalus, Platycephalus fuscus, Acanthopagrus australis) were significantly correlated (p<0.05) with surficial sediment selenium concentration. Selenium concentrations in polychaetes and molluscs of Mannering Bay were up to 58 times higher than those from Nord's Wharf. Two benthic organisms, the eunicid polychaete Marphysa sanguinea and the bivalve mollusc Spisula trigonella, were maintained at different densities in selenium-spiked sediments. Both animals accumulated selenium from the spiked sediment, confirming that bioaccumulation from contaminated sediments occurs. Collectively, these data suggest that benthic food webs are important sources of selenium to the fish of Lake Macquarie.     

黄河贯通时间的新探索

石化2井钻孔的元素地球化学研究表明，现代黄河三角洲地区元素组成具有明显的规律性，与现代黄河沉积物元素组成相比，埋深233m之上的沉积物中大多数元素含量及元素之比与之接近，而233m之下的沉积物元素组成则明显偏离黄河物质的化学组成。上部与下部沉积物的元素组成明显不同。差别函数及物源指数计算结合岩性、粒度分析揭示，黄河物质在该地区的影响深度可达233m左右，因此，推测大致在早更新世时黄河贯通并流进华北平原的现代黄河三角洲地区。     

珠江磨刀门河口底质沉积特征及其泥沙运移趋势

根据珠江磨刀门河口的表层沉积物粒度分析结果,运用Gao-Collins粒径趋势分析方法(GSTA模型),计算河口的沉积物净输运趋势,并分析河口底质沉积特征。结果表明:河口较粗的沉积物分布在交杯沙浅滩和拦门沙顶部,受波浪作用影响分选较好;磨刀门主槽、龙屎窟和口外海滨的沉积物则较细,以粉砂和粘土为主,分选稍差。沉积物在纵向和横向上都表现出细-粗-细的变化趋势。磨刀门主槽泥沙受强径流影响,具有向南的输运趋势;龙屎窟在涨潮流作用下,泥沙净向北输运;在西向沿岸流和东南向浪作用下,拦门沙东侧浅滩泥沙向西侧搬运,口外海滨的泥沙输运趋势则向北。     

厦门湾及邻近海域沉积物分布特征和沉积速率

2007年和2010年在厦门湾及邻近海域进行底质表层沉积物和柱状岩心样品采集,并进行粒度分析及粒度参数计算,获得了研究区底质表层和柱状沉积物样品的粒度分布特征.结果表明,厦门湾海域沉积物类型多样,以粉砂质砂和砂质粉砂为主.平均粒径介于?1.5Φ~7.5Φ之间.采用 Gao-Collins粒径趋势分析方法,发现九龙江口的沉积物主要呈东南方向净输运,而大金门南侧海域沉积物则有向九龙江口输运的趋势,同安湾内沉积物由海岸向湾中央输运;厦门东部海域沉积物向北输运,翔安南部海域沉积物向同安湾口以及澳头近岸输移.对柱状岩心进行放射性同位素210Pb 测年分析,计算得到九龙江口沉积速率为2.62 cm/a,进而探讨了九龙江口的沉积环境演化特征,研究成果可为区域资源开发和环境保护提供科学依据     

Sediments in the East China Sea

This paper describes measurements of sediments during the 2000-2001 Asian Seas International Acoustic Experiment in the East China Sea. A number of techniques were used to infer properties of these sediments, including gravity and piston cores, subbottom profiling using a water gun, long-range sediment tomography, and in situ measurement of conductivity. Historical data from echosounder records and cores showed two regions of surficial sediments in the experimental area: a silty area to the west and a sandy area to the east. The tomography, cores, and water-gun measurements confirm the two surficial sediment regions seen in the historical data and also indicate that the subbottom structure at the experimental site consists of a thin (0-3 m thick) layer of sandy sediment directly beneath the sea floor. Below this layer, there is an extensive package of sediment with relatively uniform acoustic attributes. Core analysis shows that the surface sediment layer varies in compressional wave speed from a low near 1600 m/s in the west side of the experiment area to 1660 m/s in the east side of the experiment area. Long-range sediment tomography inversions show a similar spatial variation in the surface layer properties. In addition, the layer thickness as determined from tomography is consistent with the estimates from subbottom profiling.     

长江河口潮波传播机制及阈值效应分析

河口潮波传播过程受沿程地形(如河宽辐聚、水深变化)及上游径流等诸多因素影响,时空变化复杂。径潮动力非线性相互作用研究有利于揭示河口潮波传播的动力学机制,对河口区水资源高效开发利用具有重要指导意义。本文基于2007—2009年长江河口沿程天生港、江阴、镇江、南京、马鞍山、芜湖的逐日高、低潮位数据及大通站日均流量数据,统计分析不同河段潮波衰减率与余水位坡度随流量的变化特征,结果表明潮波衰减率绝对值与余水位坡度随流量增大并不是单调递增,而是存在一个阈值流量和区域,对应潮波衰减效应的极大值。为揭示这一阈值现象,采用一维水动力解析模型对研究河段的潮波传播过程进行模拟。结果表明,潮波传播的阈值现象主要是由于洪季上游回水作用随流量加强,余水位及水深增大,导致河口辐聚程度减小,而余水位坡度为适应河口形状变化亦有所减小,从而形成相对应的阈值流量和区域。