潮汐驱动下的辽东湾水动力及入海污染物输移特征

通过建立水动力学模型、物质输运模型和年龄模型,对渤海辽东湾潮汐驱动下的水动力状况和污染物输移扩散过程进行了数值模拟研究。结果表明,辽东湾海域入海径流对辽东湾整体流场和水交换过程影响不大,其主要影响集中在河口附近海域。在潮汐的驱动下,辽东湾内形成了复杂的环流结构,辽东湾南北海域分别存在顺时针、逆时针的环流,而辽东湾湾口又存在逆时针环流,使得水交换能力较弱,对辽东湾向外海的物质输运产生不利影响,湾顶附近海域的物质主要通过扩散过程与外海进行交换。年龄模型的计算结果表明,辽东湾河流入海污染物在河口附近停留时间较长,向远区的输运需要较长时间。入海污染物的影响具有局地性,对局部海域水质尤其是辽东湾湾顶的水质会产生不利影响。     

A three-dimensional numerical model of hydrodynamics and water quality in Hakata Bay

The hydrodynamics and water quality in Hakata Bay, Japan, are strongly affected by the seasonal variations in both the gravitational circulation and the stratification in the bay. The three-dimensional hydrodynamics and water quality model has been developed to simulate the long-term transport and fate of pollutants in the system. The model is unique in that it completely integrates the refined modelling of the hydrodynamics, biochemical reactions and the ecosystem in the coastal areas. It is a 3-dimensional segmented model which is capable of resolving mean daily variations in all the parameters relevant to pollution control. It predicts daily fluctuations in the oxygen content at different depths in water throughout the year. It takes into account transport and settling of pollutant particles. It predicts light penetration from computed turbidity variations. It includes interactions between the ecosystem and water quality, through nutrient cycling and photosynthesis. The model has been calibrated well against the data set of historical water quality observations in Hakata Bay.     

厦门浔江海域污染扩散数值模拟

本文采用ＡＤＩ活动边界潮流数值模拟模拟了厦门浔江海域的潮流，计算的结果与实测数据比较吻合。文中用欧拉污染扩散数值模型计算了从同安、集美、五通口排出的污染物（ＣＯＤ）对浔江海域的影响，同时采用拉格朗日污染扩散数值模型研究在湾口、集美和在北部的湾顶污染物瞬时排放后的运移情况。     

Numerical simulation of Pacific water intrusions into Otsuchi Bay,northeast of Japan,with a nested-grid OGCM

A numerical simulation of Otsuchi Bay located on the northeast coast of the Honshu, the largest island of Japan, is conducted, using an ocean general circulation model (OGCM) with a nested-grid system in order to illustrate seasonal variability of the circulation in the bay. Through a year, an anticlockwise circulation is dominant in the bay, as observational studies have implied, although it is modified in the bay-mouth-half of the bay in winter. In addition, there is an intense outflow at the surface layer during spring to autumn, influenced by river water discharge. Intrusion of the Pacific water into the bay is influened by mean circulations, but it is also influenced by baroclinic tides from spring to autumn. Pacific water intrusions affected by baroclinic tides may have an impact on the environment in Otsuchi Bay.     

Determining the age of water and long-term transport timescale of the Chesapeake Bay

The concept of age of water (AW) is applied to the Chesapeake Bay to investigate the long-term transport properties for dissolved substances. A real-time calibrated hydrodynamic Chesapeake Bay model in 3 Dimensions (CH3D), employing a boundary-fitted curvilinear grid, is used for the study. The long-term transport properties, represented by AW, are investigated under the conditions of low river inflow of 1995 and high river inflow of 1996, as well as for constant mean inflows. The influences of freshwater, density-induced circulation, and wind-induced transport on age distribution have been investigated. Model results show that river inflows, wind stress, and density-induced circulation play important roles in controlling the long-term transport in the Bay. The model results shows that it requires 120–300 days for a marked change in the characteristics of the pollutant source discharged into the Bay from the Susquehanna River to affect significantly the conditions near the mouth under different hydrodynamic conditions. An increase of river discharge results in increases of downstream residual current and gravitational circulation, and thus reduces AW. The density-induced circulation contributes to the transport substantially. The dissolved substances discharged into the Bay are transported out of the Bay more rapidly when the estuary becomes more stratified. Southeasterly and southwesterly winds have strong impacts on the transport compared to the northeasterly and northwesterly winds. The former increases lateral and vertical mixing significantly. Consequently, the gravitational circulation is reduced and the transport time is increased by 50%. The model results provide useful information for understanding the long-term transport processes in the Bay.     

湾口建闸海湾水体交换及景观水位数值模拟

大幅度的潮位变动对近岸景观和亲水性有较大影响,为此往往在湾口建闸控制湾内潮位变动,通过设置景观水位改善以上问题,但这将带来湾内的水动力及水体交换条件下降。本研究以马銮湾为例通过潮流数学模型模拟,研究湾口开闸孔数、开闸位置及不同景观水位与湾内水动力和水体交换的关系。利用湾口闸门调度,在湾内形成大尺度环流提高水体交换效率,对马銮湾景观水位和闸门调度方式提出了建议,有效地解决了湾内潮差减小引起水体交换效率减低的问题。     

Numerical experiments on wind-driven circulations and associated transport processes in Suruga Bay

The dynamics of the wind-driven circulations and surface transport processes in Suruga Bay have been examined by performing numerical experiments. While strong winds exist outside the bay, the winds inside the bays are greatly reduced, which generates a strong wind stress curl in winter and autumn. In particular, in winter, a strong positive curl region is located across the bay mouth, and a strong surface circulation with counterclockwise rotation is generated beneath it. The circulation is nearly geostrophic, but is not affected by the bottom topography in the deep bay. It is suggested that intense surface water exchange through the bay mouth occurs in winter, whereas it is not active in the other seasons when no significant vorticity is supplied on the bay mouth from the atmosphere. Moreover, we propose a hypothesis that the atmospheric wind stress curl will cause the frequent appearance of the counterclockwise circulation in winter in the real ocean.     

象山港水交换特性研究

在验证良好的三维斜压潮流数学模型的基础上,以溶 解态的保守性物质为示踪剂,建立对流-扩散型的海湾水交换数值模型,计算了象山港水体半交换时间和平均滞留时间,并研究了斜压动力对湾内外水交换的贡献。研究结果表明,象山港水交换速度的区域性变化较大,水体半交换时间和平均滞留时间由象山港口门向湾顶逐渐增加,口门附近半交换时间在5d以内,平均滞留时间为5~10 d;湾顶水交换速度缓慢,水体半交换时间为30~35 d,平均滞留时间为35~40d。斜压动力对狭湾外段水交换影响较弱,对狭湾内段有较大的影响。     

Sediment characteristics and water circulation of Big Jemsa Bay,Red Sea,Egypt

Big Jemsa Bay is one of the indentations dissecting the continuity of the Red Sea north-western shoreline. The data was collected from bathymetric survey, current meters and sediment samples. Analyses have been undertaken of coastal processes, seabed morphology, grain size characteristics and the effect of current circulation on the distribution of sediment characteristics. The sediment pattern varies from coarse sand in the southern part to silt and fine sand in the northern part. The central part of the study area is mainly composed of terrigenous isometric-medium sand facies. The sorting distribution of sediments varies from moderately well sorted to poorly sort. The significant factors that control the sediment transport process are downslope gravity and wave-induced currents that are affected by the seafloor configuration and the shoreline orientation. According to the circulation effect on the sediment transport of the study area where deposition of fine sand and silt was observed in the northern part. Because sediment transport mitigates the occurrence of pollutant deposition in this part of the bay, we recommend that future constructions along the bay should be in the southern part.     

Effects of oilfield brine effluent on sediments and benthic organisms in trinity bay,Texas

Field studies have established the concentrations of naphthalenes in bay sediments and water in the vicinity of an oil separator platform and their effects on the benthic fauna. Fifteen stations were occupied monthly, from July, 1974 to December, 1975, along three transects extending from the separator platform outfall outwards for a distance of 4·0 to 5·6 km. A lesser number of stations were occupied from April, 1974 to June, 1974. Bottom sediments at each station were analysed for total naphthalenes content and for number of species and individuals. All stations were located in 2 to 3 m of water. The outfall was located 1 m off the bay bottom.There was a definite correlation between sediment naphthalenes concentration and number of species and individuals. As expected, the first station, located 15 m from the outfall, had the highest concentration of naphthalenes of all stations sampled. The naphthalenes levels dropped sharply from the outfall to the stations located 75 m from the platform where levels were about 20–50% of those found 15 m from the outfall. Naphthalenes concentrations then decreased gradually to near background levels at stations farther out. Hydrocarbon concentrations in bottom water 15 m from the outfall were three orders of magnitude lower than those in the full strength effluent, but sediments 15 m from the outfall had hydrocarbon concentrations four times as great as in the full strength effluent. There were approximately four orders of magnitude more hydrocarbons in the sediment than in the overlying water.The bay bottom was almost completely devoid of organisms within 15 m of the effluent outfall. Stations located 150 m from the outfall had severely depressed benthic faunas but not to the extent of stations nearer the outfall. Stations located 455 m from the platform were unaffected. Both numbers of species and individuals increased with distance from the platform and reached a peak at the first station medial to the control on each transect (685 to 1675 m from the platform) and then dropped at the control station. Physical environmental factors such as temperature, salinity, water depth and sediment type were essentially the same at all stations.The temporary use of a second outfall located 275 m from the main platform outfall resulted in a rapid build up of naphthalenes in surrounding sediments which persisted for at least six months following the termination of use of the second outfall. The benthic fauna was also severely depressed in the vicinity of the second outfall. The use of multiple outfalls, located some distance apart, appears to be more harmful than the use of a single outfall.Trinity Bay, Texas, the site of this investigation, has a mean depth of 2·5 m. The bay water is highly turbid due to the presence of a high concentration of clay-sized particulate material. The brine outfall was located approximately 1 m above the bay bottom. These special conditions undoubtedly contributed significantly to the observed impact of the brine. Therefore, extrapolations from the results of this study to offshore oil production and brine disposal should be made with extreme caution.     

钦州湾潮流特征分析

根据1994年5月和11—12月两个航次的调查及近年有关海湾的海流观测资料，分析了钦州湾的潮流特征，观测资料来自分布于该海湾东中西三个航道及相关区域的8个测站。钦州湾涨落潮流特征：落潮流速大于涨潮流速：东部最大涨落潮流速小于西部：夏季落潮流总是大于冬季：龙门水道附近的流速最大，而其余区域的流速相对较小。外湾(钦州湾)余流，是气旋式环流：水体东进而西出。从湾内来的泥沙和污染物质，主要从西部进入外海；中、东槽是主要“进水”通道，外海低泥沙含量、少污染物质的清洁水从这里潮流而上。因此，与西部相比，东部盐度高，水质清洁，底质重金属含量少。     

大亚湾的环境研究

大亚湾自然条件优越,生物资源丰富,是当前广东经济开发的“热点”。本文从生态环境的角度讨论大亚湾的环境质量问题,并指出今后大亚湾的经济开发应注意环境保护问题。     

波流耦合下保守污染物迁移扩散的模拟研究

基于三维潮流和谱波浪模型,以及输移扩散模型和拉格朗日粒子追踪模型,构建了波流耦合下保守污染物的迁移扩散模型。模型基于非结构化网格,对近岸复杂岸线有很好的拟合,可用于大范围波流耦合计算。运用所建的耦合模型研究了旅顺港内外的潮流变化、波生流场、保守污染物输移、粒子运动、以及新水道对湾内污染物迁移的影响,模拟的潮流场与实测数据吻合较好。结果表明:潮流会在湾内近湾口处形成一逆时针涡,波浪对湾内影响较小,但波生流会改变湾口流场分布;在湾内处于涡中的水体潮流自净能力较强,而湾中及湾底则较弱,SE向波浪会降低湾内水体的自净能力;新潮流通道的开挖,会显著改善水体的自净能力,尤其对湾底浅水区域作用明显。     

洋浦经济开发区污水排海总量控制

研究建立洋浦近岸海域岸界自适应网格变动边界的潮流模型及物质输运模型。对开发区提出的多种污水排海方案进行污水质点拉格朗日追踪、污水排海的水质预测及工程投资分析 ,推荐了最佳排污口位置 ,最后计算了污水最大排放量及 8种污染物控制指标排放总量 ,为洋浦开发区的环境管理与保护提供决策依据。     

Investigation of Fethiye-Marmaris Bay (SW Anatolia): seismic and morphologic evidences from the missing link between the Pliny Trench and the Fethiye-Burdur Fault Zone

New (2009) multi-beam bathymetric and previously published seismic reflection data from the NE-SW-oriented Fethiye Bay and the neighboring N-S-oriented Marmaris Bay off SW Anatolia were evaluated in order to interpret the seafloor morphology in terms of the currently still active regional tectonic setting. This area lies between the Pliny Trench, which constitutes the eastern sector of the subduction zone between the African and Eurasian plates in the Eastern Mediterranean, and the Fethiye-Burdur Fault Zone of the Anatolian Plate. The bathymetric data document the very narrow shelf of the Anatolian coast, a submarine plain between the island of Rhodes and Marmaris Bay, and a large canyon connecting the abyssal floor of the Rhodes Basin with Fethiye Bay. The latter are here referred to as the Marmaris Plain and Fethiye Canyon, respectively. Several active and inactive faults have been identified. Inactive faults (faults f1) delineate a buried basin beneath the Marmaris Plain, here referred to as the Marmaris Basin. Other faults that affect all stratigraphic units are interpreted as being active. Of these, the NE-SW-oriented Marmaris Fault Zone located on the Marmaris Plain is interpreted as a transtensional fault zone in the seismic and bathymetric data. The transtensional character of this fault zone and associated normal faults (faults f3) on the Marmaris Plain correlates well with the Fethiye-Burdur Fault Zone on land. Another important fault zone (f4) occurs along the Fethiye Canyon, forming the northeastern extension of the Pliny Trench. The transpressional character of faults f4 inferred from the seismic data is well correlated with the compressional structures along the Pliny Trench in the Rhodes Basin and its vicinity. These observations suggest that the Marmaris Fault Zone and faults f3 have evolved independently of faults f4. The evidence for this missing link between the Pliny Trench and the Fethiye-Burdur Fault Zone implies possible kinematic problems in this tectonic zone that deserve further detailed studies. Notably, several active channels and submarine landslides interpreted as having been triggered by ongoing faulting attest to substantial present-day sediment transport from the coast into the Rhodes Basin.     

Behavior of manganese in aqua-benthic environment in the Hiro Bay

The horizontal and vertical distributions of manganese in sea water, interstitial water and sediments in the Hiro Bay, Seto Inland Sea, Japan, have been investigated. The outflow from a pulp mill is the primary source of manganese in this bay. The industrial waste water contained 0.19 mg l^–1 of manganese, mostly in a dissolved form. This manganese diffused out both horizontally and vertically into the surrounding sea water. The content of manganese in the liquid and solid phases in the sediments, however, are inverse with that in the sea water; namely the lowest concentration of manganese in the sediments was observed at the station near the outfall and manganese concentration increased with the distance from the outfall.     

A Massive Coccolithophorid Bloom Observed in Mikawa Bay, Japan

In April 1996, a massive algal bloom of the coccolithophorid Gephyrocapsa oceanica developed in both Chita Bay and Atsumi Bay which comprise the bay known as Mikawa Bay of Japan. It was the first record of such a bloom in this area. In Chita Bay, the bloom persisted until the middle of May, however in Atsumi Bay, it remained until early June. From the analysis of salinity, water temperature, and current velocity and direction data, it is considered that the following mechanism accounts for the occurrence and maintenance of the bloom: Before the bloom, the standing crop of phytoplankton was poor, resulting in relatively rich nutrients throughout the bay. Thereafter, with the influx of oceanic water into Mikawa Bay, high salinity occurred firstly in Chita Bay. Under these hydrographic conditions, the bloom occurred first in Chita Bay, and extended throughout the bay with the clockwise circulation of water into Atsumi Bay. In Chita Bay, the bloom was influenced by rainfall and G. oceanica flowed out from this area. Whereas, in Atsumi Bay, the bloom persisted for longer due to the clockwise circulation and another influx of oceanic water.     

三沙湾夏季底边界层动力过程及悬沙输运特征

基于2018年8月福建三沙湾湾内外共两个定点站位的船基和座底三脚架观测数据,研究了三沙湾底边界动力过程及悬沙输运特征。结果表明,三沙湾湾内湾外两个站位均表现出涨落潮历时相近但涨落潮流速明显不对称的现象,即湾内涨潮流速大于落潮流速,湾外则相反。湾内水体受淡水输入影响较大,表现出落潮期间显著的温盐层化,而涨潮期间水体混合良好;湾外水体受淡水影响不明显,表现为水体温度主导的层化。通过对底边界层动力过程的分析表明,湾内（距底0.75 m）、湾外（距底0.50 m）站位底边界层的平均摩阻流速分别是0.016 m/s、0.013 m/s,且两个站位拖曳系数基本相等（2.03×10-3）,表明在相同流速下湾内站位的底部切应力更大,近底沉积物再悬浮和搬运相对湾外站位更为显著。因此观测期间悬沙浓度最大值出现在湾内站位,为109 mg/L,且悬沙在垂向上的分布可达上层水体;湾外站位悬沙浓度更低,并且底部悬浮泥沙仅能影响至距底5 m的水体。悬沙通量机制分解结果表明,三沙湾夏季的潮周期单宽悬沙从湾外向湾内方向净输运,湾内站位向湾内方向净输运74.88 g/(m·s),平流输沙占主导作用,贡献率41.7%;湾外站位向湾内方向净输运10.57 g/(m·s),主要受平流输沙和垂向净环流的控制,贡献率94.9%     

基于FVCOM 的辽东湾水动力特性数值模拟

辽东湾属于半封闭性海湾, 水动力过程具有一定的代表性。本文基于无结构化三角形网格的有限体积海岸海洋模型FVCOM（Finite-Volume Coastal Ocean Model）, 构建了辽东湾及其邻近海域的三维水动力数值模型, 并利用实测数据对6 个潮位验潮站、4 个潮流验潮站的大小潮时刻的潮位、流速、流向进行了对比验证, 该模型能够准确地模拟辽东湾的潮汐、潮流等水动力场情况, 可进一步为研究辽东湾温盐、泥沙、水质、污染物扩散等提供研究基础。     

基于FVCOM的廉州湾及周边海域三维潮汐潮流数值模拟(英文)

基于采用不规则三角网格和有限体积方法的FVCOM模式,建立廉州湾三维潮流数值模型来重现廉州湾及周边海域的潮位和潮流变化状况。根据模拟结果计算得到了较以往更为精细的廉州湾及周边海域K1、O1和M2分潮的同潮图,并计算了由此三个分潮引起的潮汐不对称的变化情况。K1和O1分潮在廉州湾外主要以驻波的形式存在,进入廉州湾后转化为前进波;M2分潮在廉州湾外主要以前进波的形式存在,进入廉州湾后前进波特征更为明显。K1和O1分潮流在廉州湾外以旋转流为主,在廉州湾内以往复流为主;M2分潮流在整个研究海域以往复流为主。由潮余流场的分布特点可以看出自南向北由外海进入廉州湾的潮余流,在冠头岭处分为两支,一支逆时针转向西,另一支被冠头岭阻挡在其南侧形成顺时针封闭环流。在廉州湾内部同时存在两个环流系统,湾顶的气旋式环流和口门处的反气旋式环流。