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本文利用台站观测、卫星遥感以及专项调查等多种数据,综合分析了近年来胶州湾典型水文气象要素的变化特征及建桥前后水动力环境等的变化对冬季冰情的影响。结果显示,建桥以来冰情较重的年份冬季气温和年最低气温均处于近30年的低位,重冰期与年最低气温时段相吻合,且以跨海大桥为界,北部海湾结冰现象严重,而南部几乎无结冰。基于区域海洋水动力模型(ECOM)的模拟结果显示,跨海大桥建设可以从几个方面影响胶州湾北部海冰的生消,即大桥建设使胶州湾尤其是大桥北侧的水动力环境弱化,落潮时桥北侧水体堆积,涨潮时桥北侧向陆一侧水位减小;大桥对桥位南北1.5 km周围涨、落潮流场产生影响;流场的变化又使得悬浮物对流扩散和沉积物输运发生改变,大桥北侧局部区域水深变浅。 相似文献
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在胶州湾湾口、西侧、中心、东侧、北侧湾顶五个区域布设测站,利用2018年冬季至2020年秋季潮位、海流等监测数据,基于最小二乘法进行调和分析计算,并结合垂线平均流速流向、可能最大流速、水质点可能最大运移距离等计算模型,研究分析了胶州湾海流特征。结果表明,各区域潮流类型系数均小于0.5,M2分潮椭圆率绝对值均不超过0.1,接近于0,故胶州湾潮流性质为正规半日潮流,潮流运动形式以往复型为主。湾口区域余流、可能最大流速、水质点可能最大运移位移均最大。不同季节余流流速和流向的差异没有明显的规律性,除湾区西侧测站外,其余位置不同季节余流流向整体上有固定朝向：湾口处东偏北、中心站西偏北、东侧站南偏东、北侧湾顶站东偏北。靠近岸边的湾口、东侧和北侧湾顶站余流流向与邻近海岸垂直。在垂直方向上,各测站可能最大流速和水质点可能最大运移距离由表层至底层整体上呈减小趋势,流向基本一致。 相似文献
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本研究通过对胶州湾大桥建成前后湾内泥沙冲淤情况进行模拟。探讨了典型时刻胶州湾大桥附近海域的海流流速和流向情况。对比胶州湾大桥建成前湾内的流场模拟结果可知,胶州湾大桥的建设对胶州湾内整体的海流流态影响较小。胶州湾大桥的建设对胶州湾水动力的改变主要在桥墩建设附近海域。通过大桥建设前后冲淤数值模拟结果可知,工程前后工程附近冲淤趋势基本一致,只是在大桥桥墩附近出现冲淤变化较大的情况,表现为在桥墩的南北两侧出现较大桥建设前淤积加强区,在桥墩的东西两侧出现冲刷加强区,在通航孔桥墩跨度较大的海域,冲刷强度增大比较明显。 相似文献
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大连湾保守污染物迁移三维模型及应用 总被引：1，自引：0，他引：1
采用基于有限体积法和非结构化网格的三维潮流模型,同时耦合拉格朗日粒子追踪模型和保守污染物输运扩散模
型。模拟了大连湾内的水动力变化、潮致余流场分布、保守污染物的输移和特征粒子的运动轨迹;同时研究了不同人工岛对
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：湾内潮致余流呈顺时针半涡形态,湾口潮致余流呈
NE 方向;湾内保守污染物主要随潮致余流的方向而迁移,湾口的迁移扩散快于湾中,湾内北部的污染物能较快扩散到湾外,
湾内南部的污染物易在湾底滞留,各个子湾内的污染物不宜扩散出来;两种方案人工岛均会降低臭水套湾和香水套湾的自净
能力,且方案2 比方案1 的影响大;而对红土堆子湾方案1的影响比方案2大,且方案2 能改善其水质情况。 相似文献
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为探讨长江口南港的水动力结构及悬沙侧向输运特征,本文从解析解的角度构建了潮汐河口水沙输运数学模型,并将其应用到长江口南港某横断面上。南港水动力主控于半日潮流,余流主要由陆相径流及本地非线性对流项驱动,悬沙分布上北侧副槽远大于南侧主槽,水沙分布的计算结果与实测结果在结构上基本一致。通过输沙函数进一步分析表明,潮流输沙和余流输沙是南港侧向输沙函数的两个主要部分。南港中强劲径流削弱了涨潮流,增强了落潮流,使得向河槽南侧的涨潮流输沙小于向河槽北侧的落潮流输沙,潮流输沙指向河槽北侧。径流驱动的南港侧向余流在涨潮流方向上为一逆时针环流结构,余流输沙指向河槽北侧。扩散输沙指向南侧主槽,因其总是指向悬沙浓度梯度的负方向。在各输沙因子的综合作用下,南港中大量悬沙捕集于河槽北侧,使得河槽北部底层潮平均含沙量值达到最大值。 相似文献
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为探究渤海岸线及水深变化对水动力的影响,基于Delft3D水动力学模型,选用2003年和2015年作为围
填海前后的典型年份,建立了围填海前后岸线及水深条件下的渤海三维水动力模型,并对水动力场进行了模拟。通过对围填海前后潮波和潮余流的分析,得到了岸线及水深变化对渤海水动力场的影响。结果表明:填海后,岸线及水深变化会对渤海主导分潮M2分潮产生较大影响,秦皇岛附近无潮点向西北方向偏移,渤海海域M2 分潮振幅总体减小;潮致余流场受岸线及水深变化影响较大,其中渤海湾曹妃甸港南部形成复杂的涡流,沿岸海域余流增大;滨海新区附近形成多个小范围环流,且天津港到黄骅港北部沿岸海域2015年余流比2003年增加3~5 cm/s;黄骅港南部形成一个逆时针环流,并且该处余流减小2~5 cm/s。辽东湾辽河口附近由于水深增加导致余流减小2~7 cm/s。莱州湾黄河口附近的逆时针环流向东南方向移动,黄河口北部余流略有减小,东南部余流明显增大,增加量最多能达到9 cm/s。刁龙嘴南侧顺时针环流减小,北侧顺时针环流增大4~9 cm/s。 相似文献
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《中国海洋大学学报(自然科学版)》2017,(3)
基于无结构网格三维有限体积海洋模式FVCOM,采用高精度的水深和岸线资料,建立了适用于胶州湾的三维正压高分辨率数值模型。通过观测与模拟资料的对比,验证了所建立模型的合理性。基于建立的模型,对胶州湾的潮汐潮流进行了精确的数值模拟,探讨了胶州湾潮致余流和纳潮量特征,并首次探讨了胶州湾内各子区域之间的水交换情况。结果表明,分别采用计算一个涨潮或落潮周期内通过特定断面的海水通量和研究区域的水深及水位值直接计算两种计算方法计算胶州湾的平均纳潮量,分别为8.90和8.71亿m~3,结果发现水位对纳潮量的影响最大可达1%以上,不可忽略;大潮时期的纳潮量为小潮时期的2~3倍;纳潮量春季最低,冬季其次,夏秋季较高。以质点追踪法,定量研究了胶州湾内各个子区域之间以及各子区域与外海的水交换情况。结果发现,胶州湾内不同子区域的水交换能力以及达到稳定时间均不同,且投放质点的时刻不同对其具有较明显影响。在涨潮时段,胶州湾西北部海域达到稳定时间较短且交换率高,东北部海域达到稳定时间较落潮时段基本不变但交换率高;落潮时段则相反。 相似文献
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胶州湾前湾填海对其水动力影响预测分析 总被引：5，自引：1，他引：4
本文采用ECOM-SED模式、算子分裂法和“干、湿”点法建立了胶州湾变边界数值模型。从潮、余流、潮波系统和潮流能几方面预测分析了胶州湾前湾追地对海洋水动力的影响。结果表明,前湾填海对胶州湾的潮波系统影响甚微,振幅和位相的变化都在1％以内。但是在前湾和工程附近海域潮流和余流变化比较大,其他海域的潮流和余流变化不大,潮流流速变化为1％左右,余流流速变化为3．14％～9．16％。填海后,内湾口和外湾口附近潮能通量增加2．6％～5．24％,前湾和工程局部区域潮能通量减小20．21％～87．23％。 相似文献
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金塘大桥跨越灰鳖洋,连接金塘岛沥港镇与宁波镇海新泓口,全长18.5 km,为舟山连岛工程的主体.该大桥工程所在海域潮汐为非正规浅海半日潮,历年最大潮差为3.67 m,多年平均潮差为1.91 m;潮流呈往复流特征,且基本平行于峡道走向.金塘大桥水域东侧微冲,西侧微淤,深泓摆幅较小,深槽稳定.在海床演变分析的基础上,运用数学模型进行了桥轴线的优化,由实体定床与动床模型探讨了建桥对水动力的影响.数学模型选用2002年3月和11月实测水文测验资料对模型进行率定和验证.物理模型选取中值粒径为0.2 mm的塑料沙作为动床试验的模型沙,选用2002年11月实测水文测验资料对定床模型进行验证,选用2002年11月和2003年4月两次水下地形资料对动床模型进行河床冲淤验证,验证精度均满足相关规范要求.研究结果表明,以推荐的方案建桥对桥位近区的潮位、流速与潮量的影响均较小.建桥后,下游高潮位有所抬高,上游高潮位有所降低;上游低潮位有所抬高,下游低潮位略有降低.由于桥墩的阻水作用,使该桥所在海域海流流速整体上略有减小,减小量一般在5%以内;桥墩间因海流集中使流速有所增加.建桥使主航道航深有所增加,桥位近区与远区分别冲刷0.6～0.8 m和0.1～0.2 m;西航道桥轴线近区冲刷0.4～0.5 m,远区淤积0.1～0.2 m.建桥对甬江口、金塘锚地、七里屿锚地均无明显的不良影响,对北仑港区基本没有影响. 相似文献
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Soil-sized particulates have been collected on board ship by a mesh technique from the lower troposphere of the North, Equatorial and South Atlantic Ocean, northern and southern Indian Ocean, South and East China Sea and various coastal localities.Spectrographic analysis reveals that, on average, the particulates have concentrations of Mn, Ni, Co, Ga, Cr, V, Ba, and Sr which are of the same order of magnitude as those in average crustal material. In contrast, the average concentrations of Pb, Sn, and Zn are one order of magnitude higher than those in average crustal material.Within this “world-wide” average there are significant geographical variations in the distributions of Pb, Sn, and Zn which may be related to anthropogenic sources.On the basis of trace-element distributions lower tropospheric soil-sized marine particulates have been divided into four genetic components; local, zonal, inter-zonal, and global. The proportions of these components vary geographically, and each component may have both a natural and an anthropogenic fraction. 相似文献
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Tautog, Tautoga onitis, is an abundant species of fish in estuaries of the northeastern United States. Planktonic tautog larvae are abundant in summer in these estuaries, but there is little information on rates of growth of tautog larvae feeding on natural assemblages of food in the plankton. We examined abundance and growth of larval tautog and environmental factors during weekly sampling at three sites along a nearshore‐to‐offshore transect in Buzzards Bay, Massachusetts, USA during summer 1994. This is the first study of a robust sample size (336 larvae) to estimate growth rates of field‐caught planktonic tautog larvae feeding on natural diets, using the otolith daily‐growth‐increment method. The study was over the entire summer period when tautog larvae were in the plankton. The sampling sites contrasted in several environmental variables including temperature, dissolved oxygen (DO), and chlorophyll a concentration. There was a temporal progression in the abundance of tautog larvae over the summer, in relation to location and temperature. Tautog larvae were first present nearshore, with a pronounced peak in abundance occurring at the nearshore sites during the last 2 weeks in June. Larvae were absent at this time further offshore. From late June through August, larval abundance progressively decreased nearshore, but increased offshore although never approaching the abundance levels observed at the nearshore sites. The distribution and abundance of tautog larvae appeared to be related to a nearshore‐to‐offshore seasonal warming trend and a nearshore decrease in DO. Otoliths from 336 larvae ranging from 2.3 to 7.7 mm standard length had otolith increment counts ranging from 0 to 19 increments. Growth of larval tautog was estimated at 0.23 mm·day?1, and length of larvae prior to first increment formation was estimated at 2.8 mm indicating that first increment formation occurs 3–4 days after hatching at 2.2 mm. Despite spatial and temporal differences in environmental factors, there were no significant differences in growth rates at any of three given sites over time, or between sites. Because larval presence only occurred at a narrow range of temperature (17–23.5 °C) and DO (6.5–9.3 mg·l?1), in situ differences in growth did not appear to be because of differences in larval distribution and abundance patterns relative to these parameters. 相似文献
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P.N. Froelich L.W. Kaul J.T. Byrd M.O. Andreae K.K. Roe 《Estuarine, Coastal and Shelf Science》1985,20(3):239-264
Concentrations of dissolved nutrients (NO3, PO4, Si), germanium species, arsenic species, tin, barium, dimethylsulfide and related parameters were measured along the salinity gradient in Charlotte Harbor. Phosphate enrichment from the phosphate industry on the Peace River promotes a productive diatom bloom near the river mouth where NO3 and Si are completely consumed. Inorganic germanium is completely depleted in this bloom by uptake into biogenic opal. The ratio taken up by diatoms is about 0·7 × 10?6, the same as that provided by the river flux, confirming that siliceous organisms incorporate germanium as an accidental trace replacement for silica. Monomethylgermanium and dimethylgermanium concentrations are undetectable in the Peace River, and increase linearly with increasing salinity to the seawater end of the bay, suggesting that these organogermanium species behave conservatively in estuaries, and are neither produced nor consumed during estuarine biogenic opal formation or dissolution. Inorganic arsenic displays slight removal in the bloom. Monomethylarsenic is produced both in the bloom and in mid-estuary, while dimethylarsenic is conservative in the bloom but produced in mid-estuary. The total production of methylarsenicals within the bay approximately balances the removal of inorganic arsenic, suggesting that most biological arsenic uptake in the estuary is biomethylated and released to the water column. Dimethylsulfide increases with increasing salinity in the estuary and shows evidence of removal, probably both by degassing and by microbial consumption. An input of DMS is observed in the central estuary. The behavior of total dissolvable tin shows no biological activity in the bloom or in mid-estuary, but does display a low-salinity input signal that parallels dissolved organic material, perhaps suggesting an association between tin and DOM. Barium displays dramatic input behavior at mid-salinities, probably due to slow release from clays deposited in the harbor after catastrophic phosphate slime spills into the Peace River. 相似文献
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E. Wolanski P. Colin J. Naithani E. Deleersnijder Y. Golbuu 《Estuarine, Coastal and Shelf Science》2004,60(4):705-716
Three years of temperature data along two transects extending to 90 m depth, at Palau, Micronesia, show twice-a-day thermocline vertical displacements of commonly 50–100 m, and on one occasion 270 m. The internal wave occurred at a number of frequencies. There were a number of spectral peaks at diurnal and semi-diurnal frequencies, as well as intermediate and sub-inertial frequencies, less so at the inertial frequency. At Palau the waves generally did not travel around the island because there was no coherence between internal waves on either side of the island. The internal waves at a site 30 km offshore were out-of-phase with those on the island slopes, suggesting that the waves were generated on the island slope and then radiated away. Palau Island was thus a source of internal wave energy for the surrounding ocean. A numerical model suggests that the tidal and low-frequency currents flowing around the island form internal waves with maximum wave amplitude on the island slope and that these waves radiate away from the island. The model also suggests that the headland at the southern tip of Palau prevents the internal waves to rotate around the island. The large temperature fluctuations (commonly daily fluctuations ≈10 °C, peaking at 20 °C) appear responsible for generating a thermal stress responsible for a biologically depauperate biological community on the island slopes at depths between 60 and 120 m depth. 相似文献
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以苯酚和4—溴苯甲酸为原料,合成一种尚未见文献记载的新化合物——4—溴苯甲酸—2,3,4,5,6—五溴苯酯,用无水三氯化铝催化苯酚的全溴化。此产物可望在阻燃剂方面得到应用。 相似文献
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Klaus Kremling 《Marine Chemistry》1983,13(2):87-108
In June 1981, dissolved Zn, Cd, Cu, Ni, Co, Fe, and Mn were determined from two detailed profiles in anoxic Baltic waters (with extra data for Fe and Mn from August 1979). Dramatic changes across the O2H2S interface occur in the abundances of Cu, Co, Fe, and Mn (by factors of ?100). The concentrations of Zn, Cd, and Ni at the redox front decrease by factors between 3 to 5.Equilibrium calculations are presented for varying concentrations of hydrogen sulfide and compared with the field data. The study strongly supports the assumption that the solubility of Zn, Cd, Cu, and Ni is greatly enhanced and controlled by the formation of bisulfide and(or) polysulfide complexes. Differences between predicted and measured concentrations of these elements are mainly evident at lower ΣH2S concentrations.Cobalt proved to be very mobile in anoxic regions, and the results indicate that the concentrations are limited by CoS precipitation. The iron (Fe2+) and manganese (Mn2+) distribution in sulfide-containing waters is controlled by total flux from sediment-water interfaces rather than by equilibrium concentrations of their solid phases (FeS and MnCO3). The concentrations of these metals are therefore expected to increase with prolonged stagnation periods in the basin. 相似文献