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铁山港海湾是一个遭受风暴潮灾害影响较为严重的半封闭型海湾,基于有限元海洋数学模型ADCIRC (Advanced Circulation Model)研究了1409号"威马逊"台风期间铁山港海湾的风暴潮特征及非线性作用。结果表明:当考虑天文潮与风暴潮之间的相互作用时,风暴潮水位的计算结果更加准确,只考虑纯台风影响时,计算结果会低估风暴潮增水值,高估减水值,对预报结果造成较大的误差。海湾内部的增水要远大于湾外,但是减水值则相差不大。通过对天文潮和风暴潮非线性作用的影响因子进行分析,风应力的浅水效应可以忽略,但底摩擦项和对流项影响较大。在海湾内部对流项占主导地位,与天文潮的耦合作用也较强;而在湾外,底摩擦项占优势,耦合作用在海湾内外都较强。天文潮与风暴潮相互作用产生的非线性水位在湾顶处最大可达0.94 m,出现在风暴潮最大减水时刻,风暴潮增水发生后有所减弱,非线性水位表现出从湾外向湾内递增的规律。 相似文献
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从三维浅海非线性流体动力学模型方程出发，使用进一步发展了的流速分解法，以７１０９号和８００７号台风为例，对北部湾的潮汐与风暴潮的耦合水位及流速进行了数值模拟．计算结果与实测资料基本相符．此外，还对北部湾风暴潮及天文潮的非线性效应进行了数值探讨．提出了有益的结论。 相似文献
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作为半封闭狭长海湾,铁山湾受风暴潮灾害的影响较为严重。根据多年观测资料和数值模型对铁山湾内的风暴潮水位特征进行了研究。观测资料表明海湾内风暴潮峰值水位受天文潮相位影响较为显著,然后基于ADCIRC风暴潮模型和1409号“威马逊”台风参数,定量评估了天文潮对风暴潮水位的影响。模拟结果表明当考虑天文潮作用时,会显著提高模拟结果精度,然后通过数值实验研究了风暴潮与不同相位天文潮相互作用时的水位变化特征。数值实验结果表明天文潮-风暴潮相互作用引起的非线性水位在涨潮阶段不明显,在高潮位时非线性水位达到负值最大;在落潮时达到正值最大。风暴潮增水峰值由于受到这种非线性效应的影响,在高潮位时数值最小。海湾内非线性作用要远大于外部,非线性效应越强,总水位峰值相对于天文潮高潮位的延迟时间也就越长。 相似文献
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上海沿岸天文潮与风暴潮非线性相互作用的数值研究 总被引：10，自引：0，他引：10
运用二维非线性风暴潮，天文潮和联合水位模型８次不同路径的热带气旋引起的上海地区天文潮与风暴潮的非线性相互作用进行了数值研究，讨论了天文潮气与风暴潮非线性相互作用引起的增水特征，分析了控制方程中各非线性项对天文潮与风暴晨线性相互作用引起水位变化的贡献，研究表明，考虑天文潮与风暴的非线性相互作用后，使风暴潮和水位的数值模拟结果得到了改善，非线性底摩擦在控制天文潮和风暴潮非线性相互作用中起重要的作用。而 相似文献
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珠江河口区水网密布,水动力条件复杂,风暴潮增水过程存在明显非线性叠加特征。本文运用ADCIRC(AdvancedCirculationHydrodynamicmodel)与SWAN(SimulatingWavesNearshore)模型,以1713号台风“天鸽”为实例,构建了珠江河口区风暴潮增水数值模拟模型,研究了珠江河口区风暴潮增水非线性叠加特征,得出如下结论:(1)在台风强度不变的情况下,在珠江口西岸登陆台风带来的增水最大,在伶仃洋西岸超过2 m。(2)风暴潮在珠江口西岸、东岸、河口区登陆,在高低潮和低低潮登陆带来的非线性效应水位较高,最高超过1 m。在高高潮和高低潮期登陆带来的非线性效应水位较低,最低非线性水位接近0 m。在珠江口西岸登陆的台风,其风暴潮-天文潮的非线性效应最大。 相似文献
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海浪和潮汐风暴潮耦合过程的数值研究(英文) 总被引：1，自引：0，他引：1
海浪和风暴潮是重要的海洋灾害。对它们的精确预测和预报对沿岸海洋灾害的风险评估及海洋工程的设计具有极其重要的社会和经济价值。过去人们大多对波浪和风暴潮单独进行预报。实际上,风既产生浪又产生风暴潮,因此它们的产生必然存在相互作用。本研究的目的就是要建立一个渤海高分辨率的双向耦合的海浪和潮汐风暴潮数值模式,研究各耦合机制的影响,以期为黄河三角洲沿岸风暴潮海浪漫堤、漫滩风险评估提供更为准确的海浪风暴潮预测预报结果。作者在研究中基于国际上先进的第三代海浪数值模式和潮汐风暴潮模式,建立了渤海2′×2′的海浪和潮汐风暴潮耦合数值模式。耦合模式充分考虑了三个主要耦合物理机制:依赖海浪状态的表面风应力,波-流相互作用底应力和辐射应力。波浪模式主要基于国际上第三代WAM模式,并对其进行了浅水效应的改进,以包括浅水深度破碎引起的能量耗散;潮汐风暴潮模式计算中开边界考虑了10个主要分潮K1,O1,P1,Q1,M2,S2,N2,K2,Sa,Ssa。依赖海浪状态的表面风应力取自Donelan等(1993)的结果,波-流相互作用底应力取自Signell等(1990)对GrantandMadsen(1979)简化的结果,辐射应力以海浪谱表示。耦合计算中,两个模式通过三个耦合机制双向传递所需参量。运用胜利油田中心一号观测的2个同步浪、潮、流资料对所建的耦合模式进行了检验,并通过耦合和非耦合模式结果的对比对各耦合机制的影响效应进行分析研究。研究结果表明,不同物理机制对波高的影响主要由能量方程中以辐射应力表示的波流相互作用所决定;在波-潮耦合作用中,依赖波令的表面风应力和辐射应力对水位是正效应,而波流相互作用底应力对水位是负效应。三个物理机制的综合净效应是正,可增加水位达25cm。比较显示,耦合模式的结果无论对波高还是水位都比非耦合模式的结果好,特别在峰值处。本研究显示耦合模式的结果将改进海浪和风暴潮的模拟精度。所建立的耦合模式将对渤海海浪和风暴潮预报精度的提高,以及为黄河三角洲近岸海浪和风暴潮灾害的风险评估,提供更可靠的参数,具有重要的价值。 相似文献
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Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested. 相似文献
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G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement. 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
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The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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《海洋学报(英文版)》2014,(11):161-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献