Numerical simulation of three-dimensional tidal current in the Bobal Sea     

Den Zhenxing  Yang Lianwu  Jose Ozer 《海洋学报(英文版)》1994,13(2):155-172

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Suspended sediment transport of the Hangzhou Bay and its related hydrodynamic analyses     

Li Bogen  Yang Zhaoqing  Xie Qinchun 《海洋学报(英文版)》1993,12(1):39-50

The 25-h measurements of current speed, flow direction, water depth, suspended sediment concentration and salinity were carried out at six anchored stations in the study area during spring and neap tides in winter of 1987 and summer of 1989. Caculations and analyses of the data obtained show that large amounts of suspended sediments are moved back and forth under the action of tidal current, and the net transport of sediment is small, with its predominance upstream in winter and downstream in summer. These calculations and analyses also suggest that the advective transport of sediment is dominant, while the vertical gravitational circulation of the suspended sediment comes next. Meantime, it is indicated that tidal currents play a major role in the suspended sediment transport, and residual flows have effect on the net transport of the suspended sediment, which is more remarkable during neap tide than during spring tide.  相似文献   

周期浅析     

战淑芸  杨淑瑞 《海洋预报》1992,9(4):47-51

本文分析了滑动平均的数据处理方法对周期分析结果产生的影响。提出了过程变量同号积分的数据处理方法,并对亚洲西风指数序列进行了试验分析。分析结果表明,周期的长短与振幅的大小有密切关系,亚洲逐日西风指数的周期振荡具有明显的季节特征。  相似文献   

Study of zooplankton ecology in Zhejiang coastal upwelling system-Zooplankton biomass and abundance of major groups   总被引：1，自引：0，他引：1  

He Dehu  Yang Guanming  Fang Shaojin  Shen Weilin  Liu Hongbin  Gao Aigen  Huang Shuxin 《海洋学报(英文版)》1988,7(4):607-620

The studied area is a shallow water area that belongs to the East China Sea continent shelf. The distribution of zooplankton biomass is higher inshore than offshore. The maximum abundance is in the inshore edge of the centre of upwelling, which is the superposed area of the salinity front and temperature front, due to the fact that the mixture of three different waters has brought about a concentration of nutrients. The herbivorous Euphausia, Copepoda and Tunicata are the major groups of the abundant area. Tunicata possess the possibility to compete against other kinds of herbivorous zooplankton. This means that there is negative correlation between the distribution of Tunicata and that of Copepoda and Euphausia. The positions of maximum areas of zooplankton biomass, phytoplankton individual and the concentration of phosphates and chlorophyll-a overlap one another. In the centre of upwelling, zooplankton can not adapt itself to the environment of lower temperature and less oxygen even with rich nutrient  相似文献   

Numerical Simulation of Residual Circulation due to Bottom Rouglmess Variability Under Tidal Flows in A Semi-Enclosed Bay     

槐文信  T.  Komatsu  曾小辉 《中国海洋工程》2005,19(4):601-612

Nowadays there are some chronic serious environmental problems, such as eutrophication, blue tide and so on, in a complicated coastal zone or a semi-enclosed bay, because the water exchanges between an inner bay and an outer sea is weak compared with the supply of contaminant. Under this situation, a method to improve the water quality by 3-dimensional small unsymmetrical structures has been proposed by Komatsu et al. In this paper, several numerical simulations of the tidal current and concentration for various arrangements of bottom roughness in a semi-enclosed model bay are carfled out with a depth-averaged 2-D numerical model. The model is solved by the hybrid finite analytic method with nonstaggered grid. And the SIMPLES algorithm with Rhie and Chow＇ s momentum interpolation technique is used for the simulation. The effect of Komatsu＇ s method for water purification is examined by numerical simulation. The result of numerical experiment indicates that it is possible to generate a new tidal residual current and to activate a tidal exchange by bottom roughness arrangement only.  相似文献   

三维斜压模式对冬季南海环流的数值计算   总被引：7，自引：0，他引：7  

游小宝  李荣凤  张铭  曾庆存 《海洋学报》2001,23(6):1-10

用一个三维、自由表面、原始方程模式对南海环流进行了计算.计算结果表明:黑潮在巴士海峡以西呈一反气旋弯曲流动路径,有一相对高温高盐的水舌从巴士海峡伸入南海,表明有部分黑潮水侵入南海.冬季南海的一些观测事实在模式结果里得到了很好的反映,像冬季逆风向东北方向流动的“南海暖流”和一些中尺度涡旋.同时还分析了巴士海峡沿120.75°E断面的流速和盐度的垂直结构,并同观测结果进行了比较.根据模式结果,我们还进一步讨论了“南海暖流”的形成和驱动机制.  相似文献   

Semi-Probabilistic Evaluation of System Redundancy for Existing Offshore Structures     

Zhang Shengkun Chen Kaisheng Mu Yang Professor 《中国海洋工程》1995,(1)

In this paper, a new definition of structure system redundancy is proposed in view of the various measures for structure redundancy. By introducing the terms of structure system failure at the mechanism level and equivalent reliability index, the safety for existing offshore platforms can be evaluated by the semi-probabilistic method presented in this paper. Some numerical examples are given and satisfactory results have been obtained.  相似文献   

Behavior of Pile Groups under Lateral Load   总被引：2，自引：0，他引：2  

Yang Keji  Li Qixin Wang Fuyuan Associate Proferssor  Hehai University  Nanjing Engineer  Hehai University  Nanjing 《中国海洋工程》1991,(2)

Based on investigation and model tests, and in combination with the research work on group effect for pile groups under lateral loads relating to the code of fixed offshore platforms, a series of studies have been performed on the behavior and failure mechanism of laterally loaded pile groups, critical pile spacing inducing group effect, lateral bearing capacity of pile groups and its main influence factors, the stress-strain relationship for single piles and pile groups and so on. Some new laws about non-uniformity of load distribution in the longitudinal direction of pile groups and load-deflection (p - y) curves for pile groups have been discovered, and an empirical formula is presented in order to remedy the defect of current calculating methods at home and abroad. These results can be used for reference in the design of pile foundation under lateral loads.  相似文献   

辽宁菊花岛海域沉积物中某些化学要素分布特征研究     

杨新梅  周义华 《海洋湖沼通报》1991,(1):29-34

菊花岛周围海域38个站表层沉积物的铁、锰、铝、钛、磷、有机质、氮、铜、锌、铅、镉、镍和汞等化学要素含量的Q型因子分析计算表明,本区可划分为三个化学元素沉积区:1.海流悬浮沉积区;2.近岸波浪作用区;3.波浪海流作用区。柱状沉积物中铁等化学元素的迁移、富集受氧化——还原界面的控制。  相似文献   

黄河口及其邻近海域营养盐分布特征     

陈淑珠  顾郁翘  刘敏光  张敏秀  杨淑海  李静 《中国海洋大学学报(自然科学版)》1991,(1)

1985年5、8月中法联合调查黄河口海域的营养盐,其样品采用常规的分光光度法测定。营养盐的分布总趋势是河口附近浓度高,外海浓度低,河口与外海浓度之比达数百倍。在河口及其邻近海域营养盐的分布梯度与盐度的分布一致。在河口控制营养盐含量的主要因素是河水和海水的混合过程。在119°30′～50′E,37°25′～38°5′N,PO_4—P,SiO_3—Si出现低值区。在此范围附近恰恰浮游植物的总量比较高。对8月份的02站进行了25h的连续观测,其结果是底层营养盐与盐度有良好的负相关性,而表层的相关性较差 黄河具有很高的氮磷比值,这很可能是农业上用氮肥量增多引起的。  相似文献