Estimation of Water Particle Velocities by Empirical Transfer Function     

Chiu Yung-Fang Kuo Yi-Yu Chief of Coastal Engineering Division 《中国海洋工程》1997,(4)

-In previous and this studies it appears that the linear and nonlinear wave theory can notaccurately and easily predict the water particle velocities.Therefore,different from the theoretical consider-ations,in this study we have attempted to determine the transfer function empirically.Laboratory experi-ments were performed under various wave conditions.The empirical formulas of the transfer function ofthe wave height,angular frequency and water particle velocity were obtained on the basis of these test databy dimensional analysis and regression analysis.In intermediate and deep water depth conditions,thetransfer function was only a function of a nondimensional parameter which is composed of the angular fre-quency,the depth of the velocity gauge under the still water level,water depth and the acceleration of grav-ity.Finally,the empirical formulas were compared with experimental data and observational data formpresent and Cavaleri's(1978)studies.The empirical formulas were found to be in sufficient correl  相似文献   

秦山核电站邻近水域生态特点     

何德华 《海洋学研究》1991,9(2):119-123

本文综述了1989年4月至1990年1月秦山核电站邻近水域生态调查结果,认为,该水域具暖温带强潮河口区生态特征。水体虽含丰富营养盐和充足溶解氧,由于同时存在着各种不利于生物繁殖生长的环境因子,表现为生物资源贫瘠、种类组成简单,测区所代表的强潮河口湾顶区属低生产力水域。  相似文献   

Response of a climate model to tidal mixing parameterization under present day and last glacial maximum conditions     

lvaro Montenegro  Michael Eby  Andrew J. Weaver  Steven R. Jayne 《Ocean Modelling》2007,19(3-4):125-137

Experiments with a climate model were conducted under present day and last glacial maximum conditions in order to examine the model’s response to a vertical mixing scheme based on internal tide energy dissipation. The increase in internal tide energy flux caused by a 120 m reduction in sea level had the expected effect on diffusivity values, which were higher under lower sea level conditions. The impact of this vertical diffusivity change on the Atlantic meridional overturning is not straightforward and no clear relationship between diffusivity and overturning is found. There exists a weak positive correlation between overturning and changes to the power consumed by vertical mixing. Most of the climatic response generated by sea level change was not related to alterations in the internal tide energy flux but rather to the direct change in sea level itself.  相似文献   

An inflection in the rate of early mid-Holocene eustatic sea-level rise: A new sea-level curve from Singapore   总被引：3，自引：0，他引：3  

M.I. Bird  L.K. Fifield  T.S. Teh  C.H. Chang  N. Shirlaw  K. Lambeck 《Estuarine, Coastal and Shelf Science》2007,71(3-4):523-536

This study presents a sea-level curve from 9500 to 6500 cal BP for the farfield location of Singapore, on the Sunda Shelf in southeast Asia. The curve is based on more than 50 radiocarbon dates from elevations of +1.43 m to −15.09 m representing sea-level index points in intertidal mangrove and shallow marine sediments deposited by sea-level rise accompanying deglaciation. The results indicate that mean sea level rose rapidly from around −17 m at 9500 cal BP to around −3 m by 8000 cal BP. After this time, the data suggest (but do not unequivocally prove) that the rate of sea-rise slowed for a period of 300–500 years centred on 7700 cal BP, shortly after the cessation of meltwater input to the oceans from the northern hemisphere. Renewed sea-level rise amounting to 3–5 m began around 7400 cal BP and was complete by 7000 cal BP. The existence of an inflection in the rate of sea-level rise, with a slow-down centred on 7700 cal BP, is broadly consistent with other available sea-level curves over this interval and is supported by evidence of stable shorelines and delta initiation elsewhere at this time, as well as evidence of comparatively rapid retreat of the West Antarctic ice sheet beginning around 7500 cal BP. ‘Stepped’ sea-level rise occurring shortly after 7500 cal BP and also earlier during deglaciation may have served to focus significant post-glacial episodes of human maritime/coastal dispersal, into comparatively narrow time intervals.  相似文献   

粤东后江湾涨落潮下的碎波带波能与滩面地形时空变化分析   总被引：5，自引：1，他引：5  

冯砚青  陈子燊  李志龙  李志强 《热带海洋学报》2005,24(5):11-18

利用涌浪和处于陡滩面、滩面下陡坎和深槽海滩地形条件下的海滩碎波带压力波和滩面地形资料，对碎波带中的入射总波能、长重力波能及两者比值随潮位涨落的变化关系，碎波带动力因子与滩面地形之间的作用关系及典型相关和多维偏交叉谱关系等作了初步分析。结果表明，碎波带中的入射总波能与潮位涨落呈现出一致的变化规律；而碎波带中的长重力波能变化与潮位涨落变化趋势相反；碎波带各动力因子、滩面潜水位和碎波带波浪、潮位及滩面地形引起的滩面陡坎处破波点位置变动等因素的耦合作用，对滩面向海发育和滩面地形变化有重要影响。  相似文献   

Effect of Sea Level Variation on Tidal Characteristic Values for the East China Sea     

于宜法  俞聿修  左军成  万振文  陈宗镛 《中国海洋工程》2003,17(3)

1 .IntroductionTheglobalairtemperatureroseabout 0 .5～ 0 .6°Coverthepast 2 0thcentury ,andtheglobalmeansealevelincreasedbyabout2 0cmduringtheperiod .Theregionalmeansealevelriseswiththerisingglobalmeansealevel.Zuoetal.( 1 997)indicatedthatthemeanrisingrateofabsolutemeansealevelalongtheChinacoastontheassumptionofunifiedisostaticdatumis 2mm a .Woodworth( 1 999)analyzedsealevelspanning 1 76 8tothepresentinLiverpool,andobtainedaseculartrendforheperiodupto 1 880of0 .39± 0 .1 7mm a ,andatrendfort…  相似文献   

用模糊集合观点讨论水团的有关概念   总被引：1，自引：0，他引：1  

李凤岐  苏育嵩  王凤钦  喻祖祥 《中国海洋大学学报(自然科学版)》1989,(Z1)

本文将划分水团的基本原则,概括为水团内部特征的相对均一性及其与外部海水的明显差异性。用模糊集合讨论了水型、水团和水系等有关概念。提出了用模糊集合观点定义水团及其核心、本体、边界与混合区的建议,并以1979年8月黄海和东海表层为例,给出了各水团的隶属函数。计算了其核心、本体、边界、混合区及贴近度,按其模糊性排出了顺序。  相似文献   

对虾封闭式工厂化养殖水环境要素的变化特征及其相互关系   总被引：4，自引：0，他引：4  

童万平  韦蔓新  何本茂 《台湾海峡》2004,23(1):19-23

根据2002年8月7～8日对虾工厂化养成中后期A、B代表池的实测数据，分析讨论了该时期养殖水体中环境要素的变化特征及其相互关系．结果表明：研究水体水温、盐度和溶解氧含量适宜．日变化幅度不大．但pH值略为偏低，而COD值明显偏高．与该时期投饵量大，残饵及排泄物明显增加有关．但对A池来说，生物作用的影响占主导地位，而对B池而言．则以化学过程影响为主．  相似文献   

亚热带沿海景观的旅游保护性开发及建设探讨--以福建沿海为例     

翁毅  周永章  张伟强  储德平 《台湾海峡》2006,25(2):285-294

依据地貌学和风景学的角度,福建沿海景观以闽江口和九龙江口为界可分为3个景观亚区,并具有多样性与复杂性、动态性与脆弱性和关联性与分异性等特征.本文运用景观生态的原理研究沿海景观的构成与格局,在沿海景观的分类和特征概括的基础上,探讨福建沿海景观旅游开发与建设的模式.通过维护沿海景观系统的稳定,优化沿海各景观亚区的分布格局,提高沿海景观的整体舒适性和挖掘文化景观的内涵等应对措施以实现福建沿海旅游的科学发展.  相似文献   

栉孔扇贝升温育苗高产技术   总被引：1，自引：0，他引：1  

于瑞海  徐承阳 《海洋湖沼通报》1992,(2):68-71

在栉孔扇贝升温育苗中,主要改进了亲贝升温促熟培育、产卵与孵化、选幼、幼虫培育等主要技术措施,在105m~3水体中,培育出商品苗85,000,000多粒,取得了可喜的经济效益。  相似文献