On the recovery of surface wave by pressure transfer function     

Cheng-Han Tsai  Min-Chih Huang  Fu-Ji Young  Yin-Chern Lin  Hsien-Wen Li 《Ocean Engineering》2005,32(10):4936-1259

Except the commonly selected pressure transfer function derived from the linear wave theory, a previous study on the pressure transfer function for recovering surface wave from underwater pressure transducer suggested that the pressure transfer function is a function of frequency parameter only. With careful analysis, this study showed that the pressure transfer function should include a transducer submergence parameter as that given by the linear theory. It was found that the previously suggested empirical formula should be restricted to measurements with the pressure transducer close to the surface; otherwise overestimation of wave height would result. Field measurements were carried out with an acoustic wave gauge and a synchronized pressure transducer located at various depths with submergence parameter close to 1 (near the sea floor). It was shown that the previous one-parameter empirical formula might overestimate the significant wave height by more than 30%. This study found that with deep-water wave bursts excluded, the transfer function based on the linear wave theory provided a fairly good estimation on the significant wave heights, with an average deviation of 3.6%.  相似文献   

对应分析在法国Douarnenez海湾拟庸鲽食性研究中的应用(Ⅱ)     

林学群  ChristianDENIEL  AlainLAUREC  FranoiseLEMENN 《海洋科学》1994,18(1):29-32

２．４拟庸蝶食性的对应分析２．４．１观察量和变量的分组观察量（捕食鱼类）依不同季节（冬、夏季）、不同性别（雌雄性）和不同性成熟状态（幼鱼和成鱼）来分组，因此得到８（２３）个观察量。对应分析的变量（饵料）首先根据个体生态的不同分为６个类型：游走多毛类，隐居多毛类，双壳类，不大游动的甲壳类（端足目和等足目），爬行甲壳类（十足国短尾部）和棘皮动物。其他６个类型的饵料生物（类、纽虫类、小型游泳甲壳类、腔肠动物、鱼类及苔藓虫类顺在分组时剔除，其原因为它们的出现可能少了些。考虑到捕食鱼类和饵料双壳类贝壳厚度…  相似文献   

Fractal Determination of Coastal Types Based on GIS--A Case Study of China     

Zhu xiaohua  WU Xiuqin  Wang Jian 《海洋通报(英文版)》2002,4(2)

The probability of fractal determination of coastal types based on GIS is preliminarily discussed with China as an example. Finally, some significant conclusions are drawn: (1) The fractal dimension of coastline of the bedrock coast is larger than that of the plain coast on the same scale map; (2) As far as the bedrock coast is concerned, the larger fractal dimension of coastline of the bedrock coast on the same scale map indicates that the bedrock coast is probably not typical; (3) As far as the plain coast is concerned, the smaller fractal dimension of coastline of the plain coast on the same scale map indicates that it is probably the silt plain coast; (4) The different substantial compositions affect the fractal dimensions of coastlines of different coastal types. In general, the coast which lies in the north of the Hangzhou Bay consists of sand mainly, its surface is flat, and it is connected with the coastal plain, its landform is broad shoal, its total change is comparatively homogenous in the tidal dynamic process, and thus, the relatively smaller fractal dimension of coastline results from this. For the bedrock coast, there is more bedrock, the coastline is comparatively smooth and straight, being affected by the faults and ocean dynamic process, which result in the larger fractal dimension.  相似文献   

台湾及其邻海的重力特征与构造、地震的关系   总被引：1，自引：0，他引：1  

张赤军  方剑 《台湾海峡》2001,20(1):101-109

分析认为，在台湾及其邻海的重力场中，具有短波长特征的空间重力异常受地形与海深所制约．玉山的200×10  相似文献   

东海黑潮水与陆架水的季节性输运和交换     

林葵  陈则实  郭炳炎  汤毓祥 《海洋科学进展》1995,(4)

在流星分析和ｔ－Ｓ点聚分析的基础上，在台湾东北部ＩＳ断面和东海中部ＰＮ断面上选取适当的纵剖面作为分界面，将以面分成东、西两侧，计算了界面两侧的海水交换星。结果表明：１．东海陆架区海水交换可归纳为两种类型，即“穿插型”和“进退型”。２．参与分界面处海水交换总量的年平均是夏季最大，春、秋季次之，冬季最小。黑潮水向陆架区输运量为０．５８×１０６ｍ３／ｓ，陆架水向黑潮刚输运量为０．８４×１０６ｍ３／ｓ；参与交换的总量为１．４２×１０６ｍ３／ｓ．３．相对输运量计算结果表明；黑潮水对陆架区水文状况的影响是冬季最强，秋、春季次之，夏季最弱，而陆架水对黑潮区水文状况的影响是夏季最大，秋季次之，春季和冬季最小。  相似文献   

Three-dimensional Layer-integrated Modelling of Estuarine Flows with Flooding and Drying   总被引：1，自引：0，他引：1  

B. Lin  R.A. Falconer 《Estuarine, Coastal and Shelf Science》1997,44(6):737-751

Details are given of the refinement and application of a thee-dimensional (3-D) layer-integrated numerical model of tidal circulation, with the aim of simulating severe tidal conditions for practical engineering applications. The mode splitting strategy has been used in the model. A set of depth-integrated 2-D equations are first solved to give the pressure gradient, and the layer-integrated 3-D equations are then solved to obtain the vertical distributions of the flow velocities. Attention has been given to maintaining consistency of the physical quantities derived from the 2-D and 3-D equations. A TWO=layer mixing length turbulence model for the vertical shear stress distribution has been included in the model. Emphasis has been focused on applying the model to a real estuary, which is geometrically complicated and has large tidal ranges giving rise to extensive flooding and drying. The model has been applied to three examples, including: wind-driven flow in a rectangular lake, tidal circulation in a model rectangular harbour, and tidal circulation in a large estuary. Favourable results have been obtained for both the simple and complex flow beds.  相似文献   

九龙江口红树植物叶片重金属元素含量及动态   总被引：11，自引：0，他引：11  

王文卿  郑文教 《台湾海峡》1997,16(2):233-238

本文探讨了福建九龙江口潮间带秋茄、木榄、红海榄、白骨壤和桐花树等红树植物叶片重金属元素Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ、Ｍｎ的含量及动态。结果表明，该河口红树林区表层土壤沉积物元素含量顺序为Ｍｎ〉Ｚｎ〉Ｐｂ〉Ｃｕ〉Ｃｄ；５种红树植物叶片元素含量顺序为Ｍｎ〉Ｚｎ〉Ｃｕ〉Ｐｂ〉Ｃｄ；不同物种叶片元素含量大都有明显差异；叶片对土壤元素富集系数，以Ｍｎ、Ｃｄ较高，Ｐｂ最低；随叶片从幼叶－成熟叶－黄叶的生长发育，Ｍｎ  相似文献   

东亚和东南亚第四系时间界面的建议     

杨子赓  林和茂 《海洋地质与第四纪地质》1991,11(2):115-128

在东亚和东南亚第四系对比中,有关的几条界限,本文建议如后。采用Globorotalia truncatulinoides的初现位作为本区海相第四系的下界,其位置大致在古地磁Olduvai亚时的下界,时间约为距今1.9Ma。在南中国海、东海及沿岸地区,发现了以G.truncatulinoides的初现位为代表的一系列有意义的生物事件,如Pulleniatina finalis的初现位,Globigerinoides obliquus和Globoquadrina altispira的灭绝位,以及Globorotalia menardii和Pulleniatina obliquloculata壳体旋向的变化。此界限在东亚和东南亚也是相当稳定的。在陆相地层中,以泥河湾组为代表,狭义的泥河湾动物群(相当于晚维拉方动物群)所在地层的底界,其古地磁位置为Olduvai亚时的底界。以此作为陆相第四系的下界,与上述海相第四系底界一致。 以古地磁布容/松山界线作为中更新世和早更新世的界限,其年代为0.73MaB.P.。中国中更新世的标准地层周口店组,其底界恰为布容/松山的转换面,北京猿人的年代为0.60—0.23MaB.P.。在洛川黄土剖面上,布容/松山界线为古土壤S_7的底界。雷琼地区中更新统下部的北海组的底界也是布容/松山界线,所产的玻璃陨石的裂变径迹年龄为0.687—0.733MaB.P.。在黄海,布容/松山界线是第Ⅶ海侵层的顶界。通过岩石地层标志,以及动物群、古人  相似文献   

长江口崇明东滩及相邻区域地形演化与驱动因素分析     

郭兴杰  严学新  王寒梅  沙伟  秦渭华  唐迎洲  徐健 《海洋学报》2020,42(5):95-103

河口大型滩涂演化关系到航运通畅、生态保护以及近岸工程的安全性，是地貌学和工程界关注的热点。利用单波束测深系统对长江口崇明东滩进行高精度监测，并结合近年来周围环境因素分析其冲淤格局。结果表明:(1) 2011?2017年间崇明东滩和北港北沙基本以淤积为主，北港北汊河槽中央局部形成?2 m心滩，?5 m等深线包络面积基本稳定，整体呈“长高不长大”的格局；(2)海洋来沙是其淤积的主要物源，汊道涨落潮时空分异而形成的两大环流是塑造此地形的主要原因；崇明东滩和北港北沙的淤积直接挤压北港北汊的发展，沙体淤积可能会引起未来两大沙体的并靠；(3)崇明东滩、北支南沿的滩涂整治工程是促进北支萎缩和崇明东滩淤积的重要因素，另外横沙通道落潮分流增加,青草沙围水工程改变了北港河槽的曲率，也有利于北港北沙的淤积。  相似文献   

薛家岛湾沉积动力学特征及海港开发研究   总被引：3，自引：0，他引：3  

李凡  林宝荣  吴永成  王从敏 《海洋与湖沼》1994,25(4):452-457

于１９９０年秋对胶州湾内的薛家岛湾进行海洋水动力条件及积动力学特征,泥沙运动规律研究,为开发建设港口提供科学依据。结果表明,湾内深大于１ｍ的海底泥沙发生“全面移动”的时间,一年内仅有１－２ｄ,其余处于稳定状态或“表面移动”状态。湾内泥沙来源很少,预计建港后,港池和航道年平均回淤量分别小于１６ｃｍ,１０ｃｍ对于开发中小型港口十分有利。  相似文献