浙江省海岸侵蚀及防治概述     

谢钦春  李全兴 《海洋学研究》1992,10(3):46-52

浙江海岸侵蚀现象普遍存在。基岩海岸海蚀地貌发育,因其组成物质抗冲蚀能力强,岸线后退不明显;砂砾质海岸普遍发生侵蚀,尤其是无计划的人工挖沙,造成沙滩减小或消失;淤泥质海岸大多处于缓慢的淤涨状态,但由于自然条件的改变和人为作用的影响,某些岸段发生侵蚀,特别是受到台风暴潮的影响,岸线在短时间内出现大规模后退和滩面下蚀。侵蚀岸段主要见于杭州湾北岸澉浦至金丝娘桥岸段,杭州湾南岸临山至西三岸段及瓯江口北岸盘石至黄华岸段。淤泥质海岸后缘为滨海平原,组成物质为粘土质粉砂,抗冲蚀能力弱,为防止和减轻海岸侵蚀,沿岸建造各类海岸工程(海塘、丁坝、导堤等),提高防潮抗浪能力,在朝滩种植大米草,互花米草,消浪促淤明显。另外,在海岸开发活动中,应加强海岸侵蚀监测和综合管理。  相似文献   

The effect of submarine groundwater discharge on nutrient and salinity regimes in a coastal lagoon off Perth, Western Australia     

R. E. Johannes  C. J. Hearn 《Estuarine, Coastal and Shelf Science》1985,21(6):789-800

Submarine groundwater discharge (SGD) into a coastal lagoon off Perth, Western Australia, contains nitrate and silicate in concentrations two orders of magnitude higher than those of the receiving waters. This discharge delivers enough nitrate to replace that dissolved in the lagoon water mass about every eight days and enough silicate to replace the lagoon silicate in about 48 days. The delivery rate of nitrate nitrogen by SGD is equal to about 48% of that required for observed growth rates of lagoon macrophytes. Surface salinity is lower close to the shore as a result of SGD. During calm conditions a salinity front was observed in the lagoon, with a nearshore pool of nutrient-enriched water floating above the more saline ocean water.  相似文献   

Reliability-based comparative study for mooring lines design criteria     

Alberto Omar Vazquez-Hernandez  Gilberto Bruno Ellwanger  Luís Volnei Sudati Sagrilo   《Applied Ocean Research》2006,28(6):398-406

The characteristic environmental load effect for the design of mooring systems of floating units can be defined by means of three procedures: (a) the one associated to an extreme sea state with a given return period, (b) the worst one from a set of sea states on a contour line associated to a return period or (c) the extreme one based on response statistics for a long-term period. This work presents the result of a reliability-based partial safety factor calibration study for a LRFD mooring line design criteria considering the three approaches mentioned above. The calibration exercise is applied to three FPSOs considering North Sea environmental conditions and different water depths: 200, 800 and 3000 m. The mooring systems investigated take into account mooring lines made up of chains and polyester ropes. It is shown that, among all cases investigated, the design procedure based on the long-term response is the one that presents less scattered reliability indices around the target level.  相似文献   

Nutrients and zooplankton composition and dynamics in relation to the hydrological pattern in a confined Mediterranean salt marsh (NE Iberian Peninsula)   总被引：4，自引：1，他引：4  

Anna Badosa  Dani Boix  Sandra Brucet  Rocío Lpez-Flores  Xavier D. Quintana 《Estuarine, Coastal and Shelf Science》2006,66(3-4):513-522

The role of the hydrological regime in the nutrients and zooplankton composition and dynamics has been analysed in five lagoons of La Pletera salt marshes (NE Iberian Peninsula) during a complete hydrological cycle (2002–2003). Two of the lagoons have their origin in the old river mouths while the other three were recently created in the framework of a Life Restoration project. This fact has also allowed us to study the effect of the lagoon age on nutrient and zooplankton composition and dynamics. The salt marsh hydrology is determined by a prolonged period of confinement without water inputs, irregularly interrupted by sudden water inputs due to flooding events (sea storms or intense rainfalls). While the dynamics of oxidized nitrogen compounds in the lagoons depends on the water inputs variability within each hydrological cycle, the internal load of phosphorus, total nitrogen and organic matter is related more to the cumulative mechanisms during the confinement periods. Accumulation processes may be easily related to lagoon age, since old lagoons have higher content of nutrients and organic matter, suggesting that these lagoons progressively accumulate nutrients during the successive confinement events. This is the usual case for most Mediterranean salt marshes without an artificially manipulated water regime. The zooplankton community in La Pletera integrates the effects of both the hydrological regime and the lagoon age since the former determines the temporal pattern of the main zooplankton species and the latter explains differences in composition and structure between old and new lagoons.  相似文献   

Atmospheric Correction of SeaWiFS Data for the Retrieval of Suspended Sediment in East China Coastal Waters     

廖迎娣  张玮P．Y．Deschamps 《中国海洋工程》2005,19(2):225-234

The data of SeaWiFS (Sea-Viewing Wide Field-of-View Sensor), installed on SeaStar, has been used to generate SSC (suspended sediment concentration) of complex and turbid coastal waters in China. In view of the problems of the SeaDAS (SeaWiFS Data Analysis System) algorithm applied to China coastal waters, a new atmospheric correction algorithm is discussed, developed, and used for the SSC of East China coastal waters. The advantages of the new algorithm are described through the comparison of the restdts from different algorithms.  相似文献   

A Note on Tsunami Bore Front     

Shigehisa Nakamura 《Marine Geodesy》2005,28(4):305-312

A note is presented on tsunami bore front. This tsunami bore front is an old dynamical problem but also a new problem to be understood. The tsunami event on 2004 December 26 has raised this is an urgent problem. The author introduces here a model in order to see a hydrodynamical specific property of the tsunami bore front. This modeling gives us a new understanding about what mechanics is for the interested tsunami bore front, especially, around a coastal zone. This work adds a new understanding about mechanics of water motions as the tsunamis generated by the earthquake undersea at a distant area from the coast. The model in this work points out a specific transitional pattern as a function of time and space of tsunami bore front. This modeling gives what is essential at considering tsunami bore front.  相似文献   

Extremely Shallow-water Morphobathymetric Surveys: The Valle Fattibello (Comacchio, Italy) Test Case     

Luca Gasperini 《Marine Geophysical Researches》2005,26(2-4):97-107

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Comparing the Benguela and Humboldt marine upwelling ecosystems with indicators derived from inter-calibrated models   总被引：10，自引：0，他引：10  

Moloney  Coleen L.; Jarre  Astrid; Arancibia  Hugo; Bozec  Yves-Marie; Neira  Sergio; Roux  Jean-Paul; Shannon  Lynne J. 《ICES Journal of Marine Science》2005,62(3):493-502

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A methodology for assessing the reliability of taut and slack mooring systems against instability     

A.A. Shah  A. Umar  N.A. Siddiqui   《Ocean Engineering》2005,32(10):1216-1234

In the present study, a methodology for reliability assessment of slack and taut mooring systems against instability has been presented. For this purpose, first, stability analysis of slack and taut mooring systems has been carried out and instable regions are obtained using procedure available in the literature. Having known the instable region(s), methodology for reliability assessment has been proposed which is based on Monte Carlo Simulation technique. After using the proposed methodology, probabilities of failure and reliability indices has been obtained for the above systems. Some parametric studies, such as, effect of lower and upper limits of instability and effect of frequency range of generations are also included to obtain the results of practical interest.  相似文献   

福建近海主要经济渔业生物营养级和有机碳含量研究   总被引：2，自引：0，他引：2  

卢振彬  黄美珍 《台湾海峡》2004,23(2):153-158

本文研究了福建近海52种鱼类、6种虾类、4种蟹类、1种虾蛄和4种头足类的食性和营养级及其有机碳含量。结果表明：营养级以鱼类最高，为2．1～3．7级，平均2．65级；头足类为2．04～2．88级，平均2．60级；蟹类2．38～2．73级，平均2．58级；虾类最低，为1．64～2．21级，平均1．96级．干样有机碳含量百分率也以鱼类最高，为33．0％～76．2％(m／m)，平均46．25％(m／m)；头足类为27．80％～46．16％(m／m),平均40．24％(m／m)；虾类为30．60％～38．40％(m／m),平均34．90％(m/m)；蟹类最低,为25．00％～30．78％(m/m)，平均28．24％(m／m),鲜样有机碳含量百分率还是以鱼类最高,为4．80％～29．55％(m／m),平均13．75％(m／m)；蟹类为8．90％～12．68％(m／m),平均10．74％(m/m)；虾类为6．97％～11．53％(m/m)，平均9．55％(m/m)；头足类最低仅为7．38％～8．52％(m／m),平均7．95％(m/m),干样有机碳含量百分率和鲜样有机碳含量百分率与营养级均成正相关，但前者的相关性高于后者。  相似文献