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1.
关于淤泥质海岸与粉沙质海岸界定的探讨   总被引:4,自引:2,他引:2  
对以往淤泥质海岸和粉沙质海岸的界定方法进行了回顾和剖析,指出了其中的不足。并根据前人大量试验结果和现场资料,从泥沙粒径、絮凝因子、起动流速、含泥量等因素,结合欧美国家和我国海洋调查规范对泥沙的分类,将泥沙d50<0.016 mm,含泥量大于25%的海岸视为淤泥质海岸;0.016 mm≤d50≤0.12 mm,含泥量小于或等于25%的海岸视为粉沙质海岸,这种海岸的分类不仅与众多泥沙研究成果总体一致,而且包涵了海岸泥沙运动、港口淤积及清淤等组合因素,更贴近于港口工程实际。  相似文献   

2.
武器装备论证是提升军队战斗力的重要环节。本文分析海警舰艇装备论证的重要性,从海警舰艇执勤海域自然海洋环境和执法任务环境2个方面,阐述海警舰艇遂行维权、执法、服务任务时执法执勤环境分析的内容,研究海警舰艇执勤能力需求和与之对应的舰艇装备需求论证方法。从海警部队中长期建设发展规划的研究出发,讨论海警舰艇装备执法执勤需求论证方法,提出海警舰艇装备论证的主要程序。  相似文献   

3.
位于淤泥质海岸上构筑物的设计技术难点之一就是选择何种结构形式以实现工程建设目标。桶式结构可以回避海上软土地基处理技术难点,是适合于淤泥质海岸的一种新型结构。介绍该新型桶式结构在应用中的结构选型、结构稳定性验算和结构设计方法以及工程应用情况等,可供类似工程应用时参考。  相似文献   

4.
Abstract

Threats to the survival of West Indian manatees (Trichechus manatus) vary throughout their range so that protection of this endangered species requires careful planning on a regional and local basis. The importance and vulnerability of various components of manatee habitats in the Crystal River area of northwestern Florida were assessed, using an ordinal‐combination mapping technique similar to procedures practiced in urban and regional planning. Habitat components were mapped and evaluated in juxtaposition with relevant characteristics of human use of the area, to identify areas of existing and potential manatee/human conflicts in need of reconciliation. Areas evaluated as the most important manatee habitats within this region include Crystal Bay and River, Homosassa River, and the Suwannee River estuary. Existing overlap of human activities with important manatee habitats is most critical near the urban communities of Crystal River and, to a lesser degree, Homosassa Springs. The need for integration of this ecological information into coastal land‐use planning is discussed.  相似文献   

5.
研究波浪和潮流作用下水体含沙量的垂线分布,是解析粉沙质海岸滩面泥沙在波浪和潮流作用下泥沙运移形态的重要基础。通过波浪水槽实验和现场观测资料,揭示粉沙质海岸滩面泥沙在波浪和潮流作用下垂线分布特征,并应用泥沙扩散方程,建立起半理论半经验的含沙量垂线分布公式。  相似文献   

6.
侵蚀岸段通常是海堤破损最为频繁、严重的区段,随着极端气候条件增多及人类活动的影响,海岸侵蚀问题加剧,对海堤及后方陆域安全造成较大威胁,现有修复手段大多无法从根本上解决侵蚀型海堤的破坏问题。结合因岸滩侵蚀引起的滨海县振东闸以北段海堤破坏案例,通过现场调研、波浪物理模型试验、理论计算等手段,分析岸滩侵蚀对海堤安全影响的机理,探讨侵蚀岸段海堤修复措施,提出管桩顺坝透射系数、海堤稳定性计算方法。研究认为侵蚀岸段海堤破坏的主要原因是水深增大引起的波浪动力增强,导致在日常条件下护底、护面侵蚀及极端条件下结构失稳。据此提出保滩、加固相结合的侵蚀型岸段海堤修复方案。经波浪物理试验验证,该方案合理、可行。  相似文献   

7.
Abstract

Notions of private property have both legal and political importance. In California, as elsewhere in the United States, these ideas are changing. The rate and direction of this evolution is not different on the coast. But the intense heat generated by competing coastal interests does tend to illuminate these issues more clearly on the coast. The full range of these issues has been raised in California, where an historic attempt is now being made to plan and manage the use of coastal resources. In January 1976 the California Legislature will be presented with a coastal plan which promises to inflame the passions of traditional property rights advocates and environmental zealots alike. Much of the rhetoric surrounding this political struggle is already being couched in legal terms. In an effort to delineate a few of the genuine legal issues raised in this planning process, this article summarizes the law of California which is relevant in defining the permitted scope of public regulatory power over private land use.  相似文献   

8.
淤泥质海岸航道建设期泥沙回淤特征监测研究   总被引:2,自引:0,他引:2  
总结了淤泥质海岸航道建设期的泥沙回淤监测内容和常用的定性分析、定量计算方法以及成果校核验证方法等.以天津大沽沙5万吨级航道为例,给出了其建设期的泥沙回淤监测分析成果,主要包括泥沙回淤厚度和淤积量的计算及成果校核、回淤时空分布规律、开挖前后回淤泥沙的物质组成变化情况、淤泥层厚度及密度垂向分布状况现场监测等.  相似文献   

9.
中国的北极航线机会和威胁分析   总被引:1,自引:0,他引:1  
北极问题的焦点是北极航线权益的竞争.北极航线问题因为北冰洋的融化预期和随之而来的巨大利益而变得愈来愈重要.在分析北极航线问题的重要性的基础上,分析了中国开辟北极航线的机会和威胁.机会主要表现在北极航线的开辟能够降低我国企业的物流成本、北极航线具有巨大旅游价值、亚洲的高纬度港口将成为新的国际航运中心等方面;威胁主要表现在北极航线的价值属于资源拥有者、我国企业面对的竞争将更加激烈、中国的南北方经济将会受到不同影响等方面.进而提出了中国应采取的国家战略,并从中国航运企业的角度提出应对策略.  相似文献   

10.
天津港座落在典型的淤泥质海岸上,曾经是一个世界闻名的严重淤积港口,泥沙问题一度制约了港口的发展。通过长期的测验研究,掌握了水动力和泥沙的基本运动规律,提出了一系列的治理措施和半经验半理论公式,在工程建设中取得了很好的成效,使天津港逐渐发展成为今天的一个国际化、轻淤积、深水大港。  相似文献   

11.
淤泥质海岸天津港工程泥沙治理与功效   总被引:2,自引:0,他引:2  
天津港座落在典型的淤泥质海岸上,曾经是一个世界闻名的严重淤积港口,泥沙问题一度制约了港口的发展.通过长期的测验研究,掌握了水动力和泥沙的基本运动规律,提出了一系列的治理措施和半经验半理论公式,在工程建设中取得了很好的成效,使天津港逐渐发展成为今天的一个国际化、轻淤积、深水大港.  相似文献   

12.
Abstract

This article outlines the steps that have been taken to conserve the coast of Great Britain. It treats the subject historically and emphasizes the ways in which unofficial and official bodies have interacted. Apart from a few very restricted areas, the shoreline is open to all people. The siting of houses, chalets, and huts is strictly controlled. Problems arise from time to time as to the location of nuclear stations, oil storage areas, and similar installations; these issues are settled in full discussions at official inquiries at which all interests—official, business, and conservation–are represented.  相似文献   

13.
针对遗传算法(Genetic Algorithm,GA)和人工神经网络(Artificial Neural Network,ANN)的缺陷,把二者有机结合起来,提出了基于GA-BP神经网络的沿海港口吞吐量的预测模型,并将预测结果与一般BP神经网络做比较,结果表明该模型比一般BP神经网络预测模型的预测精度要高很多.  相似文献   

14.
利用水流泥沙输移方程和淤积公式建立了淤泥质海岸上外航道淤积计算公式,通过水槽实验和数值模拟对公式中的参数作了修订,公式计算结果与物模、数模、现场的资料及规范推荐的公式结果一致。  相似文献   

15.
针对陡坡海岸栈桥式码头在长周期波和浅水变形工况下的波浪浮托力计算问题,以援萨尔瓦多拉利伯塔德省码头建设项目为例,对于上部结构承受的波浪浮托力采用物理模型试验和国内外相关规范手册的理论计算结果对比分析,结果表明:1)理论公式多适用于行进波,对于长周期的卷破波,很少有适用的理论公式;2)断面物理模型试验考虑了陡坡海岸地形、长周期、波浪浅水变形、波浪破碎等因素,较为贴合实际波况,浮托力试验值相对合理准确;3)波浪浮托力的确定建议综合采用物模试验和理论公式的数值。成果用于水工结构的优化设计,并为以后类似工况的码头设计提供一定的借鉴意义。  相似文献   

16.
针对陡坡海岸栈桥式码头在长周期波和浅水变形工况下的波浪浮托力计算问题,以援萨尔瓦多拉利伯塔德省码头建设项目为例,对于上部结构承受的波浪浮托力采用物理模型试验和国内外相关规范手册的理论计算结果对比分析,结果表明:1)理论公式多适用于行进波,对于长周期的卷破波,很少有适用的理论公式;2)断面物理模型试验考虑了陡坡海岸地形、长周期、波浪浅水变形、波浪破碎等因素,较为贴合实际波况,浮托力试验值相对合理准确;3)波浪浮托力的确定建议综合采用物模试验和理论公式的数值。成果用于水工结构的优化设计,并为以后类似工况的码头设计提供一定的借鉴意义。  相似文献   

17.
一次温带风暴潮对天津沿海的影响及特征分析   总被引:1,自引:0,他引:1  
2009年4月15日,我国渤海、黄海部分岸段经历一次较强的温带风暴潮过程。给天津沿海企业及航行或锚泊的船舶造成一定的经济损失。文章利用天气图及海洋站实测水文气象资料分析此次风暴潮过程。  相似文献   

18.
During the seasonal stratification of 1983 and 1984, intensive sampling of the shelf region of the northeast Spanish coast was carried out. This unique dataset is used to define the most salient features of the shelf water dynamics. We show that region has a strong spatial and temporal variability associated with the southward spreading of continental waters from the Rhone river, in the northern gulf of Lyons. Southward spreading begins in early spring and was particularly obvious during June 1983 when strong horizontal density gradients were observed. Spreading almost completely disappears in August when observed upper layer salinities are uniform. We also show that significant shelf/slope water exchange takes place associated with the abrupt topographic canyons found in the region. In particular we observed in June 1983 a small positive geostrophic vorticity region at the Palamós canyon while a larger anticyclonic eddy was observed over the shelf south of this canyon. The biological implications of these two features have been demonstrated. We conclude indicating that in this region where no dominant winds exist, the shelf water dynamics is dominated by the southward spreading of low salinity continental waters and by the intrusion of high salinity open ocean water through submarine canyons.  相似文献   

19.
Responding to the world’s growing demand for oil and gas, Arctic resources have been given much attention by the energy and shipping industries. In addition, global warming has accelerated oil and gas development in the Arctic, particularly in its western region. Ice-diminishing Arctic has inspired the world’s shipping industry to explore the feasibility of the historical Arctic routes, the Northwest Passage and Northern Sea Route, as seasonal commercial sea lanes. The background aspects of the Passages and the main issues to be solved for their commercial openings are discussed in this paper. Challenges to an internationally agreeable Arctic regime, likely the Antarctic Treaty, are crucial for clean production and safe transport of the Arctic resources and the transit passages across the Arctic Ocean.  相似文献   

20.
谢德华 《世界海运》2010,33(1):22-24
淘汰、拆解老旧船舶是当前面对金融危机和今后一段时间内抑制航运、造船市场继续疲软最直接、最有效的措施之一。2009年,航运企业拆船自救促进了拆船业的发展。  相似文献   

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