Analytical convolution model for shipping water evolution on a fixed structure     

《Applied Ocean Research》2019

The shipping of water is a problem that affects naval and offshore structures. Estimating its propagation on the decks of these structures by using analytical methods has been a main concern of projects. However, classical approaches disregard the decay tendency of water elevation time series and tend to overestimate the resultant water on deck. This paper is concerned with estimating the evolution of water along the deck of a fixed structure due to shipping water events. An analytical convolution model is proposed to estimate water elevations. The model considers the freeboard exceedance time series and the mean shipping flow velocity as inputs and the frictional effects of the bottom by resistance coefficients, which enables an approximated representation of the water elevation time series over the deck. It was validated with experiments of isolated shipping water events that were generated with the wet dam-break approach. The results obtained with the proposed model captured the experimental results, approximating the peak values and the decay trend of time series. Improvement of the proposed approach over classical models to represent shipping water elevations was demonstrated by comparing the results obtained with those of the dam-break model of Stoker.  相似文献   

Greening international shipping through private governance: A case study of the Clean Shipping Project     

Lindsey Wuisan  Judith van Leeuwen C.S.A. van Koppen 《Marine Policy》2012,36(1):165-173

This article aims to generate insights into both private governance and partnerships within the shipping industry, but also tries to improve understanding of the complex process of institutionalisation.This is achieved through a case study of the Clean Shipping Project, a public/private partnership that aims to promote sustainability in the shipping industry. A set of enabling and constraining factors are examined that shape the institutionalisation process and determine to what extent the Clean Shipping Project can establish and expand authority as an industry norm.Overall, the Clean Shipping Project cannot yet be considered a full-fledged private governance institution, because of an insufficient level of collaborative advantage mainly due to weak system robustness and unfavourable market characteristics and conditions. However, institutionalisation is an ongoing process and the future outlook for the Clean Shipping Project remains promising. The Clean Shipping Project is certainly a relevant supplement to existing regulations and there is a basic level of commitment and cohesion within the partnership, so it is not unlikely that in the future this initiative may help to uncouple growth in shipping activities from environmental harm.  相似文献   

Analysis of accidents in Greek shipping during the pre- and post-ISM period     

Ernestos Tzannatos  Dimitris Kokotos 《Marine Policy》2009

In shipping, safety depends on the reliability of the technical and human components of the ship-system, although the marine environment itself may sometimes be so hostile as to give rise to accidents that are beyond technical and human control. The need for a continuous analysis of shipping accidents is dictated by the accumulated evidence for the predominance of the human factor and the ever-increasing pressure for further improvement on the safety record of shipping. In this context, the effectiveness of enforced regulations towards the promotion of safety policy in shipping is assessed and the debate and focus on this issue are maintained.  相似文献   

Implementing the UNCTAD Code of Conduct: The UK Merchant Shipping (Liner Conferences) Act, 1982     

Ademuni Odeke 《Marine Policy》1984,8(1):56-63

This article analyses the UK legislation which will implement the UNCTAD Code of Conduct for Liner Conferences. The historical background to the Merchant Shipping (Liner Conferences) Act, 1982 is outlined and the author points out the relative decline of the UK merchant fleet in the face of competition from developing maritime nations, socialist countries and the USA. Provisions in the UK act curtailing the provisions of the Code are described. UK opposition to the cargo sharing and flag preference provisions of the Code is described and the article concludes by arguing that, although the Code does not satisfy all the UK demands, it remains the best option in a world increasingly dominated by protectionism.  相似文献   

我国航空客流网络发展及其地域系统研究   总被引：69，自引：19，他引：69  

金凤君 《地理研究》2001,20(1):31-39

“极化”效应是高速交通网络引导客货流演进的空间表象,由此导致空间作用关系的变化和空间结构的演化。轴心—附属式的“轴—辐”空间模式已经成为航空客流网络发展的基本模式。本文以航空客流为分析对象,探讨了我国城市间的相互作用特征,以及高速运输网络发展的社会经济意义。结果表明,我国大陆航空客流的网络体系形成了明显的地域分异现象,产生了以三个一级枢纽为核心的“轴—辐”系统,即北京、广州和上海系统,以及两个相对独立的次级系统——乌鲁木齐和昆明系统;航空客流存在显著的距离衰减规律,绝大部分客流发生的距离在2400km之内;超大城市是航空客流的集聚地,以其为枢纽的航空网络的合理组织具有重大的社会经济意义  相似文献   

Sea navigation, challenges and potentials in South East Asia: an assessment of suitable sites for a shipping canal in the South Thai Isthmus     

Rajesh B. Thapa  Michiro Kusanagi  Akira Kitazumi  Yuji Murayama 《GeoJournal》2007,70(2-3):161-172

This paper discusses the situation of sea navigation in south East Asia focusing on the Strait of Malacca. The strait links the Indian and Pacific oceans, which is considered one of the busiest in several narrow channels around the world. The paper highlights the significance of the strait to global maritime trade, volume of traffic, and rising environmental and social consequences in the strait. A feasibility study of constructing a new shipping canal in the South Thai Kra Isthmus as an alternative option of Malacca route had been studied since 19th century. The paper explores suitable sites for a potential shipping canal in the Kra Isthmus using physiographic spatial data i.e., elevation, sea charts, geology, soils and river systems. Each spatial data was considered as a separate decision variable for site evaluation. Separate evaluation criterions were prepared for each variable based on shipping canal requirements. Overlaying the maps in GIS environment, the variables were carefully evaluated, and five geographic sites for the canal were derived. The length of the shipping canal over sea and land was computed for each site. Site B located in south of Ranong and Chumphon provinces, was the shortest one, whereas site C in Surat Thani, Pangnna and Krabi provinces was the longest. However, each site consisted of benefits and constraints.  相似文献   

河流支流入汇口处水利工程防洪设计水位研究:以珠江流域西江桂平航运枢纽为例     

甘富万  黄宇明  张华国  高扬  覃丽娜  肖良 《湖泊科学》2020,32(1):198-206

修建在河流支流入汇口处的水利工程,同时受干、支流洪水共同作用,其防洪水位不但与洪水组合特性有关,还与洪水、水利工程行洪的耦合关系有关.已有采用设计洪水重现期对应的特征洪水组合,或者直接采用经验洪水组合进行调洪计算得到防洪设计水位的方法无法有效反映洪水与水利工程的相互作用.本文结合防洪标准的本质,利用Copula-蒙特卡罗模拟方法对修建在支流入汇口处的水利工程的防洪设计水位进行计算,并以珠江流域西江支流郁江广西桂平航运枢纽水闸为例展开研究.结果表明:Copula-蒙特卡罗模拟方法可以有效考虑干、支流洪水组合特性及其与水利工程行洪的耦合关系,以其计算得到的防洪设计水位唯一且可保证达到防洪标准的要求,可有效克服利用洪水重现期确定防洪设计水位存在的不确定性;在干、支流洪水共同作用下,以设计洪水重现期的不同特征组合计算得到的防洪设计水位相差非常大,且与达到防洪标准要求的防洪设计水位相比完全偏离了合理的误差范围,不宜以设计洪水重现期确定防洪设计水位;利用经验洪水组合计算难以合理反映不同工程的洪水及工程特性.研究成果可为修建在支流入汇口处受干、支流洪水共同影响的水利工程防洪设计提供更合理的理论依据和思路.  相似文献   

集装箱港口体系的演化模式研究--长江下游集装箱港口体系的实证分析   总被引：20，自引：2，他引：18  

曹有挥 《地理科学》1999,19(6):485-490

系统介绍Ｙ．海斯的集装箱港口体系演化模式,对长江下游集装箱港口体系的演化过程进行了科学实证。认为：该集装箱港口体系已经经历了初始,扩散两个阶段,现正处于集中阶段的初期,今后１０年该集装箱港口体系将迅速完成集中化过程,从而进入枢纽中心阶段。  相似文献   

当前我国港口发展条件分析：兼论上海国际航运中心   总被引：27，自引：4，他引：23  

任美锷  杨宝国 《地理学报》1998,53(3):193-201

本文根据我国社会主义市场经济体制及国际上船舶大型化与海洋货运集装箱化趋势,详细讨论了当前和２１世纪初我国港口发展条件。认为社会、经济条件及人为作用对我国港口发展将起来越来越大的作用,传统的“以港兴市”概念已不尽适用。建设上海国际航运中心是国港口建设中的一件大事。上海国际航运中心将以组合港形式组建,包括一个中心港,即上海港,两个次中心港,即北仑港和太仑港,以及若干主要的支线港和喂给港。各港应合理分  相似文献   

Accidental spills at sea - Risk, impact, mitigation and the need for co-ordinated post-incident monitoring     

Mark F. Kirby  Robin J. Law 《Marine pollution bulletin》2010,60(6):797-9297

A fully integrated and effective response to an oil or chemical spill at sea must include a well planned and executed post-incident assessment of environmental contamination and damage. While salvage, rescue and clean-up operations are generally well considered, including reviews and exercises, the expertise, resources, networks and logistical planning required to achieve prompt and effective post-spill impact assessment and monitoring are not generally well established.The arrangement and co-ordination of post-incident monitoring and impact assessment need to consider sampling design, biological effects, chemical analysis and collection/interpretation of expert local knowledge. This paper discusses the risks, impacts and mitigation options associated with accidental spills and considers the importance of pre-considered impact assessment and monitoring programmes in the wider response cycle. The PREMIAM (Pollution Response in Emergencies: Marine Impact Assessment and Monitoring; www.premiam.org) project is considered as an example of an improved approach to the planning, co-ordination and conduct of post-incident monitoring.  相似文献