Optimization Mathematical Model of Pile Forces for Offshore Piled Breasting Dolphins

An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least number of piles is achieved by the multiplier penalty function method. Several engineering cases have been calculated and compared with the result of the conventional design method. It is shown that the number of piles can be reduced at least by 10%—20% and the piles‘ bearing state is improved greatly.     

近岸溢油漂移扩散预测方法研究——以胶州湾溢油事件为例

近些年,由于中国经济的高速发展,原油需求逐年增长,同时海上溢油事故发生的风险也在加剧。海上溢油会严重破坏海洋环境,危害我国经济发展,加强溢油漂移扩散预报研究能够为海上溢油应急响应提供技术支撑。因此,国家海洋信息中心研发了海上突发事件应急一体化预测预警系统。该系统基于GIS平台研发,能够在二维电子海图基础上叠加相关的海洋环境动力要素信息,模拟溢油扩散和漂移态势,同时计算剩余油量,估算溢油面积以及岸线吸附程度等。2013年11月22日,山东黄岛发生输油管道爆炸事故,造成大量原油溢入胶州湾。本文利用该系统结合高分辨率大气模型WRF的三重嵌套技术和海流模型SELFE的非结构化网格加密技术,对事故溢油漂移扩散开展了预测工作。预测结果显示,油污受胶州湾内往复流的影响极大,72 h后,胶州湾内外大部分海域都将存在油污,主要集中在黄岛沿岸海域、团岛及浮山湾附近,预测扫海面积为70.32 km2。经海事部门高分辨率卫星观测结果印证,系统模拟的溢油分布较为合理。该系统的业务化应用为相关海上溢油污染应急工作提供了一定理论依据和参考。     

Sustainable shellfish aquaculture in Saldanha Bay,South Africa

The carrying capacity for bivalve shellfish culture in Saldanha Bay, South Africa, was analysed through the application of the well-tested EcoWin ecological model, in order to simulate key ecosystem variables. The model was set up using: (i) oceanographic and water-quality data collected from Saldanha Bay, and (ii) culture-practice information provided by local shellfish farmers. EcoWin successfully reproduced key ecological processes, simulating an annual mean phytoplankton biomass of 7.5 µg Chl a l^–1 and an annual harvested shellfish biomass of about 3 000 tonnes (t) y^–1, in good agreement with reported yield. The maximum annual carrying capacity of Small Bay was estimated as 20 000 t live weight (LW) of oysters Crassostrea gigas, or alternatively 5 100 t LW of mussels Mytilus galloprovincialis, and for Big Bay as 100 000 t LW of oysters. Two production scenarios were investigated for Small Bay: a production of 4 000 t LW y^–1 of mussels, and the most profitable scenario for oysters of 19 700 t LW y^–1. The main conclusions of this work are: (i) in 2015–2016, both Small Bay and Big Bay were below their maximum production capacity; (ii) the current production of shellfish potentially removes 85% of the human nitrogen inputs; (iii) a maximum-production scenario in both Big Bay and Small Bay would result in phytoplankton depletion in the farmed area; (iv) increasing the production intensity in Big Bay would probably impact the existing cultures in Small Bay; and (v) the production in Small Bay could be increased, resulting in higher income for farmers.     

黄海、渤海底层温度数值预报方法的研究

根据文献［ｌ］建立的底层温度（ＴＨ）与其水柱垂向平均温度（）的经验关系，结合流体动力学方程和（垂向平均）热传导方程，发展了以水气温差和风速为已知量的底层温度二维数值预报模式。该模式避开了海面热量和动量输入在垂直水柱中分配的复杂物理过程而直接报出底层水温场，具有较好的实用性；此外，从试报结果看，效果令人满意。     

Seasonal variations of water system distribution and flow patterns in the southern sea area of Hokkaido,Japan

Hydrographic data and composite current velocity data (ADCP and GEK) were used to examine the seasonal variations of upper-ocean flow in the southern sea area of Hokkaido, which includes the “off-Doto” and “Hidaka Bay” areas separated by Cape Erimo. During the heating season (April–September), the outflow of the Tsugaru Warm Current (TWC) from the Tsugaru Strait first extends north-eastward, and then one branch of TWC turns to the west along the shelf slope after it approaches the Hidaka Shelf. The main flow of TWC evolves continuously, extending eastward as far as the area off Cape Erimo. In the late cooling season (January–March), part of the Oyashio enters Hidaka Bay along the shallower part of the shelf slope through the area off Cape Erimo, replacing almost all of the TWC water, and hence the TWC devolves. It is suggested that the bottom-controlled barotropic flow of the Oyashio, which may be caused by the small density difference between the Oyashio and the TWC waters and the southward migration of main front of TWC, permits the Oyashio water to intrude along the Hidaka shelf slope.     

Interstitial water chemistry of the inner continental shelf sediments off the gironde estuary

The interstitial water composition ( , alkalinity, Ca²⁺, Mg²⁺, Sr²⁺, Na⁺, K⁺) and the cation exchange capacity (CEC) were determined for the muddy sediments of the continental shelf off the Gironde Estuary (France), in the area where the sediment represents the deposit of the muddy suspension of the river. In comparison with seawater concentrations, the pore waters below 10 cm depth, show depletions of and Ca²⁺ and below a 30 cm depth show depletions of Mg²⁺. Inversely, the upper 10 cm an enrichment of Ca²⁺ concentration, and an increase of K⁺ concentration to a 40 cm depth. High values of are observed at the top 4 cm. Alkalinity enrichment is observed along the length of the core. Applying the alkalinity models for the sediment below a 10 cm depth demonstrates generally that calculated alkalinities are higher than the measured ones. Ca²⁺ dissolution occurs at the first 10 cm and authigenic carbonate precipitation starts beneath that level. Mg²⁺ depletion is accompanied by bicarbonate loss. This proves that Mg²⁺ depletion is due to a Mg-silicate reaction. The result of the CEC does not confirm the Mg²⁺ uptake by clay minerals in exchangeable site, under reducing conditions. Diffusion and bioturbation play an important role in the pore water concentration at the top of the core.     

A Numerical Model of Coastal Processes of Sand Beaches Based on Long-Term Wave Series

A numerical model of shoreline change of sand beaches based on long-term field wave data is proposed, the explicit and implicit finite difference forms of the model are described, and an application of the model is presented. Results of the application indicate that the model is sensitive to the order of the input wave data, and that the effects of long-term wave series and the effects of the mean annual wave conditions on the model are different. Instead of a single wave condition, the wave series will make the calibration and the verification of the model more practical and the results of the model more reasonable.     

呼伦湖的近期扩张及其与全球气候变化的关系

通过近２０多年湖泊水量平衡分析发现，湖泊水位变化主要由湖盆内径流补给量的丰枯决定。进一步分析揭示，呼伦湖地区乃至整个东北地区，本世纪以来随气温升高，随水有增加的趋势。降水增加导致入湖径流量，湖水位上升，呼伦湖本世纪以来的扩张与内蒙古东部地区其他内陆湖泊的变化一致，但这在我国乃至整个亚洲内陆干旱或半干旱区是独一无二的，为此成为这一地区气候变化的指示器。     

应用卫星遥感边缘效应解译冬季黄海的水团配置

作者提出叶绿素是海洋浮游植物生物量的一个重指标,在两水系交汇的锋区,由于浮游植物大量繁殖,叶绿素富集,处于高生产力状态。同步获取黄海叶绿素在富集带及邻近外区的分布,可以确定水团边界。对此,作者根据卫星图象经几何纠正后,通过与黄海叶绿素a的边缘效应信息及区域分布态势比较并解译,将冬季黄海的水团划分为八种。本文还引证了遥感与其它常规资料佐证。     

不规则波折射物理模型试验研究

作者曾发表过“不规则波折射的数学模型〔１〕。为了与数学模型的计算结果相互验证，在大连理工大学海岸及近海工程国家重点实验室进行了不规则波折射物理模型试验。试验研究结果表明：提出的“不规则波折射数学模型”对频谱采用等能量分割、对方向分布采用等间隔（Δθ＝ｃｏｓｎｔ）分割的组成波折射线性叠加法是合理的、可行的，可供港口及海岸工程规划、设计应用