数值模式与统计模型相耦合的近岸海浪预报方法

针对数值模式和统计模型预报近岸海浪存在的局限性,构建了数值模式和统计模型相耦合的近岸海浪预报框架,在模式计算格点和近岸预报目标点之间定义一个海浪能量密度谱传递系数,通过经验正交函数分解和卡尔曼滤波方法建立传递系数的统计预报模型并与数值模式进行耦合。经过对近岸波浪观测站1a的预报试验表明:该方法能够提高近岸海浪有效波高预报精度,有效波高的均方根误差降低了约0.16m,平均相对误差降低约9%。进一步试验和分析发现,该方法的预报有效时间小于24h,将海浪能量密度谱经过分解后得到的基本模态反映了近岸波侯的主要特征,海浪能量密度谱传递系数的变化体现了波侯的季节变化特点。     

近岸海域水沙界面通量与水流挟沙力研究

近岸海域的波浪、潮流及海流等动力因素具有周期性和时间、空间尺度差异大的特点,在综合考虑各动力因子的联合作用时具有较大的难度。本文根据平动动能叠加原理给出了一种近岸动力因子的表达形式,并提出了海洋波动有效速度的概念,结合水沙界面处泥沙通量的切应力与挟沙力关系,得到了水流挟沙力的新的计算公式。指出了水流挟沙力与水流临界速度有关,并且该水流临界速度随水深的增大及相对糙率的减小而增大。采用近岸实测数据和模拟结果,对本文的近岸水流挟沙力公式进行了验证,结果表明该公式的计算值与实测值吻合较好,可以适用于近岸海域。     

山东渤海沿岸第四纪地下卤水研究进展

山东渤海沿海岸广泛分布着丰富的第四纪地下卤水资源。近年来,相关部门大力开发地下卤水资源,其勘察研究程度逐渐提高。但是各勘察区域零散,山东省整个渤海沿岸地区第四纪地下卤水资源整体研究程度不够系统全面。该文在前人资料和研究成果的基础上,从3个方面对该区卤水资源的研究进展进行了综述,结合当前的研究工作分析,指出今后该区卤水资源研究的主要工作是卤水资源的可持续性利用及资源环境的可持续发展。     

人工湿地净化高盐度养殖废水的效果

研究了人工湿地循环处理哈氏仿对虾(Parapenaeopsis hardwickii)高盐度(21.1-23.3)养殖废水的净化效果。人工湿地对高盐度养殖废水中各水质指标去除率为:总氨氮66.7%,亚硝酸盐80.0%,化学需氧量12.5%,浊度69.1%,硝酸盐-12.1%,总氮3.5%,总磷0.0%。养殖池水质状况良好。在试验负载范围内,湿地对总氨氮、亚硝酸盐、浊度的去除量随进水污染负载量的增加而增加。研究表明:人工湿地能持续有效降低哈氏仿对虾养殖废水中的主要水质因子浓度。     

山东省沿海岸带矿产资源分布特征

山东省沿海岸带矿产资源分布广泛,资源储量丰富。由于地壳演化历程的差异,决定其岩石建造和含矿建造的差异,从而导致了各大地构造单元内分布着各具特色的矿产;各个地质历史时期中形成的岩系都分布着一定的矿产。山东省沿海岸带属环太平洋Ⅰ级成矿带,分属于济阳(华北)成矿区、胶北(辽宁-胶东半岛)成矿区和胶南-威海成矿区3个Ⅱ级成矿区。由于山东省区域成矿作用的发生、发展和矿床的形成都受区域地质的发展演化控制,矿产在时间上的分布具有不均一性和规律性。     

海岸带、海岛(礁)数字航空摄影方案优化策略

针对数字航空摄影作业技术流程中的作业标准、精度要求以及各关键指标的控制等问题,从数字航空摄影的技术计划制定、航线规划和各项技术指标的确定等方面入手,对基于海岸带、海岛(礁)特征的航摄分区、航线敷设、地面分辨率的确定、航摄季节与时间选择以及POS辅助航空摄影方案选择等内容进行了研究,为获取满足海洋测绘指标要求的航空摄影数据源提供支持。     

Wetland conservation and sustainable coastal governance in Japan and England

Coastal wetlands present particular challenges for coastal governance and for the implementation of the Ramsar Convention, not least because coastal areas are focal points of human activity and of governance ambiguity. Through the evaluation of Ramsar delivery at both national and local levels in Japan and England, the relationship between Ramsar implementation and coastal governance was examined. In England, Ramsar status is primarily treated as a nature conservation designation which limits the wider opportunities inherent in the designation. In contrast, in Japan, the Ramsar Convention is used as a policy driver at the national level and as a leverage to encourage citizen engagement, economic benefit, and wetland conservation at the local level. It was concluded that through the implementation of the Ramsar Convention in important coastal wetland areas, significant steps can be taken towards delivering integrated approaches to coastal governance.     

Distribution and photoreactivity of chromophoric dissolved organic matter in northern Gulf of Mexico shelf waters

The distribution and photoreactivity of chromophoric dissolved organic matter (CDOM) in the northern Gulf of Mexico along the Louisiana coastal shelf were examined during three cruises in summer 2007, fall 2007, and summer 2008. The influence of the Mississippi River plume was clearly evident as CDOM levels (defined as a₃₀₅) and dissolved organic carbon (DOC) concentrations were well-correlated with salinity during all cruises. Elevated CDOM and CDOM:DOC ratios of surface samples collected offshore of Atchafalaya Bay and the Breton-Chandeleur Sound complex indicated emanations of organic-rich waters from coastal wetlands are also an important source to nearshore shelf waters. Generally, CDOM and DOC levels were highest in surface waters and decreased with depth, but during summer 2007 and summer 2008, CDOM levels in near-bottom samples were occasionally higher than at mid-depths without concomitant increases in DOC. CDOM photobleaching was measured during 24 irradiations using a SunTest XLS+ solar simulator with photobleaching rate coefficients (k₃₀₅) ranging from 0.011 to 0.32 h⁻¹. For fall 2007 and summer 2008, higher k₃₀₅ values were generally observed in samples with higher initial CDOM levels. However, samples collected during summer 2007 did not exhibit a similar pattern nor were there differences in photobleaching rates between surface and bottom samples. Spectral slope coefficients (S_275-295 or S_350-400) and DOC levels were largely unchanged after 24 h irradiations. Modeled CDOM photobleaching for northern Gulf of Mexico mid-shelf waters predicts that during the summer when solar irradiance is high and the water column becomes stratified, nearly 90% of the CDOM in the upper 1 m may be lost to photobleaching, with losses up to 20% possible even at 10 m depth.     

Investigation of three‐dimensional wind flow behaviour over coastal dune morphology under offshore winds using computational fluid dynamics (CFD) and ultrasonic anemometry

The behaviour of offshore‐directed winds over coastal dune and beach morphology was examined using a combination of modelling (3‐D computational fluid dynamics (CFD)) and field measurement. Both model simulations and field measurements showed reversal of offshore flows at the back beach and creation of an onshore sediment transport potential. The influence of flow reversals on the beach‐dune transport system and foredune growth patterns has previously received little attention. Detailed wind flow measurements were made using an extensive array of mast‐mounted, 3‐D ultrasonic anemometers (50 Hz), arranged parallel to the dominant incident wind direction. Large eddy simulation (LES) of the offshore wind flow over the dune was conducted using the open‐source CFD tool openFOAM. The computational domain included a terrain model obtained by airborne LiDAR and detailed ground DGPS measurements. The computational grid (~22 million cells) included localized mesh refinement near the complex foredune terrain to capture finer details of the dune morphology that might affect wind flows on the adjacent beach. Measured and simulated wind flow are presented and discussed. The CFD simulations offer new insights into the flow mechanics associated with offshore winds and how the terrain steering of wind flow impacts on the geomorphological behaviour of the dune system. Simulation of 3‐D wind flows over complex terrain such as dune systems, presents a valuable new tool for geomorphological research, as it enables new insights into the relationship between the wind field and the underlying topography. The results show that offshore and obliquely offshore winds result in flow reversal and onshore directed winds at distances of up to 20 m from the embryo dune toe. The potential geomorphological significance of the findings are discussed and simple calculations show that incoming offshore and obliquely offshore winds with mean velocities over 13 m s^?1 and 7 m s^?1, respectively, have the potential to create onshore‐directed winds at the back beach with mean velocities above 3.3 m s^?1. These are above the threshold of movement for dry sand and support previous conclusions about the significance of offshore winds in dune and beach budget calculations. Copyright © 2011 John Wiley & Sons, Ltd.     

Development of an automated method for continuous detection and quantification of cliff erosion events

Three intrusive systems of detection and quantification of coastal erosion events (using thermocouples and thermal pins) were developed and tested from 2005 to 2008 in different regions of the Gulf and maritime estuary of the St Lawrence (Quebec, Canada). The 3‐m‐long thermal pins inserted inside unconsolidated deposits allow the monitoring of erosion for a time period sometimes extending over several seasons. The thermocouple or thermocable method allows not only the instrumentation of unconsolidated deposits but also of rocky and cohesive substrate to a depth of 85 cm. An autonomous microclimatic station located near the experimental sites simultaneously samples temperature parameters, precipitation, snow cover, wind speed and direction as well as global radiation. The differential analysis of cliff thermal regime performed simultaneously with an analysis of air temperature makes it possible to determine the activation periods of coastal erosion processes. The results also make it possible to establish with precision the actual influence of rapid variations of certain climatic and microclimatic parameters (radiation, presence of snow cover, precipitation, etc.) on the physical state of surfaces and also on the activation of certain physical processes connected to coastal erosion events. The automated thermal erosion pin system (ATEPS) allows high temporal resolution (i.e. continuous) monitoring, enabling a real coupling of coastal erosion rates and climatic parameters. Preliminary results with the ATEPS system indicate that mild winter temperature and direct solar radiation are significant factors controlling cliff retreat rates. Moreover, the melting of segregation ice during the spring thaw contributed for more than 70% of cliff retreat against only 30% for frost shattering. Copyright © 2010 John Wiley & Sons, Ltd.