概化弯道段潮汐模型系统设计与制作

根据典型弯曲型河口段的宽浅边界形态、水力条件及潮汐特征,依据相似理论确定模型的基本几何及水力参数.分析了河工模型的最大允许变率,借助重力和紊动阻力相似准则确定模型的各项控制比尺.模型由上游延伸段、河道试验段与下游潮汐池组成.采用w形波纹凹槽方式加糙,使模型糙率达到了试验要求.实测资料验证显示了概化模型的合理性.     

人工干预下河北省淤泥质海岸岸线演变及其环境效应分析

以多期地形图、海图, 多时相航空影像图、卫星遥感数据, 多年实测数据为主要数据源, 综合运用GIS 软件室内判读与野外实地调查相结合的技术方法, 系统分析了人工干预下河北省淤泥质海岸岸线近50 a（1956～2006 年）来演变过程、动因, 深入探讨了海岸岸线演变特征及其对周边岸滩产生的环境效应。结果表明： 河北省淤泥...     

Quantitative estimation of intertidal sediment characteristics using remote sensing and GIS

High spatial resolution satellite data (IKONOS) combined with in situ data was used to quantitatively estimate the spatial distribution of tidal flat characteristics for the Hwangdo tidal flat, Cheonsu Bay, Korea. The classification result was accurate in terms of a comparison with the in situ data, and the overall accuracy was 90.7%, which confirmed the validity of the classification. GIS analysis based on a probabilistic model was applied to a quantitative estimation of the relationship between each surface sediment facies and the spectral reflectance. Mud flat facies showed a high positive correlation (R² = 0.91), and sand flat facies showed a high negative correlation (R² = 1.00), which was a good reflection of the sedimentary characteristics of Hwangdo tidal flat. Relationships between each sediment facies and DEM also showed good agreement with the topographic characteristics in the study area. The study revealed that intertidal surface sediment classification using high resolution remote sensing imagery and in situ data successfully shows spectral and topographic characteristics of the study area. It was noted that spectral reflectance was affected by a combination of environmental factors, including grain size, topography, and remnant surface water. It is possible to determine the type of tidal flat through quantitative estimates of the spatial distribution of surface sediments according to their spectral reflectance.     

Invading cord grass vegetation changes analyzed from Landsat-TM imageries: a case study from the Wanggang area, Jiangsu coast, eastern China

Cord grass colonization on the Jiangsu coast, eastern China, modifies the native salt marshes in terms of ecosystem structure. The Landsat TM images from 1992 to 2003 were analyzed to identify salt-marsh vegetation distribution patterns and their changes over this coastal region, in order to evaluate the effects of the spreading of the artificially introduced halophyte Spartina. Supervised classification was performed using Bands 3, 4 and 5 in conjunction with in situ training samples, to derive the distribution pattern of the vegetation in the study area. Further, in order to identify the intertidal areas with different tidal elevations, a data treatment procedure was designed to combine regional water level data using harmonic analysis with the waterlines on the TM images extracted by density slice. The results show that: (1) the Spartina alterniflora area has been expanding towards the sea rapidly since it was introduced, especially at initial stages; (2) in the upper part of the inter-tidal zone, the local marsh plant Suaeda salsa and the exotic species Spartina anglica were present only near the sea dyke, occupying only a small part of the entire salt marsh, and the area of these two species has been reduced by land reclamation; (3) there has been a trend for Spartina alterniflora to become the dominant species in the salt marshes in the study area; and (4) the elevation of Spartina alterniflora’s seaward fringe was close to mean high water on neaps, and its landward boundary was slightly higher than mean high water. The salt marsh environment of the study area has been modified rapidly by the Spartina vegetation for the last 12 years.     

Molluscan Hard-Substrate Associations in the Northern Red Sea

Abstract. The mollusc associations of 29 hard-substrate localities in the Northern Bay of Safaga Red Sea, Egypt were studied. The hard substrates were classified into 7 types: reef flats, intertidal rock bottom, very shallow subtidal conglomerate, Porites carpet, faviid carpet, platy scleractinian association, Sarcophyton carpet. Based on a cluster analysis the molluscs of these hard substrates can be classified into 5 groups: Group A is dominated by Dendropoma maxima , Chamoidea and Tridacna maxima , group B by Pedum spondyloideum, T. maxima and Coralliophila neritoidea , group C by Chamoidea and Cerithium rüppelli , group D by Modiolus auriculatus , Chamoidea, Morula granulata and Nerita albicilla and group E by Chamoidea and Pitar hebraea . The latter group contains only samples which are generally poor in molluscs. Group A molluscs are diagnostic for reef flats, group B for Porites and faviid carpets, group C for Sarcophyton carpets and group D for tidal/shallow subtidal rock substrates. The different hard substrates are therefore characterized by diagnostic mollusc associations and some of them could also be identified in the fossil record.     

海南岛小海沙坝-泻湖-潮汐通道体系自动调整及恶化

本文运用历史地图对比方法，结合现场考察及水文泥沙测量资料，分析海南岛小海口门近40a来的变化过程，找出小海口门在人为作用下的演变规律．结果表明，小海沙坝—泻湖—潮汐通道体系曾是一个稳定的系统，它通过口门断面、地形调整以适应在人类活动作用下口门动力的变化并保持相对平衡．三大人为活动的综合影响，尤其是盐墩三岛的围垦及冈箱养殖，破坏了口门维持的最后动力(潮汐动力)，使小海沙坝—泻湖—潮汐通道体系失去了调整作用，直接导致了口门的迅速缩小．因此小海综合治理的首要任务是小海口门的治理。     

Hashin Failure Theory Based Damage Assessment Methodology of Composite Tidal Turbine Blades and Implications for the Blade Design

A damage assessment methodology based on the Hashin failure theory for glass fiber reinforced polymer (GFRP) composite blade is proposed. The typical failure mechanisms including the fiber tension/compression and matrix tension/compression are considered to describe the damage behaviors. To give the flapwise and edgewise loading along the blade span, the Blade Element Momentum Theory (BEMT) is adopted. In conjunction with the hydrodynamic analysis, the structural analysis of the composite blade is cooperatively performed with the Hashin damage model. The damage characteristics of the composite blade, under normal and extreme operational conditions, are comparatively analyzed. Numerical results demonstrate that the matrix tension damage is the most significant failure mode which occurs in the mid-span of the blade. The blade internal configurations including the box-beam, I-beam, left-C beam and right-C beam are compared and analyzed. The GFRP and carbon fiber reinforced polymer (CFRP) are considered and combined. Numerical results show that the I-beam is the best structural type. The structural performance of composite tidal turbine blades could be improved by combining the GFRP and CFRP structure considering the damage and cost-effectiveness synthetically.     

青岛海湾大桥对胶州湾潮汐、潮流及余环流的影响预测——Ⅰ.胶州湾及邻近海域的潮流

根据崂山头、朝连岛、灵山岛一个月的潮位资料,采用三角形网格的分步杂交方法,建立了胶州湾及邻近海域的二维变边界潮流数值模型。并模拟了大、中、小潮三种潮汛条件下的潮流场,水位场及余流场。得出了胶州湾高潮水域面积、潮间带面积,湾口累积流通量等有关参数。