The fate of dumped sediments monitored by a high-resolution multibeam echosounder system,Weser Estuary,German Bight

With the development of high-resolution multibeam echosounder systems (MBES) for surveying shallow-water areas a new tool is available to monitor rapid changes in seabed morphology as, e.g., caused by the dumping of dredge spoil in coastal waters. In this study, four data sets of repeated bathymetric surveys with a MBES were processed and analyzed. The data were collected in a 1.94-km² dumping site in the outer Weser Estuary (German Bight). Between June and December 1998, 2.6 million m³ of dredged sediment were deposited there. The bathymetric maps generated in the course of this study reveal features such as subaqueous dunes, scour holes, and mounds of dumped dredge spoil. The mean water depth decreased by about 1 m during the dumping period. Furthermore, difference grids showing changes in sediment volume allowed a calculation of the sediment budget for the monitored area. After a time period of only 5 months, 0.5 million m³ of the originally dumped 2.6 million m³ of dredge spoil had already been removed from the dumping site.     

水动力作用下管道稳定性的试验研究

利用振荡流水槽在以下两种约束条件下，研究波浪作用下直接铺设于砂质海底的管道失稳临界条件：1）管道两端自由；2）管道可水平、垂直自由运动，但流动受到限制。试验结果表明，管重无量纳数G与管道失稳的临界Fr数之间大致呈线性关系，而当G超过一定数值时，管道是侧向稳定的。管道的约束条件、砂床特性和加载速度对管道稳定性均有影响。     

Size-Fractionated Primary Production Estimated by a Two-Phytoplankton Community Model Applicable to Ocean Color Remote Sensing

In order to estimate primary production from ocean color satellite data using the Vertical Generalized Production Model (VGPM; Behrenfeld and Falkowski, 1997), we propose a two-phytoplankton community model. This model is based on the two assumptions that changes in chlorophyll concentration result from changes of large-sized phytoplankton abundance, and chlorophyll specific productivity of phytoplankton tends to be inversely proportional to phytoplankton size. Based on the analysis of primary production data, P _opt ^B , which was one parameter in the VGPM, was modeled as a function of sea surface temperature and sea surface chlorophyll concentration. The two-phytoplankton community model incorporated into the VGPM gave good estimates in a relatively high productive area. Size-fractionated primary production was estimated by the two-phytoplankton community model, and P _opt ^B of small-sized phytoplankton was 4.5 times that of large-sized phytoplankton. This result fell into the ranges observed during field studies.     

经济手段在海岸带环境管理中的应用

简要阐述了环境经济学的基本理论,并以青岛为例,分析了海岸带环境管理现状和现行经济手段存在的问题,提出了运用经济手段加强海岸带环境管理的建议。     

海洋平台结构形状与拓扑优化设计

以实际环境荷载作用下的实际海洋导管架平台结构为对象，研究了海洋平台结构在风，流，海冰等多荷载模式和多荷载工况下的优化设计的理论方法和应用技术，建立了结构尺寸优化，形状优化和拓扑优化问题的统一模型。计算结果反映出形状优化比尺寸优化所得设计更优，而拓扑优化的设计效果最好。不同的荷载工况对应的最优拓扑形式不同，因此在实际设计中应考虑实际的荷载工况，选取不同的拓扑形式。     

桩式离岸堤保滩促淤工程消浪效果试验研究

在上海奉贤南北港保滩促淤工程中，采用了一种新型结构型式－桩式离岸堤，并通过物理模式试验进行了桩式离岸堤消浪效果研究。针对离岸堤通常建于近岸水区破波带的特点，重点研究水深，堤高以及堤身结构对波浪衰减的影响，同时对桩式离岸堤堤后水域的波浪底流速 分析探讨。研究结果表明，桩式离岸堤不仅具有良好的消浪效果。而且可在较大范围内改变波态，即由引起水体剧烈紊动的破波转变为浅水推进波，从而有效地改善海滩上的动力条件，促进海滩免受侵蚀，是一种具有广泛应用前景和新型保滩促淤结构。     

Long-term Sensor Drift Found in Recovered Argo Profiling Floats

We recovered three Argo profiling floats after 2 to 2.5 years of operation, and recalibrated their temperature, conductivity, and pressure sensors. The results demonstrate that these floats exhibited a significant drift in salinity of −0.0074 to −0.0125, primarily due to the conductivity sensor drift. Combined with the recalibration result for another previously recovered float, the indication is that the negative salinity drift increases nearly in proportion to the operating period of floats. The increasing rate is −0.0041 (±0.0015) year⁻¹, which yields a salinity drift of −0.016 (±0.006) for the expected float lifetime of four years. The present result suggests that reducing the float surfacing time would improve the accuracy of the salinity measurements.     

参量阵浅地层剖面技术在海底管道检测中的应用

简要介绍了参量阵浅地层剖面技术——SES 2000型浅剖仪的原理及其在海底管道路由检测中的应用。对掩埋管道赋存的空间状态进行了综合分析研究,并对悬空管道沙包回填后的状态进行了有效辨识,为下一步的管道维护提供了科学依据。     

廉州湾南部海域泥沙来源及运移趋势分析

重矿物组合、含量变化和特征矿物的分布及变化规律是沿海泥沙来源和运移趋势判断的重要手段之一。通过对廉州湾南部海域海底表层沉积物的重矿物分析 ,发现该区重矿物分布以北海地角为界 ,其百分含量和特征矿物南北有别 ,可能分别代表不同的物质来源区。其中廉州湾北部南流江流域来沙是该区主要物源 ,运移趋势为自 NE向 SW;地角西南岸段、岭南侧海岸侵蚀及银滩来沙也为该区提供了部分物源 ,运移趋势为绕过冠头岭沿海岸向 N方向运移。由于缺乏北海陆域陆相地层重矿物含量等相关资料 ,暂未做物质来源区的具体判断     

环境污染物萘、蒽、菲、芘的好氧微生物降解

多环芳烃（PAHs）是环境污染物，具有致癌性和致突变性。选取香港米埔红树林淤泥富集微生物，研究红树林微生物对PAHs的好氧降解。试验观察到，萘、蒽、菲、芘在液体培养条件下均有较强的挥发性。多底物培养液中的菌群浓度明显高于单底物系统。多次连续转接使培养液中的细菌生长能力增强。初始底物浓度可影响细菌生长速率，底物浓度过低或过高均不利于细菌生长。从分离得到的降解菌中选取豚鼠气单胞菌Aeromonascaviae WⅡ和斑点气单胞菌Aeromonas punctata TⅡ进行单菌降解试验，结果表明，豚鼠气单胞菌WⅡ能够高效降解4种底物，而斑点气单胞菌TⅡ能够高效降解萘、蒽和芘3种底物。另外还发现斑点气单胞菌TⅡ能够明显降低水中菲的挥发速度。