滨海沙滩冲淤稳定性的数值模拟研究

近几年海洋风暴活动频繁,伴随着人类不合理的海岸工程造成的影响,部分海岸沙滩侵蚀严重,研究海岸沙滩侵蚀机制成为当前海岸工程科学的前沿性问题。本文以日照万平口沙滩为研究对象,根据实测水深地形数据及相关水文气象资料,搭建研究海域处纯潮流作用、波生流作用、单向波流耦合作用、双向波流耦合作用下的泥沙冲淤数值模型,研究不同水动力环境对近岸沙滩稳定性的影响,得出近岸海域受潮流和波浪的共同作用产生泥沙输移。     

大连市渔港邻近海域环境系统健康评价

本文选用2011年三次对大连近岸渔港邻近海域所做水质、沉积物、生物等的监测数据,采用国家海洋局2005年颁布的《近岸海洋生态健康评价指南》中“河口及海湾生态系统生态环境健康评价方法”,对监测海域的海洋生态环境健康状况加以评价。结果显示,大连市渔港邻近海域总体呈亚健康状态,海洋生态环境较为脆弱。     

辽宁省今年划定海洋生态红线

<正>本刊从辽宁省海洋与渔业厅获悉,目前,渤海近岸海域已有近半海域面积划定生态红线,2015年年底前将完成黄海近岸海域的红线划定工作。据悉,去年辽宁省建立并实施渤海海洋生态红线制度,确立了34个生态红线区,面积占近岸海域面积的45.2%,新建6个海洋特别保护区,近岸海域水质监测站位增加到86个,     

应全面推行“湾长制”

正当前,我国近岸海域生态环保和资源管控问题较突出,海洋部门长期监测结果显示,近岸典型生态系统有3/4处于不健康或亚健康状态。建议从国家层面加大海洋生态环境管控力度,强化陆海统筹。应全面推行"湾长制",与"河长制"衔接,实现流域环境质量和海域环境质量同步改善。目前,国家海洋主管部门在推行‘湾长制’方面已     

丹东海洋红海域水动力泥沙环境分析

基于现场实测水文泥沙资料,对丹东海洋红海域的水文泥沙环境进行了研究。研究结果表明:该海域近岸波浪潮流动力不强,正常天气条件下水体含沙量小、潮流输沙能力不强、泥沙来源少、具备建设大型港口的基本条件。由于该海区属于粉沙质海岸,航道泥沙骤淤将是建港中要考虑的重点问题。     

大连太平湾近岸海域环境承载力综合评价研究

海域水环境质量与承载力是生态环境保护与区域经济发展的重要前提条件。针对大连太平湾近岸海域,文章采用集对分析方法、人工神经网络方法和云理论方法,以研究海域32个站位的COD、无机氮、磷酸盐和石油类4个污染因子为承载力评价指标,重点分析太平湾近岸海域的水环境质量和承载力状况;并以不同时期实测资料,分析了太平湾港区工程建设与环境质量间的相互关系,以期为区域经济社会发展和生态环境保护提供基础支撑。     

南黄海辐射沙脊群海域三维水动力数值模拟

基于无规则网格的有限体积海岸海洋模型(FVCOM),建立适用于辐射沙脊群海域的三维潮流数学模型。为了更好地贴合不规则海岸边界,平面采用三角形网格剖分,垂向采用σ坐标进行模拟。结果表明,模型的计算值与观测值吻合良好,较好地反映了研究海域流场的时空分布特征。整个海域流场由南、北两股潮流向弶港辐聚辐散,各深槽流速较大而集中,流向与深槽走向十分一致;弶港以北,表、底层余流方向都是从南到北的沿岸流,南部海域的近岸余流有逆时针的旋转流,近深槽余流大都指向深槽。     

大型海岸工程对水流和泥沙运动的影响研究

在淤泥质海岸建设大型海岸工程,会对周边海域的水沙环境产生一定影响。文章以连云港为例,应用波浪潮流泥沙数学模型,模拟计算了连云港海域大型海岸工程实施后对于水流泥沙运动的影响。研究结果表明:连云港区、徐圩港区以及灌河口双导堤工程实施后,工程区以外的大范围海域潮流场和含沙量场基本没有改变,变化主要集中在工程区和工程区附近近岸海域,总体呈现出动力减弱、含沙量减少的趋势。     

粤东大亚湾水沙环境及岸滩演变分析

根据现场实测水文泥沙及地形资料,对大亚湾海域的自然条件、水沙环境特征及岸滩演变特征进行分析,研究结果表明：大亚湾潮差较小,波浪和潮流动力弱,水体含沙量较低,泥沙来源有限,主要来自近岸附近滩面就地搬运的少量泥沙。湾内底质多为黏土质粉砂,呈现淤积质海岸的沉积特点。因此大亚湾海域水清沙少,自然状态下海床长期保持稳定。近期受港口航道建设、围填海等人类活动的影响,部分海床地形出现较大幅度的冲淤变化。湾内港池、航道疏浚开挖后航槽稳定,回淤强度较小。正确认识该海域的水动力条件、泥沙运移及海床冲淤变化,不仅是开展海岸工程开发建设的关键技术问题,也有利于近岸海洋环境保护及资源开发利用。     

远海岛礁近岸波浪观测技术比选

概述近岸海域波浪观测有关规定和常用观测技术,阐述远海岛礁近岸海区地形特点和环境条件。在此基础上,对适用于远海岛礁近岸海域的波浪观测技术进行比选,并开展现场观测工作,为岛礁工程建设和生态保护等领域提供可靠基础数据。     

Bayesian statistical data assimilation for ecosystem models using Markov Chain Monte Carlo

This study considers advanced statistical approaches for sequential data assimilation. These are explored in the context of nowcasting and forecasting using nonlinear differential equation based marine ecosystem models assimilating sparse and noisy non-Gaussian multivariate observations. The statistical framework uses a state space model with the goal of estimating the time evolving probability distribution of the ecosystem state. Assimilation of observations relies on stochastic dynamic prediction and Bayesian principles. In this study, a new sequential data assimilation approach is introduced based on Markov Chain Monte Carlo (MCMC). The ecosystem state is represented by an ensemble, or sample, from which distributional properties, or summary statistical measures, can be derived. The Metropolis-Hastings based MCMC approach is compared and contrasted with two other sequential data assimilation approaches: sequential importance resampling, and the (approximate) ensemble Kalman filter (including computational comparisons). A simple illustrative application is provided based on a 0-D nonlinear plankton ecosystem model with multivariate non-Gaussian observations of the ecosystem state from a coastal ocean observatory. The MCMC approach is shown to be straightforward to implement and to effectively characterize the non-Gaussian ecosystem state in both nowcast and forecast experiments. Results are reported which illustrate how non-Gaussian information originates, and how it can be used to characterize ecosystem properties.     

A generalized model of pelagic biogeochemistry for the global ocean ecosystem. Part I: Theory

The set of equations for global ocean biogeochemistry deterministic models have been formulated in a comprehensive and unified form in order to use them in numerical simulations of the marine ecosystem for climate change studies (PELAGOS, PELAgic biogeochemistry for Global Ocean Simulations). The fundamental approach stems from the representation of marine trophic interactions and major biogeochemical cycles introduced in the European Regional Seas Ecosystem Model (ERSEM). Our theoretical formulation revisits and generalizes the stoichiometric approach of ERSEM by defining the state variables as Chemical Functional Families (CFF). CFFs are further subdivided into living, non-living and inorganic components. Living CFFs are the basis for the definition of Living Functional Groups, the biomass-based functional prototype of the real organisms. Both CFFs and LFGs are theoretical constructs which allow us to relate measurable properties of marine biogeochemistry to the state variables used in deterministic models. This approach is sufficiently generic that may be used to describe other existing biomass-based ecosystem model.     

Modelling the spatial and temporal variability of the Cretan Sea ecosystem

The ecosystem function of the oligotrophic Cretan Sea is explored through the development and application of a 3D ecological model. The simulation system comprises of two on-line coupled submodels: the 3D Princeton Ocean Model (POM) and the 1D European Regional Seas Ecosystem Model (ERSEM) adapted to the Cretan Sea. For the tuning and initialisation of the ecosystem parameters, the 1D version of the biogeochemical model is used.After a model spin up period of 10 years to reach a quasi-steady state, the results from an annual simulation are presented. A cost function is used as validation method for the comparison of model results with field data. The estimated annual primary and bacteria production are found to be in the range of the reported values. Simulation results are in good agreement with in situ data illustrating the role of the physical processes in determining the evolution and variability of the ecosystem.     

用生态动力学模型分析海带养殖对浮游生态系统的影响

以我国近海典型海带养殖区桑沟湾为例,建立了"浮游植物-海带-浮游动物-营养盐-有机碎屑"生态动力学模型,较好地模拟了不同养殖密度下浮游生态系统结构的变化,通过灵敏度分析,研究状态变量对模型初值和参数变化的响应,提出了参数优化的思路.     

Issues in Underwater Cultural Heritage Impact Assessments in China

Abstract

During the past decades, the number of coastal and marine construction projects has multiplied in China, posing a serious threat to underwater cultural heritage in its waters. In contrast, there are few rules dealing with underwater cultural heritage impact assessment which has not yet become a mandatory procedure in various coastal and marine construction projects. With China putting forward the Belt and Road Initiative, the conflicts between the protection of underwater cultural heritage and the need of various coastal and marine construction projects might become more frequent. Chinese legislation in this domain, undergoing important revision, intends to establish a mandatory procedure of proactive archeological investigation. This revision could have a great influence on the protection of underwater cultural heritage as well as the coastal and marine construction projects in China but the relevant provisions are still far from satisfactory. The present study will review the current Chinese legislation concerning the impact assessment of marine or coastal construction projects on underwater cultural heritage and explore the possibility for further improvement at the legislative level.     

Modelling Pseudocalanus elongatus stage-structured population dynamics embedded in a water column ecosystem model for the northern North Sea

This paper outlines an approach to couple a structured zooplankton population model with state variables for eggs, nauplii, two copepodites stages and adults adapted to Pseudocalanus elongatus into the complex marine ecosystem model ECOHAM2 with 13 state variables resolving the carbon and nitrogen cycle. Different temperature and food scenarios derived from laboratory culture studies were examined to improve the process parameterisation for copepod stage dependent development processes. To study annual cycles under realistic weather and hydrographic conditions, the coupled ecosystem–zooplankton model is applied to a water column in the northern North Sea. The main ecosystem state variables were validated against observed monthly mean values. Then vertical profiles of selected state variables were compared to the physical forcing to study differences between zooplankton as one biomass state variable or partitioned into five population state variables. Simulated generation times are more affected by temperature than food conditions except during the spring phytoplankton bloom. Up to six generations within the annual cycle can be discerned in the simulation.     

Future aspects in marine ecosystem modelling

Existing ecosystem models are briefly presented and summarised. The problem of coupling physical and biological models as well as aspects of prediction and predictability are discussed. The general perception that marine ecosystems are inherently unpredictable due to non-linearity becomes questionable if the response of climate variability in marine ecosystems is analysed. Many authors have shown correlations between climate variability and the variability of abundance or biomass of marine organisms such as phytoplankton, zooplankton, benthos or fish recruitment in different parts of the world ocean. In the northern hemisphere, certain species show a linear response to climate variability mainly during winter and spring. However, the underlying mechanisms are not well understood. Often, a phase lag can be observed between climate variability and the reaction of organisms. The identification of a plausible mediator between climate and biology is difficult, since all possible physicochemical mechanisms having a direct or indirect influence on the variability of abundance or biomass of marine organisms have to be considered as mediator.The understanding of the reason of the phase lag, which possibly implies a “biological memory”, and the identification of all possible mediators are necessary to predict the response of marine organisms to climate variability. The identification of mediators will result in an improvement of coupled models, a deeper understanding of physical–biological interaction and the improvement of predictive capability of marine ecosystem models.     

Trophic flows,ecosystem structure and fishing impacts in the South Catalan Sea,Northwestern Mediterranean

An exploited ecosystem from the continental shelf and upper slope of the Northwestern Mediterranean Sea was described by means of an Ecopath mass-balance model with the aim of characterising its functioning and structure and describing the ecosystem impacts of fishing. This application included some complexities added to the general modelling methodology due to the high biodiversity of the Mediterranean Sea and the multispecific nature of the fishery, and to the difficulties of working with fishing data which are usually irregularly or imprecisely collected. The model comprised 40 functional groups including primary producers, the main species of benthic, demersal and pelagic invertebrates, fishes and non-fish vertebrates and three detritus groups. In addition, trawling, purse seine, longline and troll bait fishing fleets were included.Results showed that the functional groups were organized into four trophic levels with the highest levels corresponding to anglerfish, dolphins, large pelagic fishes and adult hake. The system was dominated by the pelagic fraction, where sardine and anchovy prevailed in terms of fish biomasses and catches. Detritus and detritivorous groups also played key roles in the ecosystem and important coupled pelagic-demersal interactions were described. Considering Odum's theory of ecosystem development, the ecosystem was placed on an intermediate-low developmental stage due, at least partially, to the impact of fishing activity. This highlighted the high intensity of fishing in the ecosystem, in accordance with the general assessment of western Mediterranean marine resources, and fishing fleets were ranked as top predators of the system. The low trophic level of the catch was in line with the long history of exploitation in the area. However, the steady decline of pelagic landings between 1994 and 2003, coupled with a decrease of the pelagic biomass within the system, underlined the low resistance of the system in front of perturbations. This decline was reproduced under Ecosim dynamic simulations combining different scenarios of moderate increase of fishing effort and an environmental forcing affecting the availability of preys to small and medium-sized pelagic fishes under wasp-waist flow control.     

巴布亚新几内亚科考瑞港集装箱吞吐量预测

为评估新建巴布亚新几内亚科考瑞港的建设规模,构建由回归分析模型、腹地集装箱运输需求重力模型、多目标港口模糊评价模型和基于Logit模型的港口选择模型4部分组成的综合预测方法。对巴布亚新几内亚科考瑞港的腹地集装箱运输需求进行预测;并对腹地省份在不同港口的集装箱运量进行测算,从而科学合理地预测科考瑞港的集装箱吞吐量,为实施项目的必要性提供支持。该预测方法使用较少的基础数据即可比较科学客观地预测新建港口的集装箱吞吐量,能够较好地解决在不发达国家或地区统计资料缺失、安全局势不稳定导致腹地调研困难等情况下的吞吐量预测问题,为海外港口的建设、咨询项目提供帮助。     

A Practice-Based Coupling of the Precautionary Principle to the Large Marine Ecosystem Fisheries Management Concept with a Policy Orientation: The Northeast United States Continental Shelf as a Case Example

This article addresses interdisciplinary sustainable aspects of fisheries as part of ocean management. Human-caused impacts and their role as modifiers of living marine resources is discussed. The research note also theorizes about contemporary global change and its prospective biological consequences, especially when coupled with human-induced factors in coastal marine waters. Also addressed is the management and ecological aspects of fish stock populations as part of a large marine ecosystem (LME) in the Northeast United States continental shelf of the Atlantic Ocean with suggestions for an interdisciplinary policy orientation paradigm to foster the sustainability of marine life in the sea.