共查询到20条相似文献,搜索用时 15 毫秒
1.
开展潮流能装置实海况试验、检测与评价方法研究,对海洋高科技成果的转化、海洋可再生能源开发提供了科学、有效的技术保障。文章通过对潮流能装置的功率输出特性、年发电量、能量转换效率三项核心指标进行分析,提出指标的测试内容和评价方法,为实现潮流能海上试验与测试场建设提供技术依据;并根据对海上风电场的研究,提出了海上试验场潮流能装置的电能质量测试与评估方法;给出潮流能装置安全准入的测试内容,全面评估试验场潮流能装置的运行状态。 相似文献
2.
The results obtained with the use of a lowered acoustic Doppler current profiler (LADCP) are presented. The use of the LADCP from a vessel was the first in the history of the study of the Black Sea. The measurements were carried out in the northeastern Black Sea under the auspices of the Black Sea Ecosystem Recovery Program (BSERP) in May 2004. The effect of the computation parameters on the quality and accuracy of the calculations of velocity profiles was studied. It was shown that the use of optimal parameters and reliable navigation data and setting the instrument as close to the bottom as possible could essentially enhance the accuracy of the measurements. The current velocity calculations from the LADCP data were compared with the data on the vessel drift under calm weather. The accuracy of the calculations reached 6–8 cm/s. Recommendations on the choice of the optimal parameters for processing the data on the current velocity are presented. 相似文献
3.
4.
An instrument which measures the velocity and direction of benthic water currents at depths of up to 80 m is described. Characteristics of this meter include: (i) readings are not affected by water flow during sinking or retrieval; (ii) it is portable; (iii) it operates unattended; (iv) it is inexpensive; and (v) it requires only simple maintenance. A timing circuit which operates two time periods in succession is used to activate and de-activate a revolution counter and a fluidfilled compass which are mounted on a special frame and vane system. In the field, the instrument accurately measured average current velocities of up to 6 m s−1. Data are presented which illustrate the usefulness of this instrument in describing the velocity and direction of benthic currents along the east coast of Australia and demonstrate a positive correlation between benthic current velocity and catch rates of the commercially-exploited spanner crab Ranina ranina. 相似文献
5.
Åge Kyllingstad 《Applied Ocean Research》1984,6(3):132-139
This paper concerns mathematical modelling of the hydrodynamic interaction forces between small vertically axisymmetric wave-power devices. The model takes into account small-body approximations for the first order scattered waves but neglects multiple scattering. Further, the local wave fields are neglected, making the model inapplicable for very closely spaced bodies.The model, which is called the low-scattering approximation, comprises analytical formulae for the forces in any of the translation modes surge, sway and heave. It requires, however, that the following isolated-body parameters are known or externally supplied: the added mass and the force coefficients for both heave and surge motion.Comparison with accurate numerical results of a two-buoy system indicates that the present approach is fairly good even when the buoy diameter is as large as 1/6 of the wavelength and the buoy spacing is as small as 5 buoy radii. 相似文献
6.
A 2 1/2-m-high salt-stratified tank has been developed to measure the dynamic response functions of conductivity probes. By using stirring grids to sharpen a two-layer interface, it has been possible to obtain the response functions over the wavenumber range of 0.5 to 300 cycles/m. Test probes, which are mounted on the end of a vertically oriented ram, have been fired through the interface at speeds from 5 mm/s to 3.1 m/s. 相似文献
7.
8.
Celia Ojeda-Martínez Francisca Giménez Casalduero Just T. Bayle-Sempere Carmen Barbera Cebrián Carlos Valle Jose Luis Sanchez-Lizaso Aitor Forcada Pablo Sanchez-Jerez Pablo Martín-Sosa Jesús M. Falcón Fuensanta Salas Mariagrazia Graziano Renato Chemello Ben Stobart Pedro Cartagena Angel Pérez-Ruzafa Fréderic Vandeperre Elisabeth Rochel Serge Planes Alberto Brito 《Ocean & Coastal Management》2009,52(2):89-101
A general conceptual framework for the management of marine protected areas (MPAs) was developed. The driver-pressure-state-impacts-response (DPSIR) framework was used to determine the elements affecting MPAs. The developed evaluation framework helped to select an appropriate suite of indicators to support an ecosystem approach, an assessment of the MPAs functioning and policy decisions. Gaps derived from the management and policy responses in the MPAs were also outlined. It was concluded that the DPSIR framework can help to simplify the complexity of MPA management. This document is a tool for policy makers, scientists and general public on the relevance of indicators to monitor changes and MPAs management. 相似文献
9.
A marine protected area (MPA) potentially generates a wide range of consumptive use, non-consumptive use and non-use values that include: critical habitat protection, conservation of marine biodiversity, recovery of threatened and endangered marine species, increased recreational benefits and increased biomass of harvested marine species. To help assess whether such values exceed the potential costs of MPAs, this paper provides a policy-enabling framework that reviews the existing theoretical and practical instruments and approaches that can be used in the ex-ante evaluation of MPAs. This framework is in three parts. First, a range of alternative monetary and non-monetary techniques to estimate three key economic benefits of MPAs: consumptive, non-consumptive use and non-use values are presented. Second, three decision protocols that can be applied to determine the desirability of establishing MPAs are described. Third, caveats of these approaches and the necessity to accommodate social needs of the communities are provided. The framework shows that biological and ecological considerations together with economic viability and socio-economic factors can and should be taken into account when deciding about when and where to establish MPAs and of what size. 相似文献
10.
《Ocean & Coastal Management》2006,49(5-6):259-280
The development of sustainability indicator systems (SIS) has been a response to practically apply and interpret ecosystem-based and precautionary approaches to fisheries management. Fisheries- based indicator systems have been characterised by recognition of their utility, but hampered by a lack of data, clear roles and responsibilities and an uneven distribution of implementation across governance jurisdictions. This paper explores a policy-based holistic model of an indicator system consisting of inputs, core structures and outputs and uses this as the basis of an assessment framework. The framework is applied to two recent reporting systems: the Australian government's Commonwealth Sustainable Fisheries Assessments and the Marine Stewardship Council initiative. 相似文献
11.
A framework for risk analysis in fisheries decision-making 总被引:4,自引:3,他引:1
12.
We propose a method for the adaptive numerical analysis of current velocities in a basin including a shelf zone and having
a lengthy open boundary with the sea, at which the current velocity is not given. This method is based on a multilayer quasiisopycnic
model. We use an approach according to which one introduces additional terms of the source type into the equations of heat
and salt transfer and the equation of evolution of the thicknesses of layers. We describe the results of calculations of the
current velocities in the northwest part of the Black Sea in June on the basis of climatic data. We also analyse specific
features of thermohaline and dynamic structure of waters.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
13.
Bioavailable contaminant concentrations are an important component in assessing environmental effects as they directly affect ecosystem health. Shellfish contaminant monitoring programmes have traditionally filled this requirement but are being phased out in some jurisdictions. Passive sampling devices (PSDs) have the potential to replace shellfish monitoring; however, there are still knowledge gaps to address before this can occur. This study assessed the suitability of three different PSDs in providing the required information to replace shellfish monitoring. PSDs were deployed at three historic mussel monitoring sites with different levels of urban influence in the Waitemata Harbour, Auckland, New Zealand. Contaminants of interest were urban heavy metals, plus current and emerging organic contaminants. PSDs provided extremely low detection limits and, for some contaminants, very strong correlations to shellfish. PSDs can currently complement shellfish in monitoring, but it is premature to make conclusions as to the suitability of PSDs in replacing shellfish monitoring until more information is available. 相似文献
14.
G. Iglesias J. Rabual M.A. Losada H. Pachn A. Castro R. Carballo 《Ocean Engineering》2008,35(11-12):1113-1120
The prediction of rubble-mound breakwater damage under wave action has usually relied on costly and time-consuming physical model tests. In this work, artificial neural networks (ANNs) are applied to estimate the outcome of a physical model throughout an experimental campaign comprising of 127 stability tests. In order to choose the network best suited to the problem data, five different activation function options and 38 network architectures are compared. The good agreement found between the physical model and the neural network shows that an ANN may well serve as a virtual laboratory, reducing the number of physical model tests necessary for a project. 相似文献
15.
16.
《Marine and Petroleum Geology》2003,20(6-8):883-899
Results from a small set of laboratory experiments are presented here that help further constrain the processes governing the production of turbidity currents from impulsive failures of continental shelf and slope deposits. Three mechanisms by which sediment can be transferred from a parent debris flow to a less-dense turbidity current were observed and quantified. These mechanisms are grain-by-grain erosion of sediment from the leading edge of the parent flow, detachment of thin layers of shearing material from the head of the parent flow, and turbulent mixing at the head of the parent flow. Which transfer process dominates an experimental run depends on whether the large dynamic stresses focused on the head of the debris flow are sufficient to overcome a effective yield strength for the parent sediment+water mixture and on whether the dynamic stresses are sufficient to induce the turbulent flow of the parent mixture. Analysis of data from Marr et al. [Geol. Soc. Am. Bull. 113 (2001) 1377] and Mohrig et al. [Geol. Soc. Am. Bull. 110 (1998) 387] support the use of a shear strength to dynamic stress ratio in constraining necessary critical values for occurrence of the different production mechanisms. Direct sampling of turbidity currents using racks of vertically stacked siphons was used to measure both the quantity of sediment eroded from the heads of non-mixing parent flows and the distribution of particle sizes transported by the developing turbidity currents. Acoustic backscatter imaging was used to better resolve the internal boundary separating any turbulent mixing zone near the front of a flow from unmodified parent material. 相似文献
17.
近岸波生流数值计算的一种新方法 总被引:4,自引:5,他引:4
运用Hardy-Cross法的基本原理建立了一种波生流计算的数值模型.本方法在维持计算稳定性方面表现出色,解决了以往的计算方法所存在的计算不稳定的根本缺陷,但是运用这一方法进行实际问题计算时还明显存在计算收敛缓慢的现象,对此,在探讨计算收敛原因的基础上,提出了同心矩形回路补正、粗网格计算初始值等对策.运用这些对策成功地提高了计算的效率和精度.最后通过计算例验证表明,运用本方法既能有效地维持计算的稳定,又能有效地解决局部缓和法所固有的计算效率低的问题,从而为研究和预测海岸工程对地形及环境变化影响问题提供了合理、实用的方法. 相似文献
18.
This research is an effort to develop a Risk Management-based Decision Analysis (RMDA) framework based on the common fundamental elements that define the nature of resilience in Port Infrastructure Systems (PIS). While developing a systematic process for making strategic and investment decisions, RMDA guides the decision-makers to identify, analyze, and prioritize risks involved in PIS operations; to define ways for risk mitigation, plan for contingencies, and devise mechanisms for continuously monitoring and controlling risk factors and threats to the system; and to value the adopted resilience investment plans and strategies. Our suggested RMDA framework is a policy making tool that utilizes a Decision Tree Analysis (DTA) methodology for assessing the cost-effectiveness of the devised strategies. 相似文献
19.
20.
A process framework is described to address socio-economic issues related to coastal zone management, specifically as it applies to the mitigation of impacts due to the establishment of marine protected areas (MPAs). Analysis of the existing social environment in Tanzania, including social capital, vulnerable groups and livelihood components, was undertaken to allow for the identification of critical issues and challenges. The developed process framework is a guidance document for decision-makers to incorporate the interests and needs of affected stakeholders. This safeguard commits to a consultative process with clear channels of communication, established grievance procedures, and monitoring and evaluation activities for affected communities. 相似文献