海洋灾害应急管理体系研究——以连江海洋减灾综合示范区为例

应急管理是海洋灾害风险管理和防灾减灾工作的重要内容。应急管理是一个综合复杂的系统,需要各组成部门的协调一致。文章以连江海洋减灾综合示范区为例,详细分析了海洋灾害应急管理体系的总体构成以及完善海洋综合防灾减灾应急预案体系的重要作用。通过连江海域海洋减灾综合示范区建设,进一步规范风暴潮和海浪灾害以及赤潮灾害应急处置流程,提升各级海洋综合减灾能力,为其他沿海地区开展海洋灾害综合示范区建设和海洋综合灾害应急管理体系的构建提供经验和参考。     

The physics of gas chimney and pockmark formation,with implications for assessment of seafloor hazards and gas sequestration

Pockmarks form where fluids discharge through seafloor sediments rapidly enough to make them quick, and are common where gas is present in near-seafloor sediments. This paper investigates how gas might lead to pockmark formation. The process is envisioned as follows: a capillary seal traps gas beneath a fine-grained sediment layer or layers, perhaps layers whose pores have been reduced in size by hydrate crystallization. Gas accumulates until its pressure is sufficient for gas to invade the seal. The seal then fails completely (a unique aspect of capillary seals), releasing a large fraction of the accumulated gas into an upward-propagating gas chimney, which displaces water like a piston as it rises. Near the seafloor the water flow causes the sediments to become “quick” (i.e., liquefied) in the sense that grain-to-grain contact is lost and the grains are suspended dynamically by the upward flow. The quickened sediment is removed by ocean-bottom currents, and a pockmark is formed. Equations that approximately describe this gas–piston–water-drive show that deformation of the sediments above the chimney and water flow fast enough to quicken the sediments begins when the gas chimney reaches half way from the base of its source gas pocket to the seafloor. For uniform near-surface sediment permeability, this is a buoyancy control, not a permeability control. The rate the gas chimney grows depends on sediment permeability and the ratio of the depth below seafloor of the top of the gas pocket to the thickness of the gas pocket at the time of seal failure. Plausible estimates of these parameters suggest gas chimneys at Blake Ridge could reach the seafloor in less than a decade or more than a century, depending mainly on the permeability of the deforming near-surface sediments. Since these become quick before gas is expelled, gas venting will not provide a useful warning of the seafloor instabilities that are related to pockmark formation. However, detecting gas chimney growth might be a useful risk predictor. Any area underlain by a gas chimney that extends half way or more to the surface should be avoided.     

Estimation of survival probability for a ship in beam seas using the safe basin

The purpose of this paper is to analyze the nonlinear ship roll motion equation and the main parameters that induce ship capsizing in beam seas, estimate the survival probability of a ferry in random seas and to find out a risk assessment method for the ship’s intact stability. A single degree of freedom (1-DOF) dynamic system of ship rolling in beam seas is investigated and the nonlinear differential equation is solved in the time domain by the fourth order Runge-Kutta algorithm. The survival probability of a ferry in beam seas is investigated using the theory of “safe basin”. The survival probability is calculated by estimating erosion of “safe basin” during ship rolling motion by Monte Carlo simulations. From the results it can be concluded that the survival probability of a ship in beam sea condition can be predicted by combining Monte Carlo simulations and the theory of “safe basin”.     

An Ecosystem Based Fisheries Management framework: the efficient,regional-level planning tool for management agencies

The value of applying a regional level, Ecosystem Based Fisheries Management (EBFM) framework, which is a step-wise, hierarchical, risk-based approach, was tested on the West Coast Bioregion of Western Australia. With structured stakeholder input, over 600 ecological, social, economic and governance issues were initially identified for the region. This complexity was reduced to a level useful for management by consolidating the individual risks into 60 regional-level risks, with a multi-criteria analysis used to integrate the ecological, social and economic risks into just 24 Departmental-level priorities, which ranged from very low to urgent. Given this success, EBFM-based priorities now form the basis for the Department’s budget planning process, plus the framework is providing a critical link between fishery level issues and the broader processes undertaken by other marine based agencies. The EBFM framework is a significant step forward for the integrated management of natural resources by enabling all assets and issues relevant to stakeholders and government to be holistically considered at a regional level.     

基于协同区位商的北京城市职住要素空间关联

就业地和居住地是城市居民工作以及生活的主要场所,同样也是城市空间结构最重要的组成要素,写字楼与居民楼空间关联性研究对深刻理解职住关系有着至关重要的作用.利用协同区位商方法,对北京市写字楼与居民楼空间关联总体特征和局域空间关联格局进行分析.研究表明:①协同区位商作为一种测量点要素之间联系的方法,能够很好的应用到职住关系的...     

长白山天池火山的危险性和火山碎屑流灾害评估

本文以长白山天池火山１２１５ＡＤ大喷发为参照系,采用了“以古论今”的历史分析方法,对天池火山的危险性和火山碎屑流灾害进行了评估。认为长白山天池火山是具有潜在喷发能力的高危险火山,给出了长白山天池火山的火山碎屑流灾害预测分区图,为各级政府部门合理制定土地使用规划和防灾活动提供了理论依据。     

20 世纪90 年代广州市从业人员的社会空间分异

1990 年以来中国城市的内城区传统工业向郊区外溢,郊区大量劳动密集型国际资本进驻等因素带来城市不同职业从业者的居住空间格局的重构。以1990 年、2000 年广州市“街道层面”的两次人口普查数据为主要数据源,借用经济学中的区位商指标,分析1990~2000 年广州市不同职业从业者的居住空间分异特征,发现工业、低端服务业、高端服务业及政府 机关职员等从业者呈现出差异化的空间分异特征。工业从业者的居住空间从内城区向近郊区、远郊区等转移,低端服务业从业者的居住地一直高度集中于内城区,高端服务业从业者聚居于政府机关附近和高校、科研机构密集区,政府机关职员居住区完全与政府机关相重合。就业地与居住地的临近性是20 世纪90 年代广州城市从业者居住空间最为显著的特征。旧城区产业结构调整、城市空间扩展、郊区国际生产资本进驻、政府为迎合全球化而进行的政策及空间的调整、土地开发与住房商品化以及原有国家事业机关“单位制”居住模式的惯性等成为1990~2000 年广州市不同职业从业者社会空间分异的主要原因。基于区位商的方法来分析不同职业从业者的居住空间分异,为深入解析城市社会空间分异提供了新的研究思路与方法。     

Controls on As, Pb, and Mn distribution in community soils of an historical mining district, southwestern Colorado

 Rico, Colorado is a small mountain community that was developed before the turn of the century around and near underground lead-zinc-silver mines. Today, US regulatory concerns in such communities focus on the metal content, particularly of lead, in community soils. This study integrates bedrock geology, surficial geology, mineralogy and geochemistry in order to define the controls on metal distribution in Rico community soils. The principal constituents of concern are As, Pb, and Mn. The results show that mining-related sources are discrete and localized whereas natural sources, including bedrock (mean Pb content of 3 500 ppm), colluvium (mean Pb content of 1 410 ppm), and older alluvium (mean Pb content of 744 ppm) are wider spread and are the principal sources of metals in Rico community soils. Historical mining sites like Rico should be expected to have significant surficial expressions of mineralized bedrock. In these communities, it is important to accurately define the role of all metal sources as a foundation for determining environmental liabilities, cleanup guidelines, and health risk assessments. The application of geology and mineralogy in support of geochemical characterization is necessary to accurately define the origin and distribution of both anthropogenic and natural metal sources at such sites. Received: 27 December 1996 · Accepted: 21 February 1997     

Incorporating inflow uncertainty into risk assessment for reservoir operation

An attempt of using stochastic hydrologic technique to assess the intrinsic risk of reservoir operation is made in this study. A stochastic simulation model for reservoir operation is developed. The model consists of three components: synthetic generation model for streamflow and sediment sequences, one-dimensional delta deposit model for sediment transport processes in reservoirs, and simulation model for reservoir operation. This kind of integrated simulation model can be used to simulate not only the inflow uncertainty of streamflow and sedimentation, but also the variation in operation rules of reservoirs. It is herein used for the risk assessment of a reservoir, and the simulation is performed for different operation scenarios. Simulation for the 100-year period of sediment transport and deposition in the river-reservoir system indicates that the navigation risk is much higher than that of hydropower generation or sediment deposition in the reservoir. The risk of sediment deposition at the river-section near the backwater profile is also high thereby the navigation at the river-segment near this profile takes high risk because of inadequate navigation depth.     

主成分分析法在海洋工程系统风险分析中的应用

风险分析作为一门新的应用技术，正在不断地为更多的人们所认识。它不仅在重大项目的投资分析中起着不可缺少的重要作用，并且正在被广泛的应用于军事、环境、科学和工程等领域中。但是，如何在系统风险分析中，特别是在工程系统风险分析中对已识别出的风险事件进行量化分析、找出主要风险事件对系统的影响及对子系统的风险程度进行比较和分析仍是一个重要的课题。这个问题的解决将使风险分析更接近工程实际、更具有实际的指导意义。文章介绍了主成分分析法的原理和实施步骤，并通过实例介绍了主成分分析法在系统风险分析中的应用。在系统风险分析中使用主成分分析法，可以对系统中各子系统的风险程度进行客观的评估，并且可以对风险事件进行聚类分析，使风险控制更容易实施，并且使风险分析更接近工程实际、更具有指导意义。文章中还指出了在使用主成分分析法时应注意的问题。