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海洋功能区划是实施海域使用和海洋环境保护管理的重要依据,是实现海域合理开发和可持续利用的重要手段。海岛作为连接陆域和海域的海上基地,其资源丰富,逐渐成为发展海洋经济的第二支点,是海洋功能区划中不可或缺的部分。了解海岛土地利用与覆盖变化是对海岛海洋功能区划执行情况进行评估的基础。遥感具有高分辨率、对同一地区进行快速、重复监测的特点,被广泛用于大范围的土地利用与覆盖变化监测。文章利用国产CBERS-02BCCD遥感影像,对粤西6个主要海岛的功能区划执行情况进行了监测,结果表明：粤西6个主要海岛的实际开发利用类型与区划类型间存在一些不符合区域,这些不符合区域中大部分没有丧失原有属性,即从实际类型可以开发利用为区划类型,但也有部分区域丧失了原有属性,很难再利用为区划类型。 相似文献
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新一轮海洋功能区划修编在即,为平衡海洋资源开发利用和资源环境可持续利用的关系,开展海洋功能区开发潜力研究成为合理确定海域功能的重要依据。本文构建了海洋功能区开发潜力评价模型,从环境生态现状、资源现状、开发现状和社会经济需求四方面选取评价指标,建立海洋功能区开发潜力评价指标体系,并选取具有代表性的江苏滨海县作为研究区,以滨海县各海洋功能区为评价单元开展了实证研究。结果表明:滨海县海洋功能区总体开发潜力较高,环境生态和资源现状等自然条件较好,开发潜力大,但海域开发现状和社会经济需求等社会条件较差,影响了海洋功能区开发的技术支持与需求。 相似文献
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海洋功能区划是海洋环境保护的一项基本制度,海洋功能区划生态环境目标实施效果评价对于总结实施经验、改进区划环境管控目标和完善区划环境保护制度具有重要的意义。文章系统地分析了我国新一轮海洋功能区划生态环境的主要目标、环境保护要求、保障措施等,界定了区划生态环境目标的评估范围。采用基于GIS技术的分析方法,设计了对应关系分析、区划生态环境目标实现程度分析、环境变化趋势分析及影响关系分析等关键环节,探讨了各区划生态环境目标在多个环节、不同情况时的合理性,构建了一套我国新一轮海洋功能区划生态环境目标实施效果评估方法和流程,为开展各级区划生态环境目标实施效果评价提供了技术支撑。 相似文献
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通过海岸自然条件、海洋生态、开发利用现状、社会经济等条件的调查与分析,选取水深、岸线距离、各级居民点距离、沿海支持区域距离、各级道路距离等为主要评价指标,海洋保护区、河口区、天然岸线、重要旅游资源作为限制指标,建立围填海适宜性评价的指标体系。使用基于 GIS 的适宜性评价方法,将辽宁省海洋功能区划范围内海域分为适宜开发区、限制开发区、禁止开发区等5类。其中,围填海适宜开发区面积为701 km2,主要分布于沿岸行政中心和沿海经济带重点支持区域周边;另有部分条件一般的适宜开发区域,总面积3764 km2,大部分分布于沿海水深10 m 以浅海域;其他海域因为各种因素制约,建设开发的条件有限。 相似文献
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通过海岸自然条件、海洋生态、开发利用现状、社会经济等条件的调查与分析,选取水深、岸线距离、各级居民点距离、沿海支持区域距离、各级道路距离等为主要评价指标,海洋保护区、河口区、天然岸线、重要旅游资源作为限制指标,建立围填海适宜性评价的指标体系。使用基于GIS的适宜性评价方法,将辽宁省海洋功能区划范围内海域分为适宜开发区、限制开发区、禁止开发区等5类。其中,围填海适宜开发区面积为701km2,主要分布于沿岸行政中心和沿海经济带重点支持区域周边;另有部分条件一般的适宜开发区域,总面积3 764km2,大部分分布于沿海水深10m以浅海域;其他海域因为各种因素制约,建设开发的条件有限。 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
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Rahul Sharma 《Marine Georesources & Geotechnology》2000,18(3):237-250
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions. 相似文献
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Vance P. Vicente 《Marine Ecology》1989,10(2):179-191
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned. 相似文献
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The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included. 相似文献