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我国海砂资源的开发与对策 总被引：6，自引：1，他引：5
对国内外海砂开采现状、需求、环境影响综合分析的基础上,认为今后海砂开发势必由近岸向浅海区发展,通过编制海砂开采规划,加强海砂管理,保护海洋环境,加强海砂勘探、开采、洗砂和环境影响评价等工作,为台湾浅滩海砂开采做好技术储备,以促进台湾浅滩海砂开采产业的发展。 相似文献
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海南岛东北部海域海砂资源特征及成因 总被引：2，自引：0，他引：2
海南岛周边浅海海砂资源丰富,其东北部海域砂、砾质沉积物分布面积可达数百平方千米,平均厚度超过10m,均为全新世海相沉积。通过对海南岛东北部海域的水深、地层、沉积物粒度等方面的调查,研究了该区域海砂资源的分布、范围、规模、厚度及沉积环境,对海砂的质量和开发利用进行了初步分析。其中,位于琼州海峡东口的潮流沙脊区是海砂的主要分布区域,沉积厚度在20m以上,海砂分选好、次圆状,砂含量超过80%,海砂各项指标良好,用途广泛。研究区海砂资源主要受海底地形和潮流的共同作用而形成,属全新世陆架潮流沉积体系,近岸处亦受到陆域物质输入和浅水波浪的影响,沉积物来源主要为琼州海峡内部和粤西,海南岛的物质供给可能相对较少。 相似文献
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烟台市海砂资源开发仍存在着无序状态,干群资源保护意识不强,生态环境进一步恶化,工农业生产和人民生活受到严重影响等问题。加强管理,树立以保护为主的可持续发展的观念;制定并实施海砂开发综合管理的法律制度;建立和完善海砂开发利用监测系统和管理信息系统;加强对海岸带功能区划,充分利用和保护海砂资源;用行政手段,制止乱采乱挖,是利用和保护好烟台市海砂资源的有效途径。 相似文献
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《海洋地质与第四纪地质》2016,(6)
对南海北部陆架沉积区244个表层沉积物样品进行了粒度组分、多元统计及输运趋势分析,结果表明:南海北部陆架区共分布9种沉积物类型,粒度组成以砂和粉砂为主,砂含量占绝对优势,沉积物主要粒级为0~8Φ,优势粒级为0~4Φ。研究区东北部粒径较粗,以中砂为主,分选中等-好,负偏,峰态中等-平坦,西南部粒径较细,以粉砂为主,分选较差,正偏,峰态平坦,中间过渡及陆架外缘粒径中等,以细砂为主,分选中等,正偏,峰态尖锐。基于粒度多元统计及输运趋势分析,南海北部陆架划分为3个沉积区:珠江口及粤东近岸沉积区(I区):主要受控于沿岸流,水动力条件较弱,物质来源以珠江、韩江等河流输运物质及近岸基岩风化、岛屿剥蚀作用产物为主,少量东沙群岛海底冲刷剥蚀产物;混合过渡沉积区(II区):受黑潮南海分支、南海暖流及沿岸流共同作用,水动力条件中等,物源复杂多样,为珠江携带陆源物质、台湾浅滩物质以及东沙群岛附近海底剥蚀产物的混合沉积区域;台湾浅滩及珠江古三角洲残留沉积区(III区):受黑潮南海分支、南海暖流、北部九龙江、沿岸流等影响,海洋水动力条件较强,以晚更新世的残留沉积为主,同时可能接受了少量现代沉积物质。 相似文献
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近年来，临海工程建设成为带动沿海经济发展的一个新的经济增长点。许多电站建设、钢铁厂建设都急需土地资源，沿岸海域的围垦为这些项目建设提供了宝贵的土地资源。福建省目前正在进行的三大围垦工程，如福清东壁岛围垦、莆田澄峰围垦、泉州走马埭围垦等以及许多重点项目，如高速公路、渔港、空港建设都需要海砂作为建设填充材料，海砂需求量日益增加。有了市场的需求，许多企业或个人擅自开采海砂现象则变得十分严重。无度、无序的海砂开采造成了十分严重的海洋环境问题。福建省莆田市许多沙滩下蚀、岸线后退、近岸海域生态环境恶化等均与近岸采沙有关；尤其是岸线后退直接威胁到当地老百姓的生命财产。 相似文献
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闽江口及周边海域沉积物输运及资源效应 总被引：1，自引：0，他引：1
河流入海泥沙的大部分主要分布在河口、三角洲及近岸陆架地区,发育一系列的粗颗粒沉积体系,是海砂资源重要分布区。本文以福建闽江口为研究对象,初步探讨了沉积物输运过程及海砂资源的形成机制。观测结果表明,闽江河口水体盐度由河口内部向口外海域逐渐增大,水体浊度总体减小;闽江河口附近海域近底部(距离海底25cm)流向表现出一定的旋转流特征,潮周期内余流表现为向海输运,而推移质输运主要发生在涨潮期间,并且潮周期内净向陆输运。表层沉积物粒度分析结果表明,闽江河口水下三角洲前缘表层沉积物主要由粗颗粒物质组成,沉积物类型以砂和砂质粉砂为主,中值粒径小于4Φ;前三角洲地区表层沉积物主要由细颗粒物质组成,中值粒径介于4Φ—6Φ之间。沉积物粒径趋势分析结果表明,闽江入海泥沙经梅花水道和长门水道入海后,在盐淡水混合、径流、潮流的作用下,在闽江河口形成了四个粗颗粒沉积物汇聚区,成为闽江口地区海砂资源的重要分布区;而细颗粒物质在河口羽流和潮流的作用下向偏东方向输运,形成了以黏土质粉砂为主的前三角洲。 相似文献
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海南岛东南浅海表层沉积物粒度特征及沉积环境 总被引：1，自引：0，他引：1
对海南岛东南浅海377组表层沉积物样品(平均水深112.3 m)开展粒度测定及沉积物类型划分,并运用统计规律及沉积输运趋势分析,探讨了底质沉积物分布格局与物质来源及沉积动力环境关系。结果表明,海南岛东南浅海沉积物类型复杂,共分布13种沉积物类型,粒度组成以粉砂和砂为主,平均粒径均值为5.73Φ,优势粒级为细粉砂级(6~8Φ),分选差。不同海域沉积物粒径差异明显,北部近岸以含砾沉积为主,中部呈NE-SW向的砂质沉积区(水深80~120 m),西南近岸滨海、北中部海域以及东南部海域多为粉砂、黏土沉积。结合地理位置、沉积物源及水动力条件差异,研究区划分为3个沉积区:I区主要以含砾粗颗粒沉积为主,受控于海南岛上径流及强风浪作用,物质来源以万泉河等河流输运及岸线侵蚀物质为主,强动力(高能)沉积环境;II区以砂沉积为主,受到表层流及风浪等共同影响,可能主要是残留滨海沉积混入了海南岛径流及岸线侵蚀、少量珠江流域及外海复杂来源等现代细粒物质的混合沉积,中等动力沉积环境;III区以细粒沉积为主,主要受华南近岸流、风浪作用及南海暖流影响,推测物质来源主要为海南岛河流输入、岸线侵蚀及复杂外海来源细粒物质的加入,弱动力(低能)沉积环境。 相似文献
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《海洋地质与第四纪地质》2001,21(2)
中国海砂资源研究王圣洁 ,刘锡清 ,戴勤奋著 海洋出版社出版本书是国际合作项目 CCOP- DCGM 数字化编图计划和国土资源部海洋地质工作项目 (中国近海建筑砂砾石矿产资源潜力的可视化评价 )共同资助研究的全面总结。全书首次从建筑集料角度系统地介绍了海砂的类型、实验测试方法和资源评价体系 ,通过对我国陆架调查资料的分析 ,确定了中国海砂资源的潜力和分布规律 ;本书还介绍了海砂开采的技术并结合我国建筑用砂的发展趋势讨论了可能出现的资源、环境和可持续发展问题。本书资料详实、内容丰富 ,特别适合从事海洋地质和资源规划以及… 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