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习近平总书记多次就黄河三角洲生态保护和高质量发展作出重要指示批示。长期以来,黄河三角洲的生态保护和高质量发展面临严峻挑战,相应的科技支撑方面也存在一定的问题。本文从黄河三角洲生物多样性保护、生态系统健康和高质量发展两个方面综述了面临的挑战情况,并进一步总结了黄河三角洲生态保护和高质量发展科技支撑存在的问题,概括为“弱”、“散”、“偏”、“缺”四个方面;基于此,提出了黄河三角洲生态保护和高质量发展科技支撑的对策建议,主要是建议成立一个能够提供黄河三角洲生态保护和高质量发展相关问题全套解决方案的研究平台,更有效地为黄河三角洲应用服务单位提供支撑。 相似文献
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科学处理人-地关系、实现海岛保护与发展的平衡是重要的海岛研究课题。《全国海岛保护规划》明确提出在2020年形成以海岛生态旅游等特色产业为主的海岛经济协调发展格局。在生态与产业的融合过程中,出现产业生态化和生态产业化2种需求。对于生态资源优越的海岛而言,生态产业化是未来发展的主要方向,而海岛生态旅游就是海岛地区生态产业化的重要路径。文章考察鸟岛、克里特岛、海龟岛和博基萨岛等海岛生态旅游的国际范本,以我国三大国际旅游岛之一的平潭国际旅游岛为例,说明其生态旅游“工笔画”仍有待临描;以鸟类生态旅游点选划为示例,阐明平潭国际旅游岛观鸟点的选划方案;最后建议推动海岛生态经济示范区建设,并建立国际知名海岛生态旅游合作网络。 相似文献
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为促进浙江舟山群岛新区的高质量发展,文章分析其海岛的开发利用现状和重大战略使命,并提出海岛功能总体布局、功能分类导向和对策建议。研究结果表明:舟山群岛新区的海岛大多数以岛群形式集中分布,目前有居民海岛和部分无居民海岛被不同程度地开发利用,且存在发展差异大、保护力度不够、综合效益较低和战略承载能力不足等问题;基于宁波舟山一体化建设、浙沪自贸区建设、国际油气全产业链建设、海上花园城市建设和海洋生态文明示范窗口建设等重大战略使命,舟山群岛新区的海岛功能总体布局为“一城、两翼,两区”的发展新格局,同时分别建设综合开发利用岛、港口物流服务岛、临港工业制造岛、对外开放合作岛、海洋旅游服务岛、海洋绿色渔业岛和海洋生态保护岛;在主要海岛功能布局的基础上,未来舟山群岛新区应依法管控海岛开发、优化海岛空间规划、完善海岛生态保护、健全岛际交通链接、升级海岛防灾减灾和增强海岛整体智控。 相似文献
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文章结合大连圆岛生态建设实验基地建设工作,对我国小型基岩海岛的特点、功能以及存在的主要生态问题进行系统论述,提出对其适用的生态岛礁建设策略,并在大连圆岛开展实践应用,可为解决我国北方小型基岩海岛长期积累的生态环境问题、提升其对海洋发展的服务功能提供理论和实践指导。研究表明,小型基岩海岛主要存在生态问题突出、自然资源利用不合理等问题,亟须采取明确海岛主体功能、做好生态资源详细调查、保护海岛典型生态资源、加强建设过程监管等策略,强化小型基岩海岛生态保护。 相似文献
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海岛是我国社会经济发展的重要战略空间,也是生态安全的重要屏障,评价海岛的生态状况是海岛合理利用和保护管理的基础。文章选取77个海岛为研究对象,根据海岛生态指数评价方法,对2019年各海岛生态状况进行评价。结果表明:评价海岛以生态状况优良海岛为主,乡镇级有居民海岛和无居民海岛生态状况显著好于村级有居民海岛,渤黄海区和东海区海岛生态指数分布相似,优良海岛比例高于南海区海岛。植被覆盖率、自然岸线保有率和污水处理率是影响海岛2019年生态状况的主要因素。重视和加强村级有居民海岛的生态保护与建设投入力度,合理利用海岛资源,优化保护与开发空间布局,尽可能地保留自然岸线,提高海岛污水处理能力,将有助于改善海岛生态状况,推动实现海岛的可持续发展。 相似文献
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山东省是我国北方海岛最多的省份,海岛作为体现城市海岸带风貌的重要海洋空间资源,是山东省开发海洋的重要基地。随着新时代人民美好生活需求的增长,海岛资源的旅游开发再一次成为政府和学界关注的热点,但与海岛建设日趋活跃相比,相关理论研究仍处于相对滞后的状态。文章从山东省海岛资源的特点认知入手,通过明晰政策目标与开发现状之间的差距,提出“一个调整”“三个整合”和“两个优化”的旅游再开发策略。“一个调整”即海岛旅游开发思路方向调整;“三个整合”即青岛、烟台、威海海岛旅游线路整合,重点海岛群旅游产品整合,海岛与陆域旅游要素整合;“两个优化”为已开发海岛的旅游品质优化,无人海岛的扶持政策优化。通过调整、整合和优化策略,逐步落实相关政策目标,为海岛的可持续、高质量发展提供支撑。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明:土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
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Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
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Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested. 相似文献
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G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement. 相似文献
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Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引:1,自引:0,他引:1
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria ( 〉 99% ), but also between polar marine bacteria and bacteria from other aquatic environments ( ≥ 98.8% ), including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 相似文献
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The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments. 相似文献
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Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献