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91.
本文研究了由2020年12月29日至31日强冷锋引起的影响洋山港海域的温带风暴潮过程。通过气象观测数据分析了其天气过程, 并利用FVCOM-SWAVE波浪-风暴潮耦合模式对该过程进行了高分辨率的数值模拟, 同时结合潮位站及浮标站观测数据对模拟结果进行了验证, 分析模拟了波浪、潮流、风暴增减水特征。结果发现, 该次冷锋型温带风暴潮过程主要表现为先短时风暴增水后出现长时间风暴减水的特征, 最大风暴减水可达65~70cm, 其主要诱因包括研究海域气压的快速升高并维持、长时间持续的偏北大风及波流相互作用。相关敏感试验研究了3种因子对风暴增减水位的贡献大小, 发现风暴增水峰值期间风场贡献占比约为90%, 海平面气压场约为5%; 风暴减水峰值期间, 海平面气压场的贡献度约占55%, 风场约占40%, 而波浪的贡献均不足10%。洋山港航道内风暴期间潮流流速最大可达到2.6~2.8m•s-1, 落潮时为东南向离岸潮流, 涨潮时为西至西北方向的外海潮波传入潮流; 洋山港航道潮流始终是东南或西北向, 此处流速辐合, 是洋山海域流速最高的区域。 相似文献
92.
利用1976—2021年共6期遥感影像获取了海口市东寨港红树林自然保护区范围内不同年代的湿地数据,基于转移矩阵、问卷调查和主成分分析,剖析了45年来保护区红树林的变化及其与周边社区的关系。结果显示:1)保护区内红树林面积由1976年的1 395.84 hm2增至2021年的1 589.28 hm2,期间呈“骤减缓升”之势。除1976—1985年红树林面积有减少外(减少了250 hm2,减少幅度为18%),其余时段红树林面积均为增长态势。2) 1976—2021年保护区红树林转出对象分别是淤泥质海滩(34.32 hm2)、河流(25.81 hm2)、海水养殖场(21.06 hm2)、其他用地(10.58 hm2)和洪泛湿地/内陆滩涂(8.26 hm2);转入为红树林的对象主要是淤泥质海滩(177.41 hm2)、河流(38.18 hm2)、其他用地(28.21 hm 相似文献
93.
提升金融服务实体经济效率是海南自贸港建设亟待研究和突破的“靶点”。论文通过测算2011—2020年海南自贸港18市县金融服务实体经济效率,利用Dagum基尼系数与Kernel密度估计方法刻画效率的时空异质性,并借助随机森林模型揭示其驱动机理,创新性地从时空视角挖掘海南自贸港金融服务实体经济效率分异机制。研究发现:(1)海南自贸港金融服务实体经济效率时空非平衡性明显,时序上阶段性显著,空间上呈西高东低、高值聚集、中部“洼地”的分布特征,西北部市县与中部市县各自逐步形成高值、低值聚集区;(2)总体及沿海市县梯度分化特征逐步加强,而非沿海市县内部差距则逐步缩小,沿海区域金融服务实体经济效率的空间分异是总体分异的主要来源;(3)政府干预是效率分化的主导因素,含金融集聚度在内的影响因素对效率均呈非线性影响且作用趋势与阈值各异,各因素的边际产出能力及各市县对要素的吸收与应用能力的动态差异是时空异质性的主要来源。研究结论可为优化海南自贸港金融资源的空间配置、提升金融服务实体经济效率提供科学依据。 相似文献
94.
This study presents the stratigraphic and floristic interpretations of data collected from a 6.49 m core taken within the Rowley River Marsh, Massachusetts. Twenty-five samples were collected at 28 centimeter intervals from the core in this Holocene coastal marsh. Based on stratigraphic control, the age of the core samples includes a time sequence extending back 4,600 years from the present. Analysis of the core stratigraphic units suggests the environment has essentially been a low energy estuarine system for the past 4,600 years. The 25 samples were also processed for pollen taxa present since 4,600 years B.P. A discriminant function analysis was used to test the floristic zonal similarity of the diagnostic taxa (Picea, Pinus, Carya, Tsuga, Quercus) from the core with those same taxa used to establish the floristic zones for the southern New England region. The results of the analysis demonstrated that 84% of the samples were correctly classified by floristic zone. Although the distribution of diagnostic taxa from this study is generally in agreement with the previously established floristic zones, the Tsuga taxa are present throughout the temporal sequence, suggesting the occurrence of a cooler climate regime for the sampling site since 4,600 years B.P. 相似文献
95.
96.
《African Journal of Marine Science》2013,35(3):491-499
This study provides one of the first quantitative assessments of a fish community within a pre-operational deep-water port system. Between September 2006 and September 2007 a total of 4 559 fish, representing 47 species and 27 different families, were caught within the Port of Ngqura, Africa's deepest port, in 1 713 h of shore-angling (2.3 fish angler?1 h?1) and 239 h of boat-based angling (2.8 fish angler?1 h?1). Catches included species representative of both estuarine and shore fisheries. The majority (83.0%) of species caught were marine and most were less than size-at-50% maturity (71.4%). The most abundantly caught species were dusky kob Argyrosomus japonicus (25.5%), elf Pomatomus saltatrix (24.9%), garrick Lichia amia (17.7%) and dusky sharks Carcharhinus obscurus (10.7%). Fish assemblages differed significantly (p < 0.05) between three habitats within the port: Dolosse, Quay Wall and Sandy Shore. The Dolosse habitat supported the greatest abundance (3.1 fish angler?1 h?1) and diversity (43) of fish species. The Port of Ngqura is thus functioning as an important habitat for both juvenile and adult fish. The diversity and abundance of fish suggests the potential use of ports and other artificial structures for enhancing local fisheries in South Africa. 相似文献
97.
J. Unno 《Australian Journal of Earth Sciences》2019,66(6):923-935
Ichnofossils, although small-scale geological features, can be of geoheritage significance. The Western Australian soldier crab (Mictyris occidentalis Unno 2008) presents an unusual and unique association between the crab and its ichnology because, as the species progresses through life, its behaviour becomes more complex and its traces commensurably more varied. The links between crab ichnology, life stage, behaviour, and environment are so direct that where traces are preserved they can be used to interpret fossil crab sizes, population structures, behaviour and paleo-environment. In this context the ichnofossils comprise important paleo-ecological and paleo-environmental indicators. Middle Holocene soldier crab ichnofossils occur in 5000 year-old beach rock at Port Hedland, Western Australia. The ichnofossils include rosettes, pustules, pellet-roofed tunnels, back-filled burrows and swirl lamination, air cavities and tidal-current-degraded discard pellets. They provide information on soldier crab population sizes and behaviour, and the nature of the environment along middle Holocene shores. The ichnofossils are of geoheritage significance in their own right for the paleontological and paleo-environmental information they present, however, given the rarity of their preservation, and the location of well-developed beach rock largely restricted to the arid Pilbara Coast, these ichnofossils are an uncommon and significant geological tool for use in paleo-environmental, paleo-ecological and paleoclimate reconstructions. They are of geoheritage significance because of their diagnostic signatures and rarity of occurrence. The limitations of current classifications of traces and ichnofossils, owing to restricted definition of terms, are highlighted by these ichnofossils as several ichnological products in the complex range of soldier crab traces are not possible to classify. 相似文献
98.
综合物流时代的到来与港口功能的演变 总被引:7,自引:1,他引:7
综合物流是现代社会对运输发展的客观要求,它要求实现运输的全球化、信息化、高效化和门对门,综合物流因此也改变了传统的运输组织体系。港口作为综合物流时代连接海向腹地和陆向腹地的重要节点,在整个物流体系中有着非常重要的地位,而综合物流也加快了港口功能的演变,现代港口已经成为国际物流体系的一个重要的节点。最后论述了如何加快我国物流体系及集装箱港口的建设。 相似文献
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