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1.
三门湾海域水波共振现象较为显著,容易引发海洋灾害。针对三门湾这一典型半封闭海湾,分别从理论推导和数值模拟两方面研究了三门湾的共振周期。研究发现:理论推导结果可以用于对海湾整体共振周期的粗略估计,数值模拟结果更加精确,也能充分反映海湾内不同水域的共振特征。数值模拟结果表明,三门湾内各水域普遍存在3~4个共振周期模态,湾内各水道第一模态和第三模态共振周期数值解与理论值较为接近,石浦水道与外海相联通,共振周期不显著。三门湾内各水域共振周期第一模态对应的振幅最大,然后依次递减,但湾顶的青山港、蛇蟠水道第二模态共振周期及对应的振幅值与第一模态相差较小,基本呈现双峰结构。共振振幅由湾外向三门湾顶部逐渐增加,尤其是湾顶处振幅增益比较显著。通过本研究可以为三门湾的防灾减灾提供科学依据。 相似文献
2.
南海海啸在泰国湾海域的共振响应 总被引：1，自引：1，他引：0
马尼拉海沟具备引发地震海啸的条件,是南中国海主要的潜在海啸发生区。南中国海西南部泰国湾海域和纳土纳海域地形复杂、多独立的半封闭水域,海啸波极易在该区域形成水波共振,加剧其灾害影响。采用COMCOT海啸模型模拟了马尼拉海沟断裂带发生9.3级地震时引发海啸的长时间传播过程,并基于水波共振理论分析其在不同尺度下的共振特性。结果表明,海啸波在曼谷湾至邦加—勿里洞岛间引起了明显的纵向第一、二模态(3 360.0 min、1 440.0 min)水波共振,在泰国湾至邦加—勿里洞岛之间引起了明显的纵向第二、三、四模态(775.4 min、560.0 min、373.3 min)共振,而在泰国湾至印度尼西亚沿岸引起了明显的纵向第二、三、五、七模态(1 008.0 min、630.0 min、373.3 min、252.0 min)水波共振。此外,海啸波不仅在泰国湾引起了明显的纵向第一、三、四模态(560. 0 min、252. 0 min、179. 4 min)共振,还在其横向出现了明显的第一、二、三模态(480.0 min、252.0 min、179.4 min)共振。 相似文献
3.
1981年8月中旬,我乘“潘德拉Ⅱ”号到圣劳伦斯湾,参加了贝德福德海洋研究所第8151—52航次用下潜器PiscesⅣ号(派塞斯)进行“在自然水环境中悬移质泥沙的物理行迳”的专题调查。 圣劳伦斯湾位于加拿大东部,界于纽芬兰、魁北克、新不伦瑞克与新斯科舍省之间,系沿NE向的圣劳伦斯河支谷与NW向的主河谷,由张裂断陷而成的一个内陆海湾。NE与NW 相似文献
4.
对海洋潮汐共振的理论、方法和各海域共振周期的估算进行了综述。对共振的经典理论介绍了阻尼简谐振动、1/4波长共振和Helmholtz共振的基本理论和共振周期的计算公式。对实际海域共振的数值计算方法方面介绍了Platzman简正模态方法和Webb边值方法的原理。还对这些理论和方法在估计近岸和大洋各海域共振周期中的应用工作做了综合性介绍。在国外海域中,共振特征最明显的是位于加拿大的芬迪湾。在中国近海,许多研究认为北部湾较强的全日潮、仁川湾和台湾海峡较强的半日潮均与海湾共振有关,其中北部湾的共振特征最为明显。 相似文献
5.
以三门湾为例,基于经验模态分解方法 (EMD)将原始风暴潮增水过程进行分解,并对各个子模态进行能量谱分析,研究每种波动对应的生成机制。结果表明:半封闭海湾内的风暴潮增水较为严重,造成三门湾内强增水的台风为三门湾南侧的西北向登陆台风。EMD分解结果显示三门湾内的风暴潮增水包含6 h,12 h,20 h左右的波动,其中6 h左右的波动来源于海湾共振,共振的频率是由海湾的形状、水深等固有性质所决定的。12 h的波动是由于天文潮与风暴潮耦合作用导致,20 h左右的波动是由于台风移动过程中外海波动的传入。结果表明EMD方法为风暴潮波动增水特征的精细认知提供了一种新的思路和方法,可以加深对海湾内风暴潮波动增水特征的研究。 相似文献
6.
本文基于TELEMAC-2D模型建立太平洋区域海啸传播模型,模拟2011年日本“3·11”海啸事件下海啸波的传播。使用实测数据对该模型进行验证,在模型验证良好的基础上分析日本“3·11”海啸事件对乐清湾的影响。通过频谱分析得到“3·11”海啸激发的乐清湾内240、180和103 min这3个主导模态的幅值及其相位。通过白噪声实验对乐清湾的固有共振特征进行估算,进一步支持了乐清湾在上述3个模态发生共振这一结论。白噪声实验还表明,海啸等海洋灾害发生时会在乐清湾湾顶及湾口处产生较大的增水,该结论对乐清湾内海洋灾害风险防范具有指导意义。 相似文献
7.
龙口湾大振幅假潮形成的数值模拟 总被引：1，自引：0，他引：1
龙口湾是出现假潮比较显著的海湾之一。据统计,１９７２～１９８１年,平均每年出现６次〉４０ｃｍ的振动,其中１９８０年９月１日观测到水位振动的最大振幅达２９３ｃｍ,同日的气压波也有７ｈＰａ的起伏。用数值模拟方法,初步探讨了气压扰动与１９８０年９月１日 在龙口湾观测到的假潮之间的定量关系,证实,在龙口湾中出现的大振幅假潮的确是由于移动气压波扰动激起湾外长波传入湾内发生共振所引起的。直接由气压波扰动很难引 相似文献
8.
利用6期卫星影像数据,提取出1981—2014年间不同时期台州湾大陆海岸线空间位置、长度及岸线属性等信息。通过Arcgis空间分析,以各时期岸线长度、岸线属性和陆域增长面积为数量指标对海岸线的时空变迁过程进行反演,并对台州湾大陆岸线变迁的特点和主要驱动力进行分析。研究表明,研究期台州湾大陆岸线变化显著,岸线长度增加17.5km,增幅约13.5%,受围垦工程"裁弯取直"效应影响,人工岸线在2000—2009年大幅减少,呈震荡增长趋势;自然岸线长度整体呈缓慢减少趋势,然而,由于大规模连岛围垦工程使得自然岸线在2009—2014年增长10.8km。由岸线变迁引起的陆域增长面积约177km2,海岸变迁的主要驱动力为台州湾海域大规模的围垦造陆工程。长期以来,以滩涂及近海优良自然条件为依托进行的围垦填海工程是台州湾岸线逐年向海推进的主导因素。 相似文献
9.
10.
钦州湾近似于一个葫芦海湾。它主要由三大部分组成,即外湾、内湾、湾颈。外湾是钦州湾的主体部分,指湾口至湾颈的区域;湾颈指龙门港附近;内湾指茅尾海一带。其中外湾湾口处最宽,可达28公里。湾颈处最窄,狭窄处仅1.3公里。内湾宽约13—18公里。整个海湾平均水深约10米。 相似文献
11.
亚丁湾护航任务的常态化对海军航海保障工作的发展提出了新的要求,着重探讨护航任务中航海保障的相关情况,总结护航任务中航海保障的经验,提出护航任务中存在的不足以及展望,对今后的护航行动具有十分重要的借鉴意义。 相似文献
12.
Fatemeh Amini‐Yekta Mohammad Reza Shokri Abdolvahab Maghsoudlou Hassan Rajabi‐Maham 《Marine Ecology》2019,40(3)
Variations in environmental factors can alter the species distribution pattern in intertidal rocky shores. The Persian Gulf (PG) and the Gulf of Oman (GO) vary substantially with respect to environmental and oceanographic conditions. The abundance and biodiversity of intertidal rocky gastropods in five locations across the northern PG and the GO were compared, and the environmental variables underlying the distribution pattern of these organisms were investigated. A total of 67 gastropod species were identified. The largest average density (294 ind./m2) and diversity (N = 43) for gastropods occurred in the Hotel Lipar station (LIP) located in Chabahar Bay in the GO. Clypeomorus bifasciata (107.43 ind./m2) followed by Cerithium caeruleum (94.67 ind./m2) were the most abundant species. Planaxis sulcatus and Siphonaria spp. occurred in all locations during both sampling occasions. Species richness and abundance of gastropods showed significant differences between LIP and remaining locations. A significant difference was found in assemblage structure across locations. In general, the species richness and density in the locations at GO were significantly larger than those locations in the PG, suggesting that the harsh environmental condition in the PG might be the forcing factor for this diminish. Distinct grouping was observed in both assemblage structure and species composition between locations in the PG and the GO. The spatial and temporal distribution patterns of gastropods assemblages were significantly correlated with variation in salinity and substrate rugosity. 相似文献
13.
Abstract. New data on the planktonic diatoms from the Gulf of Naples are presented together with those from the literature. Information is given on abundances, seasonal cycles and distributions of 183 taxa, including species, varieties and forms. 相似文献
14.
Mohamed M. El-Komi 《海洋学报(英文版)》2008,27(2):55-80
The biogeography of macrobenthic communities with large-scale differences in species distribution and abundance was studied along the eastern and western coastal regions of the Gulf of Suez to indicate biodiversity of benthos in relation to the prevailing environmental conditions. In general, benthos have a wide variety of species of mainly polychaet worms, crustaceans, bivalves, and other bottom invertebrates living in burrows in/or on the sediment surface. Coastal development clearly affects the ecosystem after the construction of coastal projects. The highest values of benthic diversity, evenness, richness and dominance are found at the Gulf of Suez （WG 1, WG 3）, Ras Gharib （WG 7, WG 8） and Ras Shukier （WG 9a） by contrast to others. The abundance of macrobenthic organsims along the coasts of Gulf of Suez can be arranged in the following sequence： other groups （34%） greater than crustaceans （25%） greater than polychaetes （22%） greater than molluscs （17%） greater than echinoderms （2%）. The biomass of benthic assemblages at different sampling sites can also be ranked as follows： echinoderms （52%） greater than molluscs （27%） greater than crustaceans （16%） greater than polychaetes （2%） greater than other groups （3%）. Some benthic groups or species indicated a distinctive correlation to pollution sources in the marine ecosystem which obviously increased in the coastal areas due to the extension of the coastal development. These activities needed regular information to establish database for the biology and distribution of marine benthic communities. The density and diversity of benthos are significantly affected by eutrophication at Ain Sukhna, whereas the benthos in the open Gulf of Suez do not seem to be adversely affected by pollution. 相似文献
15.
The ecology of the family Pinnidae was studied by sampling three pinnid species from 36 sampling sites across four different microhabitats in the Gulf of Thailand. The species spatial distributions were mostly uniform, with some populations having random distributions. Species abundances differed between sandy and coral habitats according to non-metric multi-dimension scaling analyses. Although the Gulf of Thailand is a relatively small geographic area, habitats are varied enough to provide variable shell densities. Small islands are important distribution areas, and coral reefs provide both direct and indirect shelter which support high abundances, densities and increased shell size. The highest density was recorded in sand beds within coral reefs. Low density and small shell size in sand beaches might be related to high mortality in shallow water or to adaptations for survival in shallow waters. A clear correlation between sediment composition and species abundance was found in Pinna atropurpurea; abundance increased with the sand content of the sediment. For P. deltodes, abundance increased as the rock fraction of the sediment increased. These results suggest that adaptations in Pinnidae, such as shell size, shell morphology, and the exposure of the shell above the sediment-water interface, are responses for survival in different habitats. 相似文献
16.
Benthic Denitrification in the Gulf of Bothnia 总被引：1，自引：0，他引：1
Denitrification was measured over an 8-month period in the Bothnian Bay and the Bothnian Sea, the two northernmost basins of the Baltic Sea. The recorded rates varied between 0 and 0·94 mmol N m−2day−1. In the Bothnian Sea, a seasonal pattern could be discerned with high rates in spring, no rate in summer and a moderate rate in winter. In the Bothnian Bay, no such seasonality was observed. It is suggested that denitrification in the Gulf of Bothnia is regulated by sediment nitrification. Calculation of annual mean rates of denitrification gave that the amount of nitrogen consumed by denitrification corresponded to 1·45×104tons N year−1for the Bothnian Bay and 3·45×104tons N year−1for the Bothnian Sea. A comparison with total N input (river runoff, point sources and atmospheric deposition) to the two basins showed that the proportion of N removed through denitrification amounted to 23% for the Bothnian Bay and 31% for the Bothnian Sea. 相似文献
17.
Jessica L. Bangma Richard L. Haedrich 《Deep Sea Research Part II: Topical Studies in Oceanography》2008,55(24-26):2594
We quantify the similarity of the Gulf of Mexico mesopelagic fish fauna to that in adjacent oceanic regions, the Venezuelan and Colombian Basins of the Caribbean Sea and the North and South Sargasso Seas. The South Sargasso and Colombian are the least similar of the areas in terms of their faunal composition, and the Venezuelan and Colombian Basins are the most similar. The Gulf fauna lies somewhere in between, and is a composite of that in the Sargasso and Caribbean Seas. The Gulf of Mexico displays the greatest abundance, biomass and richness (S=140 species), and is an intermediate in evenness (J=0.66) and percent endemism (7.1%). Our findings support the view that the centrally located Gulf is an oceanic ecotone between the Atlantic Tropical and Subtropical faunal regions. 相似文献
18.
Tetsuo Yanagi Suhendar I Sachoemar Toshiyuki Takao Shunji Fujiwara 《Journal of Oceanography》2001,57(4):461-470
Intensive hydrographic observations were carried out in the western part of the Gulf of Thailand and the east coastal sea
of Peninsular Malaysia in September 1995 and April–May 1996. The characteristics of seasonal variation of oceanic condition
in that area are discussed basis of an analysis of observed water temperature, salinity and density distributions in these
cruises and NAGA cruises (Yanagi and Takao, 1998a). Stratification is most developed in March–May mainly due to large sea
surface heating and weak sea surface wind, which weakened until September–October, vanishing in December–January. The horizontal
distribution of bottom cold, saline and heavy water masses, which are found during the stratified season, is governed by the
tidal mixing and the water depth. Water exchange between the Gulf of Thailand and the South China Sea becomes large in March–May
due to a coupled effect of the intensified estuarine circulation and the Ekman transport by the southwest monsoon.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
19.
A Study on Residual Flow in the Gulf of Tongking 总被引：2，自引：0，他引：2
On the basis of observations of water temperature, salinity and wind during winter (December to following February) and summer (June to August) in the Gulf of Tongking, a robust diagnostic three-dimensional model has established that reveals the seasonal variation in residual flow, including wind-driven current, density-driven current and tide-induced residual current. It is shown that in the Gulf of Tongking the wind-driven current plays the most important role in the seasonal variation of residual flow field. Due to strong NE monsoon (9 m/s) during winter the residual flow (reaches 30 cm/s) is stronger than that in summer. At the surface the residual flow direction during winter is basically westward or southwestward, while during summer it is almost reversed. 相似文献