首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 966 毫秒
1.
岬湾海岸中一般在岬角的右侧与左侧(面向大海方向)分别发育顺时针与逆时针涡流。这些涡流的存在对泥沙输运、海底地形演变、污染物扩散等都具有重要影响。而在海洋中岛屿的存在将产生局部的岛后尾流。如岛屿与岬角距离较近,岛后尾流可能与岬角涡旋相互作用,反之则相互影响较小。本文以海南岛铺前湾为例,研究在岬湾海岸中湾口处的人工岛建设对湾内涡旋的影响,并进一步分析人工岛建设对整个海湾海底冲淤变化的效应。本项研究主要采用COAWST模型进行研究。结果表明,大潮期在海湾内发育大范围的顺时针涡旋,小潮期涡旋发育不明显,以东向余流为主。人工岛建设并未影响整个海湾的涡旋结构,但人工岛分隔了湾内顺时针涡旋,且在周围产生局部的逆时针与顺时针涡旋。海底冲淤变化的基本格局为湾内以淤积为主,人工岛建设加强了这种趋势,但在人工岛与岸线之间的狭窄通道内,海底出现冲刷。本项研究对岬湾海岸的科学开发管理具有一定意义。  相似文献   

2.
大连湾保守污染物迁移三维模型及应用   总被引:1,自引:0,他引:1  
王平  张宁川 《海洋通报》2013,32(3):265-274
采用基于有限体积法和非结构化网格的三维潮流模型,同时耦合拉格朗日粒子追踪模型和保守污染物输运扩散模 型。模拟了大连湾内的水动力变化、潮致余流场分布、保守污染物的输移和特征粒子的运动轨迹;同时研究了不同人工岛对 湾内污染物迁移的影响。模拟的潮流场与实测数据吻合较好。结果表明:湾内潮致余流呈顺时针半涡形态,湾口潮致余流呈 NE 方向;湾内保守污染物主要随潮致余流的方向而迁移,湾口的迁移扩散快于湾中,湾内北部的污染物能较快扩散到湾外, 湾内南部的污染物易在湾底滞留,各个子湾内的污染物不宜扩散出来;两种方案人工岛均会降低臭水套湾和香水套湾的自净 能力,且方案2 比方案1 的影响大;而对红土堆子湾方案1的影响比方案2大,且方案2 能改善其水质情况。  相似文献   

3.
浙江三门湾宁海下洋涂围垦工程投入养殖后排放的养殖污水将对周边水环境产生的影响预测是该项目环境评价的重要内容。在海湾潮流动力模拟的基础上,建立了污染物对流扩散的数学模型,用以预测养殖污水排放后的扩散范围及强度大小,为环境评价提供科学依椐。  相似文献   

4.
近年来,人工岛被广泛应用于沿海地区的填海造陆工程以快速获得优质土地,但大面积的人工岛建设会对近岸海底沉积物的分布模式及输运过程产生重要影响.为认识人工岛建设后沉积物变化与运移特征,本文以南海明珠人工岛对海口湾的影响为例,根据人工岛建设前后分别在海口湾近岸采集的底质表层沉积物分析了沉积物特征变化,结合沉积动力分析及粒径趋...  相似文献   

5.
孙涛  陶建华 《海洋学报》2003,25(3):104-112
在近岸缓坡浅水海岸,波浪破碎产生沿岸流是近岸海域流场的重要组成部分,它对污染物输移扩散规律的影响重大,在高阶近似抛物化缓坡方程求解大面积波浪场基础上,建立了波浪作用下污染物输移扩散数学模型.计算结果与不同坡度均匀斜坡地形上具有不同波高、周期的规则波及不规则波浪作用下污染物输移扩散实验结果进行了比较,分析了各种因素对波浪作用下沿岸流分布规律影响,所得结论认为地形坡度及入射波高对污染物输移扩散的影响较大,波浪作用将使缓坡海滩上污染物的输移扩散平行岸线方向.  相似文献   

6.
基于污水处理厂削减污染物的特性探讨了在受直排污水影响海区预测污水处理厂建设后对海洋环境影响时,采用排放口入海污染物的减少量作为扩散模型的源项。并以烟台套子湾污水处理厂二级扩建工程为例介绍此方法的运用,结果符合客观实际,能反映出了污水处理厂的建设对水环境的改善,表明源项选取正确,对开展污水处理厂的海洋环境影响评价工作具有一定的实用和参考价值。  相似文献   

7.
江苏新月形人工岛建设探讨   总被引:1,自引:0,他引:1       下载免费PDF全文
21世纪,人工岛为世界许多沿海国家更为广泛的建设和利用.江苏沿海开发已经拉开序幕,并在南通洋口太阳沙建造了一座人工岛.人工岛对于江苏沿海地区发展和海洋开发有着极其重要的作用,但是由于巨大的投资和浩大的工程,使许多地区对人工岛望而却步.通过积极探索新月形淤泥基人工岛建设,利用人工设施对于自然力和自然资源的充分利用,即通过对风浪等自然力和江苏沿海丰富的泥沙资源合理利用,既从真正意义上实施江苏人工岛的常规化建设,也为江苏沿海实践新海洋型工业理论,发展节约资源、综合开发和集约发展提供了一条新的途径.  相似文献   

8.
离岸建设人工岛是围填海的重要方式之一。人工岛的建设势必改变工程区的水动力条件、泥沙输运格局与海岸演变状况。选取合理的平面布置方案,减少工程建设对海岸环境的负面影响,是人工岛建设能否成功的关键因素。以海南岛万宁日月湾人工岛建设为例,利用DELFT 3D模型系统,研究原场与不同平面布置方案后的波浪传播、波生流、泥沙输运与岸滩演变,探讨不同人工岛方案岛后形成连岛坝(Tombolo)或突出体(Salient)的可能性及泥沙淤积体积的大小,分析不同方案的优劣。研究表明,不同人工岛方案因为其大小、离岸距离及所处位置的差异,对岛后的波浪传播、波生流、泥沙输运与地形冲淤演变产生不同的影响。人工岛离岸距离越远、所处位置水深越大,人工岛在波峰线上的投影长度越短,形成连岛坝的可能性越小。  相似文献   

9.
龙口湾水动力特征及其对人工岛群建设的响应   总被引:1,自引:0,他引:1  
基于龙口湾及附近海域的水文实测资料,利用Mike21数学模型模拟了人工岛建设前后的潮流、波浪、纳潮量及水交换率等水动力特征,探讨了人工岛群建设对龙口湾水动力环境的影响。结果表明,人工岛建设显著改变了龙口湾潮流场特征及水体运动路径,湾内受到人工岛的阻挡,流速普遍减小,局部区域潮流运动形式由往复流变为旋转流,流向变化较大,余流形成多个涡旋;湾外由于堤头挑流作用导致局部区域流速增大且余流流速增大,潮流运动形式未发生明显改变。受人工岛的掩蔽作用,人工岛及附近区域的波浪有效波高普遍减小。龙口湾潮位出现北部最大潮差变小、南部最大潮差增大的格局,壅水作用导致人工岛内部水道潮差变化明显。人工岛建设直接占据了龙口湾海域面积,导致其纳潮量明显减小,水交换率呈现南部和北部增大、人工岛北侧以及内部水道减小的特征,人工岛造成的水动力环境的改变是影响水交换率变化的主要原因。人工岛群建设导致龙口湾内的潮流、波浪、纳潮量以及水交换等水动力特征减弱,是引起龙口湾水动力条件变化的根本因素。  相似文献   

10.
人工浮岛是人工岛的一种方式,在国外至少有千年之久的发展历史,国内外对于人工浮岛技术及应用已开展大量研究。本文概括了人工岛、人工浮岛定义及其分类,通过文献收集分析了国内外关于人工浮岛在环境改善、生态修复、景观改造、栖息地建造等方面的应用优势及相关的各种专利产品。国外人工浮岛在居住功能、环境改善和栖息地改造、景观改造等方面的成功经验值得我们学习,在利用人工浮岛技术向远海开发拓展、转移近岸海域海岛生态环境压力、建设海洋多功能平台,开展多元化开发利用等方面具有启发和前景,将其技术借鉴至海岸带水环境治理、生物岸线的改造、旅游规划等方面将对于促进海洋生态文明建设,利用新技术改善海域海岛生态环境具有重要意义。  相似文献   

11.
The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ~200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ~380 km from the coast at a depth of ~250 m above the sea level.  相似文献   

12.
We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative abundances of organic and inorganic carbon as an index of the carbon cycle stability.  相似文献   

13.
We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic regime of the sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

14.
We analyze the results of numerical calculations performed according to the three-dimensional interdisciplinary model of an ecological system of the Black-Sea shelf zone near the estuary of the Danube. The complete system of equations of hydrothermodynamics is solved together with transport equations of the advection-diffusion-reaction type used to describe the transformation of a substance (nitrogen) between the components of the characteristic vectors of the ecosystem: plankton, detritus, and biogenic elements (nitrates). We describe the distinctive features of the circumcontinental distribution of components obtained as a result of numerical experiments and present arguments for the conclusion that the ecosystem of the Danube estuary water area plays the role of a buffer zone between the press of the Danubian biogenic pollutions and the neighbouring areas of the shelf zone and open sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

15.
Ten years of semistationary studies of the interaction of the ice cover and the coastal relief of the Kandalakhsa Gulf in the White Sea allowed us to reveal the peculiarities of these processes in the warm and cold years and the mechanisms of the origination of ice forms, including ice tents, which govern the character of the tidal flats. Three dynamic fast ice zones are distinguished by their geomorphological location, morphology, and ice dynamics. The dependence of the mechanisms and volumes of the enrichment of the fast ice in the sediments on the coastal zone??s relief was established. At the coast of the Kindo Peninsula (Velikaya Salma Strait), the ice mostly contains fine-sandy sediments. Coarser sediments, including boulders, are occasional and frozen into the ice at the contact of the fast ice and the bottom. At the expense of the ice??s spreading by 4?C6 times in the warm years and 2?C4 times in the cold years, several thousand tons of sediments mostly from the tidal flat??s surface (100?C700 m3 from 1 km of coast in the wide tidal flats and <50 m3 on the steep coasts) are delivered to the water area.  相似文献   

16.
A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state.  相似文献   

17.
We use many-year archival observations of hydrologic and hydrobiologic state of the Sea of Azov for the identification of the structure of a model of its ecosystem. The ecosystem model, supplemented with expert estimates of bioresource consumption (fish reserve), contamination level, and possible ecologic fines for violation of the sea natural state, is formalized by the method of system dynamics. Hereat, the major part of influence functions is found in terms of observational data with application of self-organization algorithms. We also present the results of simulated experiments with the model of the ecosystem, which enable us to analyse scenarios of its behaviour under the influence of various external factors (wind, river discharge, water exchange with the Black Sea, etc.). Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

18.
Izvestiya, Atmospheric and Oceanic Physics - Analysis of the temporal variations of the virtual heights of the sporadic E layer (h?ES) determined from ionograms with increased accuracy (1...  相似文献   

19.
The methodology and the first results of the computations of the volumes, masses, and growth rates of the sedimentary body of the buried Black Sea basin are presented. Their temporal evolution reflects the regional paleogeodynamics, in particular, the reorientation of the vector of the relative movement of the Arabian and Eurasian lithospheric plates and the related intensification of their collision in the late Miocene-Pliocene.  相似文献   

20.
The spatiotemporal variability of the hydrochemical composition of the riverine runoff in nearmouth areas is presented using the example of selected rivers of the Arctic Basin. The temporal dynamics of the riverine nutrient runoff are mainly determined by the seasonal and interseasonal variations in the drainage basins. The spatial variations in the chemical composition of riverine waters in the near-mouth areas are mainly caused by the dynamics of the water flow and the river bed relief and, to a lesser degree, by biochemical processes. It is shown that the variations in the nutrient composition of the waters in near-mouth areas are comparable in magnitude to those at the river-sea geochemical barriers.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号