长江口深水航道治理一期工程实施对北槽拦门沙的影响

介绍了长江口拦门沙发育及其特点和北槽航道拦门沙形成机理，利用长江口深水航道治理一期工程实施后的地形资料分析治理工程对北槽航道拦门沙影响。结果表明：治理工程建成后，增加了主槽流速，减少了航道回淤，打通北槽航道拦门沙，增加了航道水深，治理工程效果明显。     

汕头港外拦门沙整治技术和功效

汕头港外拦门沙是制约该港进一步发展的主要障碍,在对工程海域环境泥沙论证基础上,进一步对工程泥沙问题进行论证和预报,如拦门沙整治后的演变趋,开挖航道的回淤和导流 沙功效等。工程实施期间及完工后进行多年的现场跟踪观测表明,各项工程泥沙问题的预报均获得良好的印证,本文还介绍了外拉门沙整治技术方面的经验,包括运用单导堤改变工程海域水沙营运动力局和泥沙输移方向,导堤的长度和高度,沿堤流和顶冲流的整治,航道工     

广利河口航道整治研究

广利河口拦门沙航道水深较浅,用双导堤结合航道疏浚进行整治。通过潮流定床模型试验对航道走向、导堤间距、高程、水流流态和堤头布置等进行了方案优化,同时采用局部动床定性试验进行了验证。推荐方案沿程流速、流态分布合理,基本能维持航道水深并满足设计船型的航行条件,可供类似河口治理参考。     

河口拦门沙航道整治方案及效果研究

在分析射阳港拦门沙航道一期整治工程建设后航道回淤特征的基础上,通过潮流泥沙数学模型分析研究了二期不同整治方案建设后的水流、含沙量及淤积分布特征,论证了不同方案的整治效果。研究表明:现状条件下由于导堤为潜堤,受越堤水流、口门回流等影响,一期工程建设后航道沿程普遍淤积。在一期导堤的基础上将导堤加高后有利于减小口门段航道淤积;将导堤延长后,淤积最严重的部位年淤强度有所减小,但在新的口门附近航道淤积仍然较严重;将口门宽度缩窄后,口门附近的淤积强度有所减小,但幅度有限;在航道内增加丁坝后,口门段泥沙淤积强度有所减小,但对改善中段航道淤积有限。     

长江口拦门沙深水入海航道整治工程的研究

随着国民经济的发展和上海浦东新开发区的发展，长江口深水入海航道的选择与治理，已越来越多地引起人们的关注，长江口深水入海航道的选择基本上可以分为避开拦门沙和不避开拦门沙两类。本文根据长江河口的发育模式、河口延伸、汊道演变的规律、汊道的形态与水力条件，提出长江口拦门沙深水入海航道整治规划，近期以北槽－８ｍ航槽为宜，远期可逐步开发至－１２．５ｍ     

磨刀门拦门沙区域近期地貌演变和航道整治研究

应用近几年的水文和地形实测资料,研究了磨刀门拦门沙区域近期的动力和地貌演变特点.近期地貌演变的主要特点为:深槽外移扩展,一主一支分汊明显;拦门沙内坡冲刷外移,外坡变化不大,纵向宽度变窄;拦门沙西区淤积,拦门沙中心区和拦门沙东区冲刷;地貌轴线总体向南和西南方向偏转.从水动力和地貌演变的角度来看,磨刀门拦门沙区域航道整治应关注下列问题:1)注意河口性质的变化,着重解决径流输沙,波流共同输沙这两个主要问题;2)在工程布置中,应与口门外动力场的特点和地貌演变的总体趋势相适应,以建设双导堤为宜;3)西汊、东汊均是可选择的航线,从综合因素考虑宜选择西汊;4)注重河口分汊的自然规律,注意保护东支汊;5)注意稳定拦门沙中心区.     

广利河口拦门沙的沉积特征与冲淤过程的研究

为给广利河口航道的建设提供科学依据,通过对研究区现场调查,查明了广利河口拦门沙水动力特征、海底地形、底质特征和地层垂向分布特征。在进行沉积物分析与历史资料对比分析的基础上,探讨了拦门沙体的沉积特征和冲淤过程。分析认为,广利河口拦门沙是在浅海-潮坪基础上接受广利河、支脉河和溢洪河携运泥沙堆积而成,海岸滩涂沉积物和黄河口水下岸坡物质对拦门沙的发育也产生了一定的影响。在河流和海洋动力作用的改造下,现在拦门沙基本进入冲淤平衡时期。但近期由于人工因素的影响,拦门沙顶出现暂时的淤积。研究结果还表明：拦门沙体北侧水动力作用明显强于南侧,航道设计为东偏南较好。     

广利港口拦门沙航道开挖后淤积强度预测

广利港口拦门沙的发育使得对航道疏浚的要求日益迫切，而疏浚后海底地形的改变会导致水动力条件的变化而产生泥沙回淤。本文利用已得的数据资料以及数值模拟后的数据资料进行了回淤强度的预算，并据此对航道疏浚后每年的清淤量提出了合理的建议。     

长江口深水航道整治工程不同阶段北槽河床冲淤特征的动力机制分析

本文使用数学模型的方法,探讨不同工程阶段(1998年1月至2008年2月)北槽河床冲淤特征的动力机制。应用Delft3D模型建立了精度较高的长江口～北槽三维嵌套流场模型,为分析整治工程对北槽河床冲淤的影响,设计了4个数值试验来计算不同工程节点时北槽海域的流场分析,分别采用相同的外部驱动力(洪季)和不同工程节点的北槽地形与工程配置。通过比较不同工程节点的潮周期平均流场的平面分布、典型横断面分布和航道剖面分布及变化,发现:随着导堤、丁坝工程的建设,新建导堤和丁坝对应区段的主槽水动力显著增强,可见"双导堤+丁坝群"的束流效果明显;新建坝田,受导堤、丁坝影响水动力急剧减弱。不同工程阶段影响下,北槽海域水动力的"强弱变化"分布与同期河床"冲淤变化"格局基本吻合,因此,深水航道整治工程阶段影响下的水动力强弱变化是引发北槽河床冲淤变化的主要动力因素。     

航道工程作用下福姜沙水道滩槽演变特性及对水沙过程响应的数值研究

福姜沙水道是长江南京以下12.5m深水航道重点治理河段。航道工程实施后,仍需进行疏浚维护保障航道畅通。为了探究航道工程作用下福姜沙水道的滩槽演变特征,并进一步研究其对水沙过程的响应关系,采用基于Hybrid LTS/GMaTS方法的平面二维水—沙—床耦合数学模型进行了数值模拟研究。Hybrid LTS/GMaTS方法在不损失模型计算精度的前提下大幅度提高了计算效率。研究结果表明：1)水动力作用是洲滩变形的主要动力,体现在洲滩整体冲淤和局部形态改变两方面;2)航道工程作用下,福中水道入口处水动力条件明显改善,各特征流量级下均呈现刷深趋势,航道中段呈现“洪冲枯淤”的冲淤特征,主流被归顺在深槽内,且随着流量增长深槽向南摆动;3)边心滩演变和水动力作用共同影响福北水道航道冲淤变化,航道工程作用下靖江边滩、双涧沙沙舌、福北水道的滩槽演变关系和对径流特征响应过程发生根本性变化。对水道整体而言,航槽回淤现象得到显著改善,然而受到洲滩演变和局部水动力减弱的不利影响,福北水道入口处航道条件发生恶化。     

Model of the post-Cenozoic evolution of the cryolithozone of the shelf of the western part of the Laptev Sea

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.     

Investigation of the mechanism of the long-term evolution of the carbon cycle in the ecosystem of the Sevastopol bay

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.     

Contemporary state of the investigation of the influence of the discharge of rivers on the hydrologic structure of the Black Sea

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     

Modelling of the ecosystem of the Black-Sea shelf zone near the estuary of the Danube

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     

Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east

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.     

Dynamics of the ice cover and peculiarities of the ice transportation of the sediments at the tidal flats of the Kandalaksha Gulf of the White Sea

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.     

Parameters of the sediments of the deep-water basin of the Black Sea

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.     

Variability of the nutrient runoff of the rivers of the Arctic Basin

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.     

A model of the dynamics of the ecosystem of the Sea of Azov

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     

On the Relationship between the Characteristics of the Annual Variations of the Virtual Height of the Ionospheric Sporadic E Layer with the Seasonal Rearrangements of the Stratomesospheric Circulation

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...