广西沿海水下地貌及其沉积物特征

本文在广西海岸带调查资料的基础上进行综合分析,论述了广西沿岸浅海水下三角洲、水下岸坡、古滨海平原和海底平原等水下地貌的形态特征及其展布规模,通过对各种地貌类型中的沉积物组成进行研究,阐述了沉积物的粒度、碎屑重矿物、微体古生物在各种地貌部位上的分布特征。     

人类活动对烟台附近海岸地貌演变的影响

依据野外调查与有关资料，在分析烟台附近自然条件下形成的海岸地貌特征的基础上，对近期人类活动对海岸地貌演变的影响进行了探讨，指出海岸带的开发与管理应重视人类活动对海岸地貌演变的影响。     

莱州湾海岸带遥感图象的地貌解译研究

本文采用光学图象增强方法和计算机数字图象处理技术,对菜州湾34幅卫片进行了图象处理及地学解译,结合地面资料,完成了有关图件36幅,包括:菜州湾海岸带地貌特征及其成因类型;菜州湾潮间带地貌分带及全新世海侵范围;黄河入海泥砂的扩散范围及强度分布;菜州湾岸线动态变化、岸滩稳定性等。遥感图象处理方法应用于海岸带地貌动态分析研究具有广阔前景。     

泉州湾海岸带地形地貌特征及控制因素

利用最新测深资料绘制了泉州湾地形图、地貌图,对海岸带地形地貌特征进行了详细的分析,表明泉州湾水深为0～20 m,等深线走向基本平行于海岸线,局部地形变化剧烈,地貌类型可分为潮间带地貌和海底地貌(水下岸坡),且呈滩槽(水道)相间展布的特征；认为地质构造、全新世海侵、现代水动力以及人类活动等内外营力的共同作用,控制了泉州湾...     

河北省海岸带浅滩水文和滦河口调查已完成

一九八四年底和一九八五年初,海洋局一所受河北省海岸带和海涂资源综合调查领导小组的委托,分别承担了河北省海岸带浅滩水文调查和滦河口调查两项任务。经过四次外业调查,取得了较完整的海洋动力、沉积和地貌等方面的资料,并通过内业工作,较系统地分析了河北省海岸带浅滩水动力特征和滦河口的水动力、沉积及地貌特征,探     

浙江海岸带文化资源形成的地貌环境因素分析

通过地貌因素对海岸带文化资源形成的作用进行分析,认为浙江海岸带文化资源形成过程中的地貌环境因素主要包含沿岸陆域地貌、岸滩地貌、海岸地貌的变迁和人类活动对地貌环境的作用4个方面,并在此基础上分析了各因素的影响机制。     

渤海地貌类型及分布特征

渤海属于中国封闭的陆架浅海,主要由辽东湾、渤海湾、莱州湾、渤中洼地以及渤海海峡组成,总称"三湾一峡一盆地",通过对相关地区区域地质调查所获取资料的整理和研究,同时结合前人的工作成果,对渤海的地貌类型进行了重新的厘定和分类,将渤海分为三级地貌类型8种,四级地貌形态4种。同时根据表层沉积物的分布特征,并且结合渤海沿岸河流的输沙、沿岸流的作用及波浪对海岸带的影响,对于渤海不同地貌类型分布特征进行了圈定。     

海岸带地貌调查与制图

海岸带是内、外和陆、海动力共同作用的产物,地貌类型复杂多样.介绍了岩石质、沙砾质、粉砂淤泥质和生物海岸的各种地貌特征、动力机理、演化趋势和主要辨认标志;在总结数十年实际调查经验的基础上,结合历次调查规程提出了海岸带野外地貌调查的主要内容和要领,并解释了地貌成果图的编制过程.     

白沙口海岸带泥沙运动和地貌演变

近几十年来，许多沿海国家都开展了大规模的海岸带调查工作，并对海岸带的泥沙运动和地貌演变的某些规律进行了深人研究。但是，对于有潮海滩不同地貌部位上的泥沙运动特征及其控制因素，以及不同地貌部位上，反映泥沙群体运动结果的堆积体运动规律等的现场调查，至今报道不多。实际上，有潮海滩并非单调一致，海滩不同地貌部位上的泥沙运动规律和地貌发育规律，都有极大的、甚至本质上的差异。研究这些差异性，对于我们深入了解海岸带泥沙运动和地貌演变的规律，是有所裨益的。 白沙口位于山东半岛南岸，五垒岛湾之西(见图1) ，湾口朝南，面对黄海。湾内堆积地貌发育。一条巨大的湾口沙咀，自常家庄南岬角向西延伸，逼近海阳所南部的角滩。沙咀的北面为泻湖，白沙滩河注入其中。所谓白沙口，实指泻湖的出口，也为一潮汐通道。由于陆源物质长期倾泻入海，出口处岸线呈扇形向海突出，形成白沙口潮汐三角洲。退潮后，三角洲上一片白沙，沙咀、沙洲等堆积地貌非常发育。它们在海浪、潮流，和河流径流等各种动力因素的交互作用下，活动性很强，其位置变化无常，给航运和水工建筑等带来许多困难。1971-1974年，中国科学院海洋研究所和山东省水文总站协作，在本区进行了系统调查，曾写了专门调查报告。本文试图根据其中的部分现场观测资料，对本区海岸带泥沙运动和地貌演变的一般特征、差异性，及其与动力因素之间的关系等问题进行初步探讨。     

河北省海岸带浅滩海域潮流及余流分析

河北省海岸带浅滩海域系指山海关石河口至黄骅县狼砣子一带,水深-2米以浅的海域,海岸线长约500公里。滩涂宽窄不一、地貌形态复杂,塑造这种海岸地貌的主要动力之一,是潮流和余流。因此,调查研究海岸带浅滩海域的水流特征,对开发利用海岸带的资源,以及开展浅滩海域沉积动力学的研究,都具有十分重要的意义。     

Morphology and internal architecture of a banner bank off Chengshan Headland, Shandong Peninsula

A banner bank off the north coast of the Chengshan Headland,Shandong Peninsula,has been described on the basis of echo sounder bathymetry,side-scan sonar and high-resolution seismic data sets.The bank is in NWW direction,approximately parallel to the coastline.The bank consists of sandy silt or clayed silt.Sand waves and megaripples are observed on the north side,which result from strong tidal currents around the headland and storm waves in winter.These bed forms indicate that the bank is influenced by the modern hydrodynamics.The bank is separated from the coast and Holocene subaqueous clinoform around the Shandong Peninsula in its east part.High-resolution seismic profiles reveal that the bank was formed during two periods:the earlier seismic unit Ua,and later seismic units Ub and Uc which overlays Ua with erosional surfaces on its south side and north side,respectively.As comparing with the clinoform,the bank has a different internal architecture.In the west of the bank,however,topography and surface sediment characteristics suggest that the bank links to the clinoform.The authors propose that seismic Ua is a residual part of early clinoform deposit.After the sediments in the north and south of Ua were eroded by strong currents,the Ub and Uc started to deposit probably by a complex hydrodynamic process.These results provide new insights into the evolution of the bank and its relation with the Holocene subqueous clinoform.     

黄骅港地区潮滩过程与港口选址

对黄骅地区潮滩过程的基本特征进行了讨论,结果表明,该区潮滩发育主要受黄河泥沙的控制,黄河从本区或其附近入海期间是潮滩迅速淤涨期,当黄河远离本区时,潮滩便开始退缩进入调整期。目前本区潮滩过程的主要物质是潮滩本身的沉积物。漳卫新河的来沙是本区的主要物源。本潮滩的潮下带宽达9km以上,破波带外界在约4．0m水深处,港址选在泥沙活跃的破波带内是值得商榷的。建议港口建设应尽量避开破波带．     

潮滩动态变化预测研究

利用卫星图像识别技术和潮汐数值模拟方法，反演沿岸潮滩高程分布；并在此基础上利用计算机技术和潮汐预报技术实现了无法获取实测地形和潮汐水位的滩涂地点的潮滩水深变化的动态预测。     

渗流与侧向流共同作用下的潮沟边壁侵蚀研究进展

潮沟的边壁侵蚀可以分为水流作用下的边壁冲刷与土块重力作用下的边壁崩塌。前人研究表明,水流流速、水压及土体干密度等因素均对底床冲刷率有显著影响,然而侧向边壁的冲刷率量测以及相关影响因素问题亟待解决。前人较多关注侧向流对于边壁崩塌的影响,而对渗流作用以及渗流与侧向流在边壁侵蚀过程中的共同作用研究较少。近期研究表明,渗流已成为边壁侵蚀过程中的重要一环。因此,渗流与侧向流不同动力作用下,边壁侵蚀的差异性和相似性,以及两种动力共同作用下的侵蚀机制仍待进一步探究。     

现代辽河三角洲潮流沉积

运用钻探和浅地层探测等获得的最新调查资料,对全新世以来辽河三角洲潮流沉积进行了研究。研究区10m深度内的地层主要包括潮滩相、潮道相和浅海相沉积,其下为古三角洲相。潮滩相沉积物以砂和粉砂为主,分选中等,跳跃和悬浮组分各占50%左右;浅海相和潮道相沉积物主要为软弱的黏土质粉砂和粉砂质黏土,以悬浮组分为主。全新世以来至1896年,研究区为古辽河与古大凌河、绕阳河复合三角洲之间的小海湾。1896年双台子河分洪以后,盖州滩等潮滩形成并快速发育,1969年建闸后,入海径流量不断减小,潮道趋于淤积充填。     

东海陆架西北部地貌分类及沉积环境演变研究

根据多次海洋调查的多波束、表层沉积物资料及中法合作海洋地质调查的浅地层剖面资料,对东海陆架西北部的地貌进行详细分类,探讨该区环境演化规律。分析结果表明,该区存在潮流沙脊,潮流冲刷槽、暗礁等多种地貌形态;该区发育多期潮流沙脊,反映了本区晚更新世以来经历了多次海进和海退过程。     

Acoustic habitat and shellfish mapping and monitoring in shallow coastal water – Sidescan sonar experiences in The Netherlands

Sidescan sonar has been applied in a number of shallow water environments along the Dutch coast to map and monitor shellfish and seabed habitats. The littoral setting of these surveys may hamper data acquisition flying the towfish in zones of turbulence and waves, but also offers valuable opportunities for understanding, interpreting and validating sidescan sonar images because of the ability to ground-truth during low water periods, enabling easy identification and validation. Acoustical images of some of the mussel banks on the tidal flats of the Wadden Sea, recorded at high tide, show a marked resemblance with optical Google Earth images of the same banks. These sonar images may thus serve as ‘acoustic type signatures’ for the interpretation of sonar patterns recorded in deeper water where ground-truthing is more difficult and more expensive. Similarly, acoustic type signatures of (Japanese) oyster banks were obtained in the estuaries in the southwest of the Netherlands.     

A modeling study of the dynamics of pore water seepage from intertidal marsh sediments

A numerical boundary integral equation model has been used to simulate tidally driven transient variations in pore water seepage from salt marsh sediments into tidal channels and its subsequent recharge by tidal inundation. In general the results show that the maximum seepage discharge occurs at or near the intersection of the creek bank and the channel water surface. Over a tidal cycle typically two-thirds of the total seepage discharge occurs through the creek bank with only about a third discharging from the channel bottom. Of the creek-bank discharge up to a third occurs through the seepage face that develops above the tide line at tidal stages below mean tide. These results indicate that placement of seepage meters only on the channel bottom will not give samples or measures representative of the total seepage. Of the total recharge only about 5% occurs through the upper part of the creek bank with the remainder infiltrating vertically through the marsh platform during early stages of tidal submergence. For the platform recharge about 80% occurs within 3 m of the creek bank. Thus, most of the water that seeps out of marsh sediments is derived from sediments that lie within several meters of the creek bank and accordingly has had a relatively short residence (one to two years) in the marsh. Compared to the distal portion of the marsh this relatively rapid flushing may enhance the productivity of Spartina alterniflora in the creek-bank environment and control the differential generation of radium quartet isotopes.     

Side-scan sonar investigation into temporal variation in sand wave morphology: Helwick sands,Bristol Channel

The morphology and mobility of bedforms within a sand wave field having a water depth of 30 to 40 m have been studied by side-scan sonar surveys at different tidal stages and under various wave climates. Large sand waves with heights of 4 to 7 m retained their orientation throughout the survey period, Small sand waves with heights less than 2 to 3 m changed their height over a tidal cycle and their location (relative to larger sand waves) between surveys. The maximum change appeared to be related to ebb current acceleration. Megaripple wavelengths were reduced under surface wave action.     

The role of tidal vortices in material transport around straits

The strong tidal current (tidal jet) in straits generates tidal vortices with a scale of several kilometers. The role of the vortices in material transport was investigated in the Neko Seto Sea, located in the western part of the Seto Inland Sea of Japan. A clockwise vortex with a diameter of about 0.8 km was observed in Nigata Bay (lying between two straits, the Neko Seto Strait and the Meneko Seto Strait). It was concluded that the clockwise vortex was the tidal vortex which was generated by the tidal jet in the Meneko Seto Strait. The vortex moved into the bay with the tide, but tended to stay on the sand bank in the bay. It was confirmed by current measurement with an ADCP and turbidity measurement that the secondary convergent flow was generated in the bottom layer of the vortex. This secondary flow seemed to contribute to the formation of the sand bank. It was suggested that tidal vortices may play an important role in the sediment transport and formation of topography in and around straits.