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1.
杭州湾底质的粒度特征和泥沙来源 总被引：4，自引：0，他引：4
杭州湾底质的分布,与潮流、波浪作用以及泥沙来源有着密切的关系。作为强潮海湾的杭州湾,潮流作用是主要的动力因素。底质的粒径大小与水动力强度相适应。底质的类型以泥质粉砂和粉砂为主。底质的分布具有一定的规律性,从湾口向湾内,颗粒粒径由细到粗,分选则由差到好。杭州湾的泥沙来源,以海域来沙为主,其中主要是长江输出的泥沙,随涨潮流进入杭州湾。 相似文献
2.
福建安海湾表层沉积物粒度特征及其现代沉积过程分析 总被引：1，自引：0，他引：1
通过对福建安海湾表层沉积物的粒度分析和对比,应用系统聚类分析、粒径趋势模型和切应力计算公式,探讨了研究区粒度的分布特征、沉积环境分区、表层沉积物输运趋势及其影响因素.研究结果表明,研究区包括6种表层沉积物类型,以黏土质粉砂和粉砂为主,沉积物大体呈现自海湾两侧潮滩向潮汐通道变粗的分布趋势.表层沉积物粒度的分布特征与水动力条件和物质来源密切相关,湾口附近及湾内深槽内,细颗粒的沉积物被再悬浮带走,粗颗粒的含量增大;在湾内潮滩上,悬浮物质因水动力作用逐渐减弱发生分选沉降,形成向岸变细的横向分异.海湾外泥沙随潮流不断地向海湾东侧岸滩运移,海湾周边陆源来沙由湾顶部往湾口方向下泄,两者是导致表层沉积物出现明显的顺时针方向汇聚趋势的原因之一;表层沉积物的输运趋势、悬浮泥沙的输运、潮滩植被与湾口沙嘴的遮蔽效应共同影响了研究区内浅滩地形的形成和变化.研究区可分为四类沉积环境区,以潮滩和潮汐通道环境为主,不同沉积区内的粒度参数、粒级频率和敏感粒级均有差异,动力条件差异和不同物源的影响程度是现代沉积环境格局的主要影响因素. 相似文献
3.
《China Geology》2019,2(3):325-332
Based on the 39 surface sediment samples collected in the flood season and the dry season in 2012 respectively and the measured hydrological data in October 2012, the sediment grain size characteristics has been analyzed and the response mechanism of surface sediments to estuarine hydrodynamics was revealed by calculating the range of waves and tidal currents. The results show that: (1) The grain size of the surface sediment samples decreased gradually from land to sea in the flood season. The fine sediment was redistributed under marine hydrodynamics in the dry season and the sediments showed coarser tendency ingeneral; (2) tidal current stirring sediment was very obvious in Dagu River estuary area, and wave stirring sediments mainly occurred in the tidal flat area and estuary sand bar area; (3) in the flood season, surface sediment sat the estuary were transported towards south and southeast. In the dry season, surface sediments were transported towards southwest at the north area of Jiaozhou Bay Bridge, and sediments were transported towards northeast area at the south of Jiaozhou Bay Bridge. 相似文献
4.
河海交互作用沉积与平原地貌发育* 总被引：3，自引：15，他引：3
河流是搬运陆源泥沙的主要动力,对相邻的海岸海洋沉积动力有巨大影响。中国河流汇入海洋中的泥沙曾占全球入海泥沙的10 ％ ,现代中国边缘海大陆架在晚更新世时曾是海岸平原,河-海交互作用是形成海岸平原与浅海输积泥沙的主要因素。本文选择5个不同类型的河流展示其不同的泥沙运动与河口沉积的特性以及对相邻陆架之影响,包括: 1)强潮型动力的鸭绿江河口湾,形成从陆向海与从海向陆的双向水流交汇沉积,海岸形成潮流脊体系。 2)季风波浪为主导动力的滦河口,以泥沙的横向运动为主,形成沙坝环绕的双重海岸,沉积粒径自海向陆减小; 沿岸浪流携运泥沙向河口两侧分布,使沙坝具有沙咀状的复合特点。 3)弱潮型、多沙的黄河口,径流于两侧堆积指状沙咀,沙咀下风侧形成粉砂粘土淤泥湾,沿岸流携运泥沙向渤海湾延伸为淤泥舌。 4)径流与沿岸流组合作用的沉积模式,以长江口为代表,泥沙沿岸向南输运为主导,向海岸与向内陆架构成颗粒变细的带状沉积,外陆架出露残留砂。 5)充填河口湾的三角洲,以珠江为代表,河流分汊与会潮点泥沙堆积,悬移质扩散至湾外,被沿岸流携带沿海岸向SW运移,外陆架为残留砂沉积。20世纪80年代以来,上述河流均受到人为活动的改造影响,河流自然过程与河海交互作用效应均发生改变。本文主要以滦河三角洲为例阐述河-海交互作用与平原的地貌特征。 相似文献
5.
Sediment transport and trapping in the Hudson River estuary 总被引：3，自引：0，他引：3
The Hudson River estuary has a pronounced turbidity maximum zone, in which rapid, short-term deposition of sediment occurs during and following the spring freshet. Water-column measurements of currents and suspended sediment were performed during the spring of 1999 to determine the rate and mechanisms of sediment transport and trapping in the estuary. The net convergence of sediment in the lower estuary was approximately 300,000 tons, consistent with an estimate based on sediment cores. The major input of sediment from the watershed occurred during the spring freshet, as expected. Unexpected, however, was that an even larger quantity of sediment was transported landward into the estuary during the 3-mo observation period. The landward movement was largely accomplished by tidal pumping (i.e., the correlation between concentration and velocity at tidal frequencies) during spring tides, when the concentrations were 5 to 10 times higher than during neap tides. The landward flux is not consistent with the long-term sediment budget, which requires a seaward flux at the mouth to account for the excess input from the watershed relative to net accumulation. The anomalous, landward transport in 1999 occurred in part because the freshet was relatively weak, and the freshet occurred during neapetides when sediment resuspension was minimal. An extreme freshet occurred during 1998, which may have provided a repository of sediment just seaward of the mouth that re-entered the estuary in 1999. The amplitude of the spring freshet and its timing with respect to the spring-neap cycle cause large interannual variations in estuarine sediment flux. These variations can result in the remobilization of previously deposited sediment, the mass of which may exceed the annual inputs from the watershed. 相似文献
6.
The distribution of macroinfauna was quantified in subtidal, soft-bottom habitats, extending from the estuarine mouth to the tidal head of the Gamtoos—a small, shallow, temperate estuary situated on the south coast of South Africa. Sampling covered the full salinity gradient from fresh to marine waters, and all sediment types from marine sands to fluvial silts. A total of 35 taxa was recorded, of which 22 occurred throughout the year. Species richness and diversity declined from the seawater-dominated mouth region toward the fresh water section at the tidal head of the estuary. Sediment type generally bore no clear relation to biotic diversity. A marked drop in salinity between winter and summer sample series (Δ 0.2‰ to 24‰) coincided with a reduction of mean macrofaunal density by 70%, a more seaward relocation, and a compression of axial ranges of most taxa. Numerical classification and ordination of faunistically similar regions and of co-occurring species delineated four habitat zones along the longitudinal axis of the estuary which harbour four distinct macrofaunal assemblages: 1) A tidal inlet area with salinities close to seawater; clean, coarse, marine sands, rich in CaCO3 harbour a stenohaline fauna normally found on adjacent, marine sandy beaches. 2) In the lower reaches, where fine, fluvial silts of high organic content prevail, euryhaline polychaetes dominate the macrozoobenthic community; bottom salinities in this zone seldom dropped below 25‰ 3) The middle reaches, characterized by oligohaline- to polyhaline waters, stretch over sandy sediments of intermediate carbonate, silt, and organic fractions; the fauna comprises typical estuarine forms, which occurred throughout most of the estuary except at its seaward and landward limits. 4) The upper reaches encompass the limnetic waters near the tidal head of the estuary with sediments in this zone being composed mostly of coarse, clean sands, low in CaCO3; the macrobenthos in this region is dominated by taxa of freshwater origin, which generally do not penetrate seaward beyond the oligohaline waters, and by exceptionally euryhaline estuarine species. Salinity appears as the main factor in controlling faunal assemblages at both extremes of the estuarine gradient (i.e., tidal inlet and head), whereas sediment type delineates between communities in the mesohaline to polyhaline reaches. Axial (i.e., from tidal inlet to tidal head of the estuary) zonation patterns of macroinfauna broadly matched those of mesozooplankton and fishes, supporting the notion of a general structure underlying species distribution patterns in the Gamtoos estuary. 相似文献
7.
在深圳湾西北部海域进行表层沉积物取样,通过粒度分析获取沉积物粒度参数。结果表明,该海域中北部沉积物以粉砂为主,分选较差;局部有较粗的砂、砾沉积物分布,分选性差。地质统计分析结果显示,粒度参数半方差—距离的相关性与沉积物粒度参数的空间分布有关,剔除空间“异常”值后,可在半方差图中获取粒度参数的变程值,并将其作为粒径趋势模型的特征距离。粒径趋势分析表明,海湾西部海域的沉积物向东北净输运,深圳河口海域的沉积物偏西向输运,从而在海湾北部近岸海域形成一个沉积物汇聚中心,这与水动力观测结果基本吻合。此外,210Pb测年结果也表明,这个沉积物汇聚中心的沉积速率也相应较高,显示出较强的淤积趋势。 相似文献
8.
Joshua Griffiths Richard H. Worden Luke J. Wooldridge James E. P. Utley Robert A. Duller Rhiannon L. Edge 《Sedimentology》2019,66(6):2011-2047
The spatial distribution of clay minerals in sandstones, which may both enhance or degrade reservoir quality, is poorly understood. To address this, clay mineral distribution patterns and host‐sediment properties (grain size, sorting, clay fraction abundance and bioturbation intensity) have, for the first time, been determined and mapped at an unprecedentedly high‐resolution in a modern estuarine setting (Ravenglass Estuary, UK). Results show that the estuary sediment is dominated by illite with subordinate chlorite and kaolinite, although the rivers supply sediment with less illite and significantly more chlorite than found in the estuary. Fluvial‐supplied sediment has been locally diluted by sediment derived from glaciogenic drift deposits on the margins of the estuary. Detailed clay mineral maps and statistical analyses reveal that the estuary has a heterogeneous distribution of illite, chlorite and kaolinite. Chlorite is relatively most abundant on the northern foreshore and backshore and is concentrated in coarse‐grained inner estuary dunes and tidal bars. Illite is relatively most abundant (as well as being most crystalline and most Fe–Mg‐rich) in fine‐grained inner estuary and central basin mud and mixed flats. Kaolinite has the highest abundance in fluvial sediment and is relatively homogenous in tidally‐influenced environments. Clay mineral distribution patterns in the Ravenglass Estuary have been strongly influenced by sediment supply (residence time) and subsequently modified by hydrodynamic processes. There is no relationship between macro‐faunal bioturbation intensity and the abundance of chlorite, illite or kaolinite. Based on this modern‐analogue study, outer estuarine sediments are likely to be heavily quartz cemented in deeply‐buried (burial temperatures exceeding 80 to 100°C) sandstone reservoirs due to a paucity of clay grade material (<0·5%) to form complete grain coats. In contrast, chlorite‐enriched tidal bars and dunes in the inner estuary, with their well‐developed detrital clay coats, are likely to have quartz cement inhibiting authigenic clay coats in deeply‐buried sandstones. 相似文献
9.
JAMES R. STEIDTMANN 《Sedimentology》1982,29(6):877-883
It is well known that sediment sorting according to size, shape and density occurs, but the exact mechanisms involved are poorly understood. To assess the effects of size and density, sand-size spheres of two densities were transported and deposited under controlled flume conditions. Observations on the motion of discrete particles show that grains smaller than bed-roughness grains move continuously and have the same transport velocities regardless of density. For grains near and slightly larger than the roughness, movement is intermittent and, for a given size, heavy particles move more slowly than lights. For grains much larger than bed roughness grains, movement is continuous over the rough surface and light and heavy grains have nearly the same transport velocities. Analyses of bulk sediment deposited from plane-bed transport, show that the size and proportion of heavies decreases and that of lights increases with distance transported. For ripple bed transport, however, the size relations between associated light and heavy grains remains essentially unchanged with transport distance and the proportion of light and heavy grains is extremely variable. These results suggest that size-density sorting in plane-bed transport is a function of the transportabilities identified in the discrete grain studies but that sorting in ripple-bed transport is related to deposition on, and recycling through, the bed forms. Application of these findings to the concept of hydraulic equivalence implies that some indication of bed configuration may be necessary for the concept to be useful. 相似文献
10.
本研究通过对长江口现代潮滩6个柱状样沉积物的粒度精细分析,试图提取研究区潮滩沉积相识别的粒度敏感指标,并通过对长江三角洲南部平原一个全新世钻孔(SL67孔)潮滩沉积物的粒度研究,检验现代沉积粒度敏感指标在全新世钻孔潮滩沉积相识别中的应用。研究显示,长江口现代高潮滩和中潮滩的黏性颗粒(8μm)和粗粉砂(32~63μm)含量差异显著,可以成为区分高潮滩和中潮滩的敏感组分;在开敞型的中、低潮滩之间,砂(63μm)和细粉砂含量(8~32μm)也差异明显。长江口现代潮滩沉积物的粒度频率曲线及众数值也可以有效协助区分高潮滩、中潮滩和低潮滩沉积物。利用上述粒度敏感组分和众数指标检验SL67孔全新世早中期在海平面波动控制下的潮滩演替过程,并揭示了7.5 cal ka BP前后的一次海平面加速上升事件。 相似文献
11.
辽河口海口沉积特征及潮滩动态预测 总被引：6，自引：0，他引：6
本文以翔实的调查资料较详细的叙述了辽河口浅海区的沉积特征,分别总结了潮滩、浅海、潮道及潮沟等单元体的沉积特征,并分析了各单元体的沉积过程,文章重点叙述了潮滩的动态变化,并根据210Pb测定沉积速率资料及河流输沙量观测资料,分别建立预测方程,估算了双台河口东、西两段潮滩的极限淤涨时间及潮滩淤涨高度预测,两种计算方法所获得的结果基本上一致。 相似文献
12.
The Ouémé River estuary is located on the seasonally humid tropical coast of Benin, west Africa. A striking feature of this microtidal estuary is the presence of a large sand barrier bounding a 120 km2 circular central basin, Lake Nokoué, that is being infilled by heterogeneous fluvial deposits supplied by a relatively large catchment (50 000 km2). Borehole cores from the lower estuary show basal Pleistocene lowstand alluvial sediments overlain by Holocene transgressive–highstand lagoonal mud and by transgressive to probably early highstand tidal inlet and flood‐tidal delta sand deposited in association with non‐preserved transgressive sand barriers. The change in estuary‐mouth sedimentation from a transgressive barrier‐inlet system to a regressive highstand barrier reflects regional modifications in marine sand supply and in the cross‐barrier tidal flux associated with barrier‐inlet systems. As barrier formation west of the Ouémé River led to an increasingly rectilinear shoreline, the longshore drift cell matured, ensuring voluminous eastward transport of sand from the Volta Delta in Ghana, the major purveyor of sand, to the Ouémé embayment, 200 km east. Concomitantly, the number of tidal inlets, and the tidal flux associated with a hitherto interlinked lagoonal system on this coast, diminished. Complete sealing of Lake Nokoué has produced a large, permanently closed estuary, where tidal intrusion is assured through the interconnected coastal lagoon via an inlet located 60 km east. Since 1885, tides have entered the estuary directly through an artificial outlet cut across the sand barrier. Although precluding the seaward loss of fluvial sediments, permanent estuary‐mouth closure has especially deprived the highstand estuary of marine sand, a potentially important component in estuarine infill on wave‐dominated coasts. In spite of a significant fluvial sediment supply, estuarine infill has been moderate, because of the size of the central basin. Estuarine closure has resulted in two co‐existing highstand sediment suites, with limited admixture, the marine‐derived, estuary‐mouth barrier and upland‐derived back‐barrier sediments. This situation differs from that of mature barrier estuaries characterized by active fluvial‐marine sediment mixing and facies interfingering. 相似文献
13.
Jianhua GAO Yang YANG Yaping WANG Shaoming PAN Rui ZHANG 《Frontiers of Earth Science》2008,2(3):249-261
High-resolution current velocity and suspended sediment concentration (SSC) data were collected by using an Acoustic Doppler
Current Profiler (ADCP) at two anchor stations and a cross-section in the South Channel of the Changjiang River mouth during
meso and neap tides on Nov. 16, 2003. In addition, tidal cycle (13-hour) observation at two stations was carried out with
traditional methods during the spring tide. Results indicated that resuspension occurred not only at the flood and ebb maximum,
but also in the early phase of ebb in the meso and neap tide. When tidal current transited from high to ebb phase, current
speed accelerated. Subsequently, fine-grained sediment with low critical threshold was resuspended and increased concentration.
The river mouth area remained in siltation in the meso and neap tidal phase during the observation season, with calculated
resuspension flux in the order of magnitude of 10−4–10−7 kg·m−2/s. Suspended sediment transport in the South Channel was dominated by freshwater discharge, but the Storks drift,
vertical circulation and vertical shear effect due to tidal oscillation also played an important role in resuspension and
associated sediment transport. In contrast, resuspension sediment flux in the spring tide was larger than that in meso and
neap tide, especially at the ebb maximum and flood maximum. The present study revealed that intensive resuspension corresponded
well with the larger current velocity during winter. In addition, the ‘tidal pumping’ effect and tidal gravity circulation
were also vital for forming the turbidity maximum in the Changjiang River estuary. 相似文献
14.
Grain‐size distributions and coastal morphodynamics along the southern Maryland and Virginia barrier islands 
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下载免费PDF全文 This study examined grain‐size distributions to address questions regarding geological and oceanographic controls on island morphodynamics along one of the longest undeveloped, mixed‐energy barrier island systems in the world. In particular, statistical analyses (i.e. analysis of variance, Tukey honest significant difference multiple comparison tests, nonparametric statistics and linear regression analysis) of 230 barrier island samples from Ocean City Inlet, Maryland, to the mouth of the Chesapeake Bay and 134 nearshore samples (d ≤ 10 m) identified grain‐size trends related to the morphodynamic characteristics of these systems. In general, the Virginia barrier islands north of Wachapreague Inlet and Assateague Island form a statistically different subset of grain sizes (medium‐grained to coarse‐grained sand) from the islands south of Wachapreague Inlet (fine‐grained sand). These textural trends corroborate the Pleistocene headlands of the Delmarva coastal compartment as the sediment source and indicate that some of the coarse‐grained to medium‐grained sediment bypasses the large sinks in the net southward longshore sediment transport system (i.e. Fishing Point and Chincoteague Inlet). This research also demonstrates that the preferential accumulation of coarse‐grained to medium‐grained sand on the ebb‐tidal delta at Wachapreague Inlet probably controls the erosional morphodynamics of the islands located downdrift (south) of the inlet. These results suggest that an increase in tidal prism, set up by sea‐level rise and/or a shift in wave climate/refraction patterns, may lead to barrier island fragmentation and a runaway transgression of this predominantly natural barrier island system. Consequently, a grain analysis of major coastal compartments, across multiple driving forces, can be used to assess coastal morphodynamics and the potential impact of climate change on coastal systems. 相似文献
15.
为了研究河床粗化破坏与形成过程中推移质的输移特征,基于一套新型的接沙系统,在上游无来沙条件下,进行了3组不同床沙级配的水槽试验,研究了递增梯级流量作用下河床粗化破坏与形成的过程,采集到一套高精度（0.1 g）、高频率（1 Hz）的实时推移质输沙率及分时段输沙级配数据,分析了累积输沙量、输沙率及输沙级配的变化特征。结果表明,粗化过程中累积输沙量随时间基本呈幂函数规律增长,且"粗化破坏再形成"的累积输沙量曲线出现明显转折点;推移质输沙率表现出明显的非恒定性,其粗化形成阶段的耗时要远大于粗化破坏阶段的时间,两者之比范围为3.5~20.5;推移质输沙级配中粗颗粒比例随时间变化趋势与输沙率相似,在输沙率达到峰值附近时,输沙级配与原始床沙级配相同。 相似文献
16.
The relative roles of waves and tidal currents in transporting bottom sediment on the continental shelf off Lands End, southwest England, are evaluated by study of (a) sediment grain size in relation to boundary layer measurements in tidal currents, (b) regional variation in sediment parameters in relation to peak tidal and wave-induced currents, and (c) visual observation of bedforms. (a) The sediments are mainly zoogenic sands. The average hydraulic equivalent median diameter is Mdφ=1.40φ (medium grade sand), and two-thirds of the median grain sizes fall between 0.97φ and 1.83φ. The linear bottom current which will just move this range of sizes is exceeded only slightly by the highest tidal drag velocities ū* measured in the area. Thus, sediment movement by tidal currents alone is restricted to areas of high bed roughness and strong peak tidal flows. In contrast, wave-induced oscillatory currents at 100 m depth (typical of the area) attain sufficient speed to disturb the same particle sizes over 3% of the time. This includes storm periods when much greater velocities occur. (b) The average Mdφ of the sediment decreases southwest and northeast from south of the Lizard. This correlates well with the pattern of maximum tidal current speeds, suggesting that tidal currents control the areal distribution of sediment median grain size. Most sediments are well sorted (mean σi=0.48φ). Sorting improves at shallower depths but does not improve in areas of faster tidal currents, suggesting that wave-induced currents exert the major control on sorting. Silt and clay proportions increase west of the Scilly Isles and are influenced by both wave and tidal currents. (c) Photographs and television pictures show that symmetrical bedforms due to wave action are dominant north and west of the western Channel. Asymmetric bedforms are more common in the western Channel itself, where tidal currents and bed roughness are both high. Results are used to construct a sediment transport model for the study area. Since medium grade well sorted sands occur in depths of over 100 m, many ancient, extensive, well sorted sand sheets may have been deposited at depths greater than previously suspected. 相似文献
17.
18.
Hydrodynamic data and samples of bed sediment were collected from Nara Inlet, a small incised embayment in the Whitsunday Islands, central Great Barrier Reef. Measured tidal currents in the inlet do not exceed 0.2 ms–1 even at spring tides. Swell waves dominate much of the inner shelf of the Great Barrier Reef but are absent from in the inlet due to the presence of a fringing reef at the inlet mouth. On the silty sand floor of the inlet, particle size decreases towards the inlet head. Most of the bed is too coarse to be remobilised by fair‐weather wave and tides, and we predict that bedload sediment transport thresholds are only exceeded in the inlet during cyclones. The observed distribution of bed sediments is consistent with landward dispersal of sediment under storm conditions. Over 20 m of (presumably Holocene) sediments occurs in the inlet and the seismic character of the infill is consistent with the observed textural variation of the modern sediments. We infer that sediment accumulation on the floor of the inlet has been storm dominated throughout much of the Holocene. 相似文献
19.
Dr. Klaus-Werner Tietze 《International Journal of Earth Sciences》1978,67(3):1016-1033
Field research of wave generated bed forms within complex sediment size distributions near the inlet of a tidal lagoon at the northern coast of Brittany has stimulated an experimental study in a laboratory wave tank. Several sediment mixtures, most of them with bimodal grain size distributions, were exposed to different monochromatic shallow water waves. The observations and measurements included the dynamics of the water waves and the generation, shape, and size of oscillatory bed forms. The experiments confirm the known relationship between grain size and ripple size. In addition it is shown that coarse sand, added to a preexisting fine bed material leads to an increasing asymmetry of ripples. There is some suggestion that the variability of ripple heights is reduced by higher contents of coarse sand. Bimodal sediment size distributions obviously do not cause unusual geometry of ripples — at least within the range of the experimental tests. The different sand size modes move together in one phase, forming structures with more or less homogeniously distributed bed material. Differentiation of sediment sorting does of course occur, but this is in the range of the whole test section. Finally the experiments allowed to test the validity of some wave formulas. The own experiments are compared with some results from field and laboratory studies of other authors. 相似文献
20.
黄河三角洲滨海区沉积物的分异特征与规律 总被引：7，自引：0，他引：7
根据2000年79月黄河三角洲滨海区表层沉积物的分析结果,运用F lem ing的三角图式对沉积环境进行划分,并在此基础上结合沉积物结构、地形和水动力条件,探讨了沉积物的分布规律及其作用机制。结果表明:研究区域可划分为废弃三角洲滨海区、现行河口区和莱州湾滨海区三个沉积环境。对于废弃三角洲沉积区,在早期废弃的湾湾沟海区风浪作用为主,沉积物普遍较粗,抗冲能力较强;废弃不久的飞雁滩海区在波流联合作用下,沉积物粒径由岸向海变细,大致在-5-6m水深处存在一明显的界限,该水深以浅砂含量较高;而该水深以深以粉砂和粘土为主,砂含量较低。现行河口区,由于沙嘴前方强潮流带的作用,沉积物粒径由岸向海表现为粗—细—粗的演变趋势。在莱州湾海区,由于潮流场的影响,以广利河河口为界,以北粒径较细,而以南则较粗。 相似文献