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1.
基于广利河口水文、地形、地貌及潮汐条件,设计和制作了一个变率为8、水平比尺为400的平面模型。模型地形表面经球体梅花型布置加糙后,再现了天然潮汐及河道径流过程.其主要控制点潮位、流速、流向变化过程与原形实测资料吻合良好。  相似文献   

2.
胶州湾全域的变态物理模型以团岛至薛家岛的狭窄口门处为单边界.依据相似理论,确定胶州湾全域物理模型的水平比尺和垂直比尺分别为1∶700和1∶70.由几何比尺给出模型的流速比尺、糙度比尺、水流时间比尺、流量比尺及潮量比尺.设计胶州湾整体模型的试验水池为宽40 m、长50m、深1 m.试验采用翻板尾门加双向泵以水位控制为主的...  相似文献   

3.
厦门港潮汐水流及浑水悬沙整体物理模型于1989年建成后,已进行了不少有意义的试验研究工作,取得较好效果。本文主要介绍模型的设计思想、相似准则、浑水悬沙相似理论的探讨、模型设计方法以及模型沙的选择等。  相似文献   

4.
研究了日月潮汐改正对精密水准测量的影响,推导出了一种水准测量中可以采用的简单快捷的日月潮汐改正实用模型,并与其他相应模型进行了比较和分析,表明了该模型的实用性和可行性,可应用于海洋测绘中海面地形的确定.  相似文献   

5.
水位波动对临海重力式挡墙基坑稳定性的影响   总被引:1,自引:0,他引:1  
近年来临海(江)建设的地下工程逐渐增多,与常规静水补给条件下的基坑工程相比,受波浪、潮汐等动水作用影响的基坑可能展现出不同的性状,对该类水力条件下基坑响应问题的研究具有重要的工程意义。依托港珠澳大桥珠海连接线拱北隧道海域段基坑工程,采用PLAXIS软件对波浪、潮汐作用下重力式挡墙两侧的水土压力、基坑的稳定性进行了探讨分析。结果表明,对于均质砂质地基上的重力式挡墙,当基坑距防波堤一定距离时,波浪对其稳定性的影响可以忽略不计;潮汐在海床和基坑中的传播有滞后效应,当潮汐为最高潮位时,基坑并非处于最危险状态;潮汐作用下临海重力式挡墙基坑的稳定性可以通过拟静水位法近似分析。  相似文献   

6.
针对调和分析法预报潮汐精度不高的缺陷,论述了神经网络的BP(反向传播)模型用于潮汐预报的可行性和先进性,设计了潮汐预报的BP神经网络模型,论述了模型的算法改进和预报方法过程,用验潮站20多年的潮汐记录,验证了BP模型用于潮汐预报的可行性和精度.  相似文献   

7.
涨潮槽是河口重要的地貌类型,其潮汐动力受地形摩擦、径流及风浪等因素影响而发生不对称现象,直接影响槽内的泥沙动力过程。本文基于实测数据与数值模型计算潮汐不对称偏度,研究长江口南支最大的涨潮槽——新桥水道的潮汐不对称性及其影响因素。结果表明:(1)受余流与各分潮的相互作用控制,新桥水道可分为三个区域,上段为涨潮优势区域,中段为涨落潮转换区域,下段是落潮优势区域。(2)新桥水道欧拉余流表现出明显的分段差异,上段指向陆而在中下段指向海并受到径流影响。斯托克斯余流则均指向陆并向陆增强。(3)新桥水道内中下段潮汐不对称受地形的影响较大,其中扁担沙的北移增强了新桥水道中段的涨潮优势特性,新的新桥通道的形成促进了新桥水道下段的落潮优势特性。  相似文献   

8.
在分析现场实测资料和进行大米草阻力模拟水槽试验的基础上,建立了象山港海域整体潮流泥沙物理模型,取得了模型潮汐水流及泥沙运动与原体的较好相似,分别通过潮汐水流定床和悬沙淤积动床模型试验,对象山县西沪港海洋生态环境修复工程实施前后工程区附近潮汐运动特征、潮流场结构变化和海床淤积情况进行了研究,并分析了工程对军港等重要设施的影响,为项目立项报批及决策提供科学依据,对今后我国大米草综合治理以及类似的海洋生态环境修复工程具有重要的指导意义。  相似文献   

9.
利用潮汐模型NAO.99Jb和FES2014确定了山东邻海的深度基准面模型并对其精度进行了评估,结果表明,NAO.99Jb模型确定的深度基准值L10的中误差为23.28 cm,FES2014模型确定的深度基准值L13的中误差为34.37 cm,长周期分潮的相对误差过大导致加入长周期分潮改正项后深度基准值中误差分别增大了...  相似文献   

10.
华南海岸潮汐汊道P-A关系的分析   总被引:5,自引:0,他引:5  
潮汐汊道是潮汐海岸的重要海岸类型。本文计算华南海岸32个潮汐汊道的平均潮棱体(P)与口门咽喉段平均海面以下的断面积(A),用回归分析法求出标准差最小的P-A最佳回归方程,为乘幂接近于1的乘幂函数形式,与美国沙质海岸、日本基岩港湾海岸研究结果相似。P-A之间除了具有很好的相关性外,还存在着明显的不稳定性。  相似文献   

11.
Five generalized physical models of drfferent distortion ratios were bruit according to DOU Guo-ren‘s similarity theory of total sediment transport modeling for estuarine and coastal regions. Experiments on local scour in front of groins were made under the actions of tidal currents and waves with clear and sediment entraining water. The scour depths under different dynamic actions are compared. The effect of the distortion ratio on the depth of scour hole is discussed. A relationship between scour depths for distorted and undistorted models is given.  相似文献   

12.
象山港避风锚地工程潮流泥沙模型试验研究   总被引:2,自引:1,他引:1       下载免费PDF全文
在分析现场实测资料的基础上,借助象山港整体变态物理模型,通过潮汐水流定床和悬沙淤积试验,对湾内拟建奉化市避风锚地工程实施后,附近海域的潮流场变化和海床淤积情况进行了系统研究。研究结果表明,避风锚地工程对航道、渔港等周边重要设施的影响有限。从而为工程的海洋环评、海域使用论证及工程设计提供了技术支撑,也为半封闭港湾内其它类似涉海工程的可行性论证提供了可借鉴的经验。  相似文献   

13.
A combination of field and numerical modeling methods was used to assess porewater movement in a narrow (20 m) Spartina marsh which was flooded regularly by tidal waters. Soil composition and soil hydraulic properties did not vary across the marsh or with depth. Hydraulic head was monitored on a transect perpendicular to the creekbank. During exposure of the marsh surface, hydraulic gradients were predominantly horizontal; vertical gradients were small or zero. Subsurface flow was directed from the marsh interior toward the creekbank. Approximately 141 of pore water were discharged laterally to the adjacent tidal creek per meter of creekbank over a complete tidal cycle.A numerical hydrological model was modified to simulate subsurface hydraulics in the creekbank vicinity of regularly flooded tidal marshes. The model was parameterized to represent soil conditions, tidal fluctuations and topography at the field site. Observed changes in hydraulic head over complete tidal cycles were accurately predicted by the model. Model simulations identified the vertical infiltration of creek water into the marsh surface at the onset of tidal flooding as the primary source (66%) for the replacement of water drained at the creekbank. Significant replacement (31%) also occurred as discharge from the interior marsh. Horizontal recharge at the creekbank was minimal (3%).A sensitivity analysis was conducted with the model to assess the relative importance of geomorphological factors and soil properties in controlling pore water export at the creekbank of tidal marsh soils. Each parameter was varied systematically over a realistic range for field conditions. Changes in marsh elevation exerted greater control over creekbank discharge than changes in soil hydraulic properties. More rapid turnover of pore water near creekbanks of higher elevation marshes is hypothesized.  相似文献   

14.
滦河三角洲海岸潮汐汊道——潮盆体系的演变   总被引:2,自引:0,他引:2  
近二千年以来,滦河尾闾从西向东迁移,形成了由不同时期的亚三角洲互相叠复而成三角洲体系。丰富的入海泥沙和弱潮环境使该三角洲海岸发育了我国较为完整的潮汐汊道——潮盆体系群。尽管滦河三角洲与密西西比河三角洲有诸多相异之处,但动力泥沙条件的某些相似性使它们的汊道潮盆体系的演变可以进行类比。研究表明,决定潮汐汊道——潮盆体系发育阶段的是它所在的亚三角洲的废弃年龄。从狼窝口到湖林口的各亚三角洲均处于演变的第一阶段。即以受蚀陆岬及其沙咀状堡岛为特色的第一阶段。而大清河口附近则处于以堡岛弧为代表的第二阶段。目前,曹妃甸附近的亚三角洲正在向第三阶段,即堡岛演化为内陆架浅滩的阶段演化。从现代滦河口向曹妃甸,对应于废弃年龄的增加,潮汐汊道分别属于五种类型,即新生波浪型、新生过渡型、潮汐型、老年过渡型及老年波浪型  相似文献   

15.
I feel greatly honored to have recieved the Okada Prize of the Oceanographical Society of Japan this time. I would like to express many thanks to my teachers, and to members of our society, for their kindness provided to me up to the present.Here I have presented some of my studies which are mostly still under way. First I have presented my idea about the study on the near-shore oceanographic processes. Secondly, I have discussed about the significance and the similitude of the hydraulic model experiment, including the model experiment on the tidal mixing. Thirdly, my study on the near-shore oceanographic processes mainly by use of the hydraulic model experiment have been told. They are the effect of boundary geometries on the tidal currents and tidal mixing, the formation processes of the tidal residual circulations, the role of the air-sea boundary processes on the water-mass formation in semi-closed bays and the effect of boundary geometries on the intrusion of salt-wedge.  相似文献   

16.
顾正华  李荣 《海洋工程》2007,25(3):109-114
感潮水闸流量的准确计算对于河网地区水闸引排水效益的分析和水闸综合管理体系的建立具有非常重要的意义。对感潮水闸的水力特性进行了详细分析,认为感潮水闸具有瞬时性和非线性等水力特点,提出采用人工神经网络理论建立其过流量的计算模型。建立了三种计算模式,应用浦东新区东沟水闸资料对不同模式进行了训练、测试和比较,推荐以水闸内外河水位、闸门开启度和上一时刻流量作为神经网络输入的计算模型为最终感潮水闸流量计算模型。研究表明,人工神经网络可以较好地隐含识别感潮水闸的多种出流类型,并具有较强的泛化和容错能力,从而为感潮河网地区水闸流量的计算提供了一种新的解决途径。  相似文献   

17.
Two new types of mechanism for the generation of tidal residual flow are revealed with the use of a hydraulic model experiment. A remarkable anticlockwise tidal residual circulation is formed in a model bay due to the presence of a tidal current, the Coriolis force and a horizontal boundary. A similar circulation is also formed due to the presence of a bottom slope, a horizontal boundary and a tidal current which flows normal to the inclination of the bottom slope. The residual circulation in the Sea of Iyo in the Seto Inland Sea is considered to be due to a combination of the effects of the Coriolis force, a bottom slope, a horizontal boundary and the tidal current. We classified some of the generation mechanisms of tidal residual flow which have been described to date into seven types on the basis of vorticity considerations.  相似文献   

18.
《Coastal Engineering》2005,52(5):409-433
An implicit finite difference formulation of the nonlinear shallow water equations is developed to allow for the treatment of tidal bores and hydraulic jumps. Five different schemes are investigated involving upwind treatment of convective terms, central differences combined with dissipative interface, forward time-centering and various combinations of these techniques. The schemes are analyzed with respect to their effective amplification portraits, and they are tested on periodic bores, uniform bores and steady hydraulic jumps. In this connection the model results are verified against analytical solutions and a numerical solution obtained with a Godunov Riemann solver. Scheme 4, which combines forward time centering and dissipative interface, is found to be superior to the others and it is applicable for Courant numbers within the range 0.25 to 1.5. This scheme is applied to a case study of the tidal bore in Huangzhou Bay and Qiantang River. The model results are shown to be in very good agreement with field data.  相似文献   

19.
因建设需要,拟对钱塘江九溪岸段堤线进行调整。九溪岸段是钱塘江知名的观潮点之一,涌潮是该河段一个重要的自然景观资源。为减小堤线调整对涌潮景观的影响,建立了基于有限元/有限体积法的SCHISM三维涌潮模型,复演了九溪涌潮现象,提出了观潮区的涌潮高度、涌高明显的岸线长度和涌高明显的区域面积等三个综合评价指标,对堤线调整给涌潮带来的影响做出了评价。该研究对其他工程对钱塘江涌潮景观的影响评价具有借鉴意义。  相似文献   

20.
琼州海峡潮流能资源的数值模拟评估   总被引:2,自引:1,他引:1  
近年来,我国能源消耗量不断的增长使我们更加重视可再生能源的开发利用,而我国近海拥有复杂的海岸线和广阔的大陆架,其中许多海域蕴藏着丰富的潮流能资源。潮流能资源评估则是其电站站址选择、发电量预测等工程设计的首要工作。结合两个站位的潮流实测数据,本文利用FVCOM海洋环流数值模式较好的模拟了琼州海峡潮波传播状况,分析了该海域潮流能资源水平分布规律和时间变化特征,初步估算了该水道的潮流能的理论蕴藏量,并采用FLUX方法对该水道的技术可开发量进行了评估。结果表明,琼州海峡中心海域功率密度高,两岸资源低;可能最大流速、大潮年平均最大功率密度、小潮年平均功率密度和年平均功率密度等特征值分布基本相似;其丰富区域出现在海峡东口南部海域以及海峡中部海域,其中东口南部海域可能最大流速可达4.6 m/s,表层流大潮年平均最大功率密度为5996 W/m2,小潮平均最大功率密度仅为467 W/m2,年平均功率密度为819 W/m2,代表点超过0.7 m/s的潮流流速年统计时间约为4717 h;海峡潮流能资源理论蕴藏量为189.55MW,利用FLUX、FARM、GC方法得到该水道的潮流能可开发量分别为249GW/yr、20.2GW/yr和263GW/yr。  相似文献   

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