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对粤东后江岬间海岸１９９２年和１９９２年７条重复地形剖面分析结果表明,当前各剖面年净冲淤变化很小,剖面分别与Ｂｏｄｇｅ和Ｌｅｅ平衡剖面模式符合良好,拟合的平衡剖面闭合水深反映了在海区波候条件作用下泥沙运动的临界水深。 相似文献
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海滩平衡剖面形态研究进展 总被引：4，自引：0，他引：4
海滩剖面形态是近岸过程与海岸工程环境的一个重要研究内容，对其研究具有重要的理论意义和应用价值。在Brunn-Dean剖面模式的基础上，研究人员提出了许多新的海滩剖面形态模式。作者对近年来提出的各种平衡剖面模式进行了总结，认为加强泥沙动力学研究是解决模式与实际剖面形态偏离的关键。最后作者指出了研究我国岬湾间海滩剖面具有的重要意义。 相似文献
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淤泥质岸滩侵蚀堆积动力机制及剖面模式──以连云港地区淤泥质海岸为例Ⅱ 总被引：5，自引：0，他引：5
本部分则从淤泥质岸滩沉积物的水动力学特征出发，论述了不同状态的泥沙的不同运动规律，给出了两种不同岸段的近岸含沙量和岸滩冲淤率的横向分布的定量表达，并在此基础上建立了侵蚀和堆积岸滩剖面的演变模式，并与实际观测资料进行验证，最后还对岸滩冲淤转化的条件进行了探讨。 相似文献
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利玛原甲藻腹泻性毒素的生物学测定 总被引：5，自引：0，他引：5
１９９４年和１９９５年分季度从海南省三亚海区采集附生于褐藻上的利玛甲藻Ｐｒｏｒｏｃｅｎｔｒｕｍ ｌｉｍａ（Ｅｈｒｅｎｂｅｒｇ）Ｄｏｄｇｅ，经丙酮提取。提取液用ｐＨ＝３的水除去麻痹性贝毒（ＰＳＰ），取残留液注入小白鼠（ＢａＢ／Ｃ纯系），有腹泻性贝毒（ＤＳＰ）中毒的症状出现。初步确定此种藻中提取的毒素为ＤＳＰ。 相似文献
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海滩位于海陆之间的动力敏感地带 ,海滩剖面是近岸过程的一个重要概念。海滩剖面形态受波浪、泥沙、沿岸流、地质等诸多因素的影响 ,使得海滩剖面时空变化极为复杂 ,对其研究具有重要的理论意义。另一方面 ,海滩作为海岸带资源的重要组成部分 ,与人们的生产关系极为密切 ,特别是在高能量的波浪或风暴作用下 ,海滩的巨大变化将对海岸生产设施和海岸工程造成极大的破坏 ,生产和管理部门对此也给予了高度的重视 ,因而这种研究也具有现实运用价值。1 不同能量状况的海滩剖面基本形态根据海滩所受的能量状况的不同 ,研究者常把海滩剖面分为涌浪… 相似文献
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未来海平面上升对厦门海滩侵蚀的测算 总被引：2，自引：2，他引：0
本文通过波浪计算和理论海滩剖面方程的拟合,以Ｂｒｕｕｎ模式为基础,根据Ｅｖｅｒｔｓ剖面积分方法,测算了厦门厦门大学海滨浴场、鼓浪屿港 仔后海滨浴场沙滩未来１００ａ海平面上升引起的海滩后退量值。与此同时,计算了Ｂｒｕｕｎ模式的结果。计算结果表明,两处海滨浴 滩的后退值分别为１４．８１和１３．９５ｍ与Ｂｒｕｕｎ模式的结果相当接近。 相似文献
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淤泥质海岸冲淤变化大，岸滩剖面形态多样。本文首先根据多时相遥感水边线之间的潮差关系自动判断岸滩剖面形态，进而分别采用不同的函数进行剖面拟合，构建了一种剖面形态自适应的海岸线遥感推算新方法，并在江苏中部淤泥质海岸进行了实证应用。研究表明:下凹形侵蚀岸段、斜坡形平缓岸段和上凸形淤长岸段分别采用三指数衰减函数、线性函数和二阶多项式函数具有良好的剖面拟合效果，利用3条水边线数据拟合所得剖面平均坡度绝对误差分别为0.20‰、–0.17‰和0.13‰，小于剖面实测平均坡度一个数量级。利用5条水边线数据拟合进行海岸线推算时，侵蚀岸段、平缓岸段的海岸线平面位置误差分别为6.5 m和–91.96 m，与平均坡度法相比，误差减小约82.4%。进一步考虑岸滩季节性变化时，使用冬季的水边线数据推算海岸线，对侵蚀岸段和淤长岸段影响不大，但对斜坡形平缓岸段，误差减小约63.65%，因此使用冬季的水边线数据比不区分季节具有更高的海岸线推算精度。 相似文献
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我所研制成功了具有当今国际先进水平的脉冲压缩式浅地层剖面仪（ＰＣＳＢＰ），又称Ｃｈｒｉｐ浅地层剖面仪。又称Ｃｈｉｒｐ浅地层剖面仪。它能同时提高地层穿透深度和地层分辨率，其定量化测量特性特别适合于定量研究海底介质的各种特性。本文介绍该仪器的工作原理、结构、性能、特点和使用结果。 相似文献
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Ａｍｏｄｅｌｏｆｐｒｏｆｉｌｅｅｖｏｌｕｔｉｏｎｏｎｗａｖｅ－ｄｏｍｉｎａｔｅｄｍｕｄｃｏａｓｔＺｈａｎｇＹｏｎｇ，ＹｕＺｈｉｙｉｎｇａｎｄＪｉｎＬｉｕ（ＲｅｃｅｉｖｅｄＪｕｌｙ２３，１９９６；ａｃｃｅｐｔｅｄＯｃｔｏｂｅｒ．．８，１９９６）Ａｂｓｔ... 相似文献
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通过物理模型实验研究了海岸沙坝剖面和滩肩剖面的形成和演化过程,给出了稳定的沙坝剖面和滩肩剖面的几何特征。实验中考虑了两种初始坡度(1∶20和1∶10)和不同波高的规则波和不规则波,讨论了不同初始坡度海岸上破碎波空间分布特征。结果表明,沙坝产生后存在向岸和离岸两种运动形态,但最终将停留在稳定位置。稳定的沙坝剖面对应不同初始坡度和波浪存在不同的大沙坝和小沙坝分布。沙坝剖面由长时间小波高波浪序列作用后可转化为稳定滩肩剖面,该剖面不依赖于波浪和初始坡度。实验也给出了平衡剖面与理论曲线的对比以及剖面上泥沙粒径的分布。 相似文献
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The newly developed nearshore circulation model, SHORECIRC, using a hybrid finite-difference finite-volume TVD-type scheme, is coupled with the wave model SWAN in the Nearshore Community Model (NearCoM) system. The new modeling system is named NearCoM-TVD and the purpose of this study is to report the capability and limitation of NearCoM-TVD for several coastal applications. For tidal inlet applications, the model is verified with the semi-analytical solution of Keulegan (1967) for an idealized inlet-bay system. To further evaluate the model performance in predicting nearshore circulation under intense wave–current interaction over complex bathymetry, modeled circulation patterns are validated with measured data during RCEX field experiment (MacMahan et al., 2010). For sediment transport applications, two sediment transport models are applied to predict three sandbar migration events at Duck, NC, during August to October 1994 (Gallagher et al., 1998). The model of Kobayashi et al. (2008) incorporates wave-induced onshore sediment transport rate as a function of the standard deviation of wave-induced horizontal velocities. The modeled beach profile evolution for two offshore events and one onshore event agrees well with the measured data. The second model investigated here combines two published sediment transport models, namely, the total load model driven by currents under the effect of wave stirring (Soulsby, 1997) and the wave-driven sediment transport model due to wave asymmetry/skewness (van Rijn et al., 2011). The model study with limited field data suggests that the parameterization of wave stirring is appropriate during energetic wave conditions. However, during low energy wave conditions, the effect of wave stirring needs to be re-calibrated. 相似文献
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The accuracy of predicting wave transformation in the nearshore is very important to wave hydrodynamics, sediment transport and design of coastal structures. An efficient numerical model based on the time-dependent mild-slope equation is presented in this paper for the estimation of wave deformation across the surf zone. This model incorporates an approximate nonlinear shoaling formula and an energy dissipation factor due to wave breaking to improve the accuracy of the calculation of wave height deformation prior to wave breaking and also in the surf zone. The model also computes the location of first wave breaking, wave recovery and second wave breaking, if physical condition permits. Good agreement is found upon comparison with experimental data over several one-dimensional beach profiles, including uniform slope, bar and step profiles. 相似文献
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海滩响应波浪动力作用的变化是海岸带陆海相互作用研究的重要内容.利用奇异谱分解方法对南湾海滩连续实测剖面的体积变化值与南湾逐日波高变化值的相关关系进行了探讨,以诊断分析波浪在海滩变化过程中的内在作用机制,结果表明:(1)海滩体积的时空变化与波浪作用力有明显的相关关系;(2)海滩响应波浪动力作用变化最明显的地方是在中间岸段,在直线岸段次之,在遮蔽岸段最弱;(3)对海滩变化有较强作用的波浪场分别位于近岸及其与上下岬角连线的邻近区域. 相似文献
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If wave energy is to become a fully-fledged renewable, its environmental impacts must be fully understood. The objective of the present work is to examine the impact of a wave farm on the beach profile through a case study. The methodology is based on two coupled numerical models: a nearshore wave propagation model and a morphodynamic model, which are run in two scenarios, both with and without the wave farm. Wave data from a nearby coastal buoy are used to prescribe the boundary conditions. A positive effect on the wave climate, the cross-shore sediment transport and, consequently, the evolution of the beach profile itself due to the presence of the wave farm was found. The wave farm leads to a reduction in the erosion of the beach face. This work constitutes the first stage of the investigation of the effectiveness of a wave farm as a coastal defence measure, and the accuracy of the quantification of the erosion reduction will be enhanced in future research. In any case, the overarching picture that emerges is that wave farms, in addition to providing carbon-free energy, can be used as elements of a coastal defence scheme. 相似文献
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Wave overtopping nearshore coastal structures, such as shore-parallel breakwaters, can significantly alter the current circulation and sediment transport patterns around the structures, which in turn affects the formation of tombolos and salients in the nearshore area. This paper describes the implementation of a wave overtopping module into an existing depth-averaged coastal morphological mode: COAST2D and model applications to investigate the effect of wave overtopping on the hydrodynamics and morphodynamics around a group of shore-parallel breakwaters. The hydrodynamic aspects of the model were validated against a series of laboratory conditions. The model was then applied to a study site at Sea Palling, Norfolk, UK, where 9 shore-parallel segmented breakwaters including 4 surface-piercing and 5 low-crested breakwaters are present, for the storm conditions in Nov 2006. The model results were compared with laboratory data and field measurements, showing a good agreement on both hydrodynamics and morphological changes. Further analysis of wave overtopping effect on the nearshore hydrodynamics and morphodynamics reveals that wave overtopping has significant impacts on the nearshore circulation, sediment transport and the resulting morphological changes within such a complex breakwater scheme under the storm and macro-tide conditions. The results indicate the importance of including the wave overtopping in modelling nearshore morphodynamics with the presence of coastal structures. 相似文献
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Hurricane Ike (2008), with its associated storm surge, caused extensive damage across parts of the northwestern Gulf Coast when it made landfall in the late hours of September 12, 2008 along the upper Texas coast at the upper end of Category 2 intensity. An extensive instrumentation effort allowed the collection of both nearshore and inland wave and water level data as Hurricane Ike passed the Louisiana coast and made landfall in Texas. This article presents the results of a validation effort for the STWAVE model and the bottom friction coefficients applied in the model with comparisons to the Hurricane Ike measured wave data. Examination of STWAVE model results as contour plots and time series of wave height and period; wave spectra at selected time steps and scatter plots of simulated versus modeled wave results allow evaluation of the model performance. STWAVE model results indicate good agreement with the measured nearshore wave data for an open water Manning ‘n’ bottom friction coefficient equal to 0.03 s/m0.33. STWAVE model results indicate good agreement with the measured inshore wave data with Manning ‘n’ bottom friction coefficients equal to values derived from land classification data and applied in the ADCIRC model. 相似文献