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岬间海湾平面平衡形态规律的研究是砂质海岸稳定与演变研究的重要内容.简要回顾了岬间海湾平面形态规律的研究进展,着重介绍了研究海湾平衡形态的五个模型.通过评述平衡形态模型的优缺点,指出机理分析和经验拟合相结合应该为以后海湾平面平衡形态规律的研究发展方向,并论述了我国岬间砂质海湾平面平衡形态研究的重要意义. 相似文献
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华南岬间砂质海岸稳定性研究 总被引：2，自引：0，他引：2
岬间海湾平衡平面形态规律在海岸长期侵蚀演变预测方面有着广泛的应用,已成为国外研究砂质海岸演变与稳定的重要课题。首先回顾了三种比较典型的经验岬湾形态方程,然后运用当前确定岬间海湾静态平衡形态最广泛使用的经验关系—抛物线关系,对华南31个岬间海湾的稳定状况进行了预测、分类。同时,采用数字岸线分析系统,计算了1990~2000年前后华南岬湾海滩的岸线进退速率,进一步分析、探讨了华南岬间海湾岸滩的稳定状况。 相似文献
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岬间砂质海岸平衡形态模型及其在华南海岸的应用 总被引：1，自引：0，他引：1
本文介绍了对数螺线、双曲线、抛物线三种岬间海湾平面平衡形态模型，并通过对比分析，表明抛物线为三种模型中较为理想的模型．根据抛物线模型的基本原理，本文提供了模型的可行性操作，并就抛物线模型对华南岬间海湾的应用展开了讨论． 相似文献
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海南万宁岬湾海岸海滩稳定性研究 总被引：1，自引：0，他引：1
岬湾海岸海滩的稳定性及其演变是砂质海岸研究的重要内容。基于多期遥感影像、海滩沉积物粒度分布,并采用岬湾海滩平衡形态模型(MEPBAY),分析探讨了海南岛东部万宁4个典型岬湾海岸海滩的稳定性及其模型的应用。研究表明,除东澳湾凸角处于不稳定状态,其余海岸处于静态或准静态平衡状态;岬湾海滩沉积物粒度在遮蔽段和开敞段有明显的差异,相邻海滩之间没有明显的泥沙交换,每个岬湾海滩都是相对独立的地貌单元;模型中上岬角控制点选取应考虑岛礁及水下礁坪;抛物线模型可以拓展应用于有离岸岛情况下的海湾。研究成果可为岬湾海滩的稳定性评估和管理提供科学依据。 相似文献
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研究海湾平衡剖面对理解海湾地貌演变具有重要意义。本文给出了收缩型、扩张型和矩形3种典型海湾平面形态对平衡剖面的影响。建立了海湾长度远小于潮汐波长的短尺度海湾的平衡剖面和对应的时均悬沙浓度的解析解。采用水深平均的水动力方程、泥沙输移方程和地形演变方程的耦合模型对以上3种类型海湾的平衡剖面进行了数值模拟，得到了这3种类型海湾的水面、流速、时均悬沙浓度和平衡剖面的计算结果，并利用水面数值结果确定了海湾水面解析解所含的一个待定常数。研究结果给出了3种不同海湾平面形态所对应的平衡剖面形态:矩形海湾对应斜坡型；收缩型海湾对应下凹型；扩张型海湾对应上凸型。所得海湾平衡剖面和时均悬沙浓度的解析解与数值解一致。 相似文献
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莱州湾东岸沿岸输沙率及冲淤演化动态分析 总被引：1，自引：0，他引：1
采用美国<海岸防护手册>的CERC公式对莱州湾东岸的沿岸输沙率进行计算;同时根据莱州湾东岸自身特征,采用岬间海湾平面平衡形态经验模型-抛物线模型对莱州湾东岸的平衡状态进行预测,结合两者分析得出莱州湾东岸的冲淤演化动态:屺姆岛南侧西端略有冲刷;龙口湾顶基本无泥沙进出;招远岸段遭受严重的侵蚀;石虎咀处于淤积状态.针对侵蚀岸段提出了防止海岸蚀退的对策. 相似文献
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岬间海湾岸线平衡形态神经网络模型 总被引：1，自引：0，他引：1
讨论了目前海湾岸线平衡形态经验模型存在的不足之处。从沿岸输沙公式入手,阐述了平衡岸线的机理模式,重新定义了平衡海湾的“下岬角”,给出了模型参数与主波向的具体计算方法,并以华南典型海湾为学习样本,建立了岸线平衡形态的神经网络模型。通过模拟海湾与实际稳定海湾——乌场湾间的对比分析,表明所建神经网络模型是较抛物模型更为理想的平衡岸线模型。 相似文献
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静态平衡岬湾海岸理论及其在黄、渤海海岸的应用 总被引：6，自引：0，他引：6
岬湾海岸是一种稳定的海岸存在形式,在天然海岸中岬湾地貌占51%。岬湾海岸研究是研究砂质海岸稳定性及演变的重要内容。岬湾海岸理论在海岸稳定性、海岸工程预测以及海岸综合治理方面有其重要的工程价值。文中详细讨论了岬湾理论中最具工程意义的抛物线型岬湾海岸线及基于静态平衡岬湾海岸理论开发的可视化应用软件MEPBay在海岸工程中的应用,并验证了该理论对黄、渤海海岸的适用性。MEPBay软件不仅有助于理解海岸形态过程,也是海岸工程师在岸线保护及海岸管理实践中的有力辅助工具。 相似文献
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Headland-bay beach equilibrium planform has been a crucial problem abroad to long-term sandy beach evolution and stabilization,extensively applied to forecast long-term coastal erosion evolvement and the influences of coastal engineering as well as long-term coastal management and protection.However,little concern focuses on this in China.The parabolic relationship is the most widely used empirical relationship for determining the static equilibrium shape of headland-bay beaches.This paper utilizes the relation to predict and classify 31 headland-bay beaches and concludes that these bays cannot achieve the ultimate static equilibrium planform in South China.The empirical bay equation can morphologically estimate beach stabilization state,but it is just a referential predictable means and is difficult to evaluate headland-bay shoreline movements in years and decades.By using Digital Shoreline Analysis System suggested by USGS,the rates of shoreline recession and accretion of these different headland-bay beaches are quantitatively calculated from 1990 to 2000.The conclusions of this paper include that (a) most of these 31 bays maintain relatively stable and the rates of erosion and accretion are relatively large with the impact of man-made constructions on estuarine within these bays from 1990 to 2000;(b) two bays,Haimen Bay and Hailingshan Bay,originally in the quasi-static equilibrium planform determined by the parabolic bay shape equation,have been unstable by the influence of coastal engineering;and (c) these 31 bays have different recession and accretion characters occurring in some bays and some segments.On the one hand,some bays totally exhibit accretion,but some bays show erosion on the whole.Shanwei Bay,Houmen Bay,Pinghai Bay and Yazhou Bay have the similar planforms,characterized by less accretion on the sheltering segment and bigger accretion on the transitional and tangential segments.On the other hand,different segments of some bays have two dissimilar evolvement characters.Dacheng Bay,Shenquan Bay,Hudong Bay,Wukan Bay,Fengjia Bay,Wuchang Bay,Lingshui Bay and Tufu Bay produce accretion on the tangential segment,erosion on the transitional segment and accretion on the sheltering segment.However,Guang’ao Bay,Haimen Bay,Jinghai Bay,Sanya Bay(a),Dajiao Bay,Hailingshan Bay,Hebei Bay,Fuhu Bay,Shuidong Bay,Wangcun Bay and Bomao Bay generate erosion on the tangential part,accretion on the transitional part and accretion on the sheltering part.It seems to imply some relations between headland-bay beach evolvement and controls on headland-bay beaches,which may possibly to classify headland-bay beach types and should be further studied. 相似文献
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This paper is devoted to the analysis of the hydrodynamic equilibrium of a headland or semi-elliptic shaped beach. It is shown that the state of equilibrium depends not only on the in- and outgoing sediment but also on the accommodation of the sediment within the embayment. The shape and relative depth of shoals, or settling zones, also directly affect the wave and current patterns inside the bay, within which the resultant breaker line almost stops wave-induced currents at some locations, whereas the magnitude of current increases at other locations. Several numerical tests are analytically conducted in a semi-elliptic beach with two symmetrical shoals of varying relative depth where circulatory current systems are detected and analyzed. Numerical modelling for wave climate and wave-induced current estimation is also presented in order to corroborate results and provide a tool for complicated and/or physical domains. The results lead to a redefinition of the concept of equilibrium for headland-bay beaches taking into account not only the net sediment transport but also the role of the formation and disappearance of settling zones, as well as sediment interchanges between the beach and shoals. 相似文献
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受人为工程的影响,相对稳定的岬湾海岸地貌常经历显著的动态调整。本文以粤东靖海湾典型岬湾海岸为例,运用Mc Laren模型、波浪动力场数值模拟、等深线对比、冲淤计算等多种方法,从海岸地貌动力学角度,对人为岬角工程前后岬湾海岸地貌动力过程和冲淤演变进行综合分析。结果表明:1)海岸地貌动力系统内常存在负反馈机制以维持系统的稳定。岬角工程后上岬角防波堤沿SSW延伸,ESE和E向浪经过防波堤时发生绕射,波能削减,湾顶动力减弱,海滩沉积物从下岬角向湾顶反向运移;2)海滩的蚀积状态在工程前后发生了转换,工程前遮蔽段侵蚀、开敞段堆积;工程后遮蔽段堆积、开敞段侵蚀;3)海湾水下地形对岬角工程的响应敏感,工程后海湾水下地形冲淤剧烈。 相似文献
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Equilibrium headland-bay beach systems have been mathematically described by logarithmic, parabolic and hyperbolic curve functions. The largest system of this type reported to date has a shoreline length of about 62 km. In the present study, an apparent headland-bay system is presented which has a shoreline length of about 500 km. It was discovered on satellite images, and is located between Cabo de Santa Maria in Portugal and the coastal city of Rabat in Morocco. It appears to be controlled by long-period North Atlantic swells diffracting around Cabo São Vicente at the south-western tip of Portugal, in combination with SW–SE wind wave climates impinging on the northern shoreline of Cádiz Bay. The coast shows two marked departures from the equilibrium shoreline along its central section north and south of the Strait of Gibraltar, which are easily explained. Thus, the promontories to the north of the strait still exist because there has not been sufficient time to erode these back to the equilibrium shoreline since postglacial sea-level recovery. The coastal indentation to the south is explained by an insufficient sediment supply from terrestrial sources to facilitate the required beach accretion. Perfectly adjusted planimetric headland-bay shoreline shapes represent situations where wave orthogonals approach the coast at right angles everywhere, i.e. there is no longer any alongshore sediment transport. Equilibrium shorelines form independently of the grain size of the beach sediment, whereas morphodynamic beach states are indirectly affected by the shoreline shapes because the latter are modulated by wave period and breaker height which also control the morphodynamic response of the beach in combination with the local grain size. 相似文献
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对海岸侵蚀特征及防治措施效果的分析表明,人工养滩方法是最为环保、长效、经济的海岸侵蚀防治方法.在详细介绍静态平衡岬湾和人工养滩的基本原理的基础上,重点阐述了人工岬湾养滩综合法的设计原则和总体思路,并以北戴河西海滩恢复治理工程为例进行了方案设计. 相似文献