MORPHODYNAMIC VARIABILITY OF SURF ZONES AND BEACHES:
MORPHODYNAMIC VARIABILITY OF SURF ZONES AND BEACHES:
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冲浪区和海滩的形态动力学变化：
DOI：
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发表时间：
1983
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通讯作者：
A. Syntheis
中科院分区：
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作者：
A. Syntheis
赖特公司和肖特，AD，1984.碎浪带和海滩的形态动力学变化：综合。3月，56：93--118.本文综合了1979---1982年期间对海滩和碎波带动力学的研究结果。本文论述了不同的自然海滩状态，与这些状态相关的过程特征，模态海滩状态的环境控制，以及海滩状态和海滩剖面的时间变化。水动力过程和不同机制对沉积物输运和形态变化的相对贡献作为海滩状态的函数而显著不同，这取决于碎波带和海滩是反射的、耗散的还是处于几种中间状态之一。取决于海滩状态，近底流显示的变化，由于相对优势的运动：入射波，次谐波振荡，亚重力振荡，平均沿岸流和离岸流。在反射海滩上，入射波和次谐波边缘波占主导地位。在高耗散冲浪区，入射波的向岸衰减是伴随着向岸增长的亚重力能量;在内冲浪区，电流与亚重力驻波占主导地位。在中间状态与明显的酒吧槽（直或新月形）地形，入射波轨道速度一般占主导地位，但重要的作用也发挥了分谐波和亚重力驻波，沿岸流，和裂口。最强的裂口和相关的馈线电流发生在与中间横向酒吧和裂口地形。对当地环境条件截然不同的不同海滩进行长期连续调查，提供了数据集，可用于对海滩流动性、变化方向和对环境条件的反应进行经验统计评估。持续的高波能与丰富和/或细粒沉积物相结合的条件导致保持高度耗散状态，表现出非常低的流动性。相对较低的活动性也与作用于粗粒海滩沉积物的持续低陡度波浪有关。在这种情况下，模态海滩状态是反射的。最大程度的流动性与中等但高度多变的波浪条件、中等粒度的沉积物和中等或少量的沉积物供应有关。在这样的条件下，海滩和碎波带倾向于在中间状态之间交替，并表现出发育良好的沙坝槽和韵律地形。弗吉尼亚海洋科学研究所的第1135号贡献是一个很好的关联。0025-3227/84/$03.00 © 1984 Elsevier Science Publishers B.V.
Wright, L.D. and Short, A.D., 1984. Morphodynamic variability of surf zones and beaches: A synthesis. Mar. Geol., 56: 93--118. A synthesis of some results obtained over the period 1979---1982 from a study of beach and surf zone dynamics is presented. The paper deals with the different natural beach states, the process signatures associated with these states, environmental controls on modal beach state, and the temporal variability of beach state and beach profiles. Hydrodynamic processes and the relative contributions of different mechanisms to sediment transport and morphologic change differ dramatically as functions of beach state, that is depending on whether the surf zone and beach are reflective, dissipative or in one of several intermediate states. Depending on beach state, near bottom currents show variations in the relative dominance of motions due to: incident waves, subharmonic oscillations, infragravity oscillations, and mean longshore and rip currents. On reflective beaches, incident waves and subharmonic edge waves are dominant. In highly dissipative surf zones, shoreward decay of incident waves is accompanied by shoreward growth of infragravity energy; in the inner surf zone, currents associated with infragravity standing waves dominate. On intermediate states with pronounced bar-trough (straight or crescentic) topographies, incident wave orbital velocities are generally dominant but significant roles are also played by subharmonic and infragravity standing waves, longshore currents, and rips. The strongest rips and associated feeder currents occur in association with intermediate transverse bar and rip topographies. Long-term consecutive surveys of different beaches with contrasting local environmental conditions provide the data sets for empirical--statistical assessment of beach mobility, direction of change and response to environmental conditions. Conditions of persistently high wave energy combined with abundant and/or fine grained sediment results in maintaining highly dissipative states which exhibit very low mobility. Relatively low mobili ty is also associated with persistently low-steepness waves acting on coarsegrained beach sediments. In such cases, the modal beach state is reflective. The greatest degree of mobility is associated with intermediate but highly changeable wave conditions, medium grained sediment and a modest or meager sediment supply. Under such conditions, the beach and surf zone tend to alternate among the intermediate states and to exhibit well-developed bar trough and rhythmic topographies. A good association is *Contribution No. 1135 from the Virginia Institute of Marine Science. 0025-3227/84/$03.00 © 1984 Elsevier Science Publishers B.V.