Bar and berm dynamics during transition from dissipative to reflective beach profile

IF 4.2 2区工程技术 Q1 ENGINEERING, CIVIL

Coastal Engineering Pub Date : 2024-06-15 DOI:10.1016/j.coastaleng.2024.104561

Florian Grossmann , David Hurther , Agustín Sánchez-Arcilla , Enrique M. Padilla , José M. Alsina

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引用次数: 0

Abstract

Bar and berm morphology characterize the seasonal beach evolution, and determine the protection against storm erosion as well as the touristic use of beaches. Thus, they are of particular interest for coastal management and engineering in the nearshore zone. This study used large-scale wave flume experiments to observe the transition from fully dissipative to fully reflective beach profile at a high level of detail. Starting from a post-storm profile generated under energetic waves, a very low energy wave condition caused dissipation of the outer and the inner bar, shoreline recovery, and berm accretion. Measurements revealed feedback between hydrodynamics and beach profile evolution with an onshore shift of the wave breaking location. As a result, the magnitude and cross-shore evolution of wave asymmetry-related bedload net onshore and suspended net offshore transport changed. The relative magnitudes of the two transport components and the way they shifted relative to each other caused the observed beach recovery. Additionally, a link between bar and berm morphology (surf-swash sand exchange) was observed. The shifting breakpoint enabled sustained, wave asymmetry-related onshore transport in the inner surf zone, feeding the berm accretion which occurred through advective swash zone processes including berm overwash.

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从耗散型海滩剖面向反射型海滩剖面过渡期间的横杆和护堤动态

条石和护堤形态是海滩季节性演变的特征，决定了海滩的防风暴侵蚀能力和旅游用途。因此，它们对近岸区域的海岸管理和工程具有特别重要的意义。这项研究利用大型波浪水槽实验，对海滩剖面从完全耗散到完全反射的过渡过程进行了详细观察。从高能量波浪产生的风暴后剖面开始，极低能量的波浪条件引起了外障和内障的消散、海岸线恢复和护堤增生。测量结果表明，流体力学和海滩剖面演变之间存在反馈作用，破浪位置发生了向岸上的移动。因此，与波浪不对称性相关的陆上床面净负荷和近海悬浮物净迁移的规模和跨岸演变发生了变化。这两种迁移成分的相对大小及其相对移动的方式导致了观测到的海滩恢复。此外，还观察到了横杆和护堤形态之间的联系（冲浪-冲沙交换）。断裂点的移动使得内冲浪区与波浪不对称相关的陆上输送得以持续，通过平流冲刷区过程（包括护堤覆盖冲刷）为护堤增生提供了养分。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Coastal Engineering 工程技术-工程：大洋

CiteScore

9.20

自引率

13.60%

发文量

审稿时长

3.5 months

期刊介绍： Coastal Engineering is an international medium for coastal engineers and scientists. Combining practical applications with modern technological and scientific approaches, such as mathematical and numerical modelling, laboratory and field observations and experiments, it publishes fundamental studies as well as case studies on the following aspects of coastal, harbour and offshore engineering: waves, currents and sediment transport; coastal, estuarine and offshore morphology; technical and functional design of coastal and harbour structures; morphological and environmental impact of coastal, harbour and offshore structures.