Reconstructing Coastal Sediment Budgets From Beach‐ and Foredune‐Ridge Morphology: A Coupled Field and Modeling Approach
Reconstructing Coastal Sediment Budgets From Beach‐ and Foredune‐Ridge Morphology: A Coupled Field and Modeling Approach
复制标题
从海滩和福乐山脊形态重建沿海沉积物预算：耦合场和建模方法
DOI：
10.1029/2018jf004908
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
J. Lorenzo‐Trueba
中科院分区：
文献类型：
--
作者：
Daniel J. Ciarletta;J. Shawler;C. Tenebruso;C. Hein;J. Lorenzo‐Trueba
保存的海滩和前沙丘脊可以作为海岸变化的替代物，反映海平面、波浪能或过去沉积物通量的变化。特别是，在过去的几十年里，通过对这些系统应用放射性碳和光释光测年，从沙丘脊的相对大小推断出随时间变化的滨面沉积物预算。然而，地质年代学的控制需要广泛的实地调查和分析。基于实地的研究也可能忽视沉积物输送到滨面和沙丘前脊的机制之间的关系，缺少对沉积物预算变化敏感性的认识。因此，我们提出了一个简单的地貌模型的海滩/foredune-ridge和沼泽形态，量化的幅度变化，跨海岸沉积物预算，采用现场测量的山脊体积，山脊间距，海拔和海岸线的扩展。模型行为受到沉积物通量分配到滨面和前沙丘脊的限制，可用于再现自然界中观察到的几种跨海岸模式。这些包括规则间隔的山脊（“洗衣板”），大型奇异山脊和山脊发育不良的宽洼地。我们评估了我们的模型对保存完好的山脊和洼地系统在两个地点沿着弗吉尼亚州东部海岸（美国）：钓鱼点，历史记录提供了详细的历史海岸线侵蚀和山脊的增长，和帕拉莫尔岛，一个相对更复杂的形态发展在一个不受约束的时期的史前增长。我们的研究结果表明，这个新的模型可以用来推断整个地球仪的现场在沉积物输送的变化的敏感性。
Preserved beach and foredune ridges may serve as proxies for coastal change, reflecting alterations in sea level, wave energy, or past sediment fluxes. In particular, time‐varying shoreface sediment budgets have been inferred from the relative size of foredune ridges through application of radiocarbon and optically stimulated luminescence dating to these systems over the last decades. However, geochronological control requires extensive field investigation and analysis. Purely field‐based studies might also overlook relationships between the mechanics of sediment delivery to the shoreface and foredune ridges, missing insights about sensitivity to changes in sediment budget. We therefore propose a simple geomorphic model of beach/foredune‐ridge and swale morphology to quantify the magnitude of changes in cross‐shore sediment budget, employing field measurements of ridge volume, ridge spacing, elevation, and shoreline progradation. Model behaviors are constrained by the partitioning of sediment fluxes to the shoreface and foredune ridge and can be used to reproduce several cross‐shore patterns observed in nature. These include regularly spaced ridges (“washboards”), large singular ridges, and wide swales with poorly developed ridges. We evaluate our model against well‐preserved ridge and swale systems at two sites along the Virginia Eastern Shore (USA): Fishing Point, for which historical records provide a detailed history of shoreline progradation and ridge growth, and Parramore Island, for which a relatively more complex morphology developed over a poorly constrained period of prehistoric growth. Our results suggest this new model could be used to infer the sensitivity of field sites across the globe to variations in sediment delivery.
影响因子：
5.8
作者：
Deaton, Charles D.;Hein, Christopher J.;Kirwan, Matthew L.
通讯作者：
Kirwan, Matthew L.
影响因子：
3.9
作者：
French, Jon;Payo, Andres;Cowell, Peter
通讯作者：
Cowell, Peter