Mesoscale sediment transport at southeastern U.S. tidal inlets : Conceptual model applicable to mixed energy settings
Mesoscale sediment transport at southeastern U.S. tidal inlets : Conceptual model applicable to mixed energy settings
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美国东南部潮汐入口处的中尺度沉积物输送：适用于混合能源环境的概念模型
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
P. Work
中科院分区：
文献类型：
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作者：
T. Kana;E. Hayter;P. Work
在中时间尺度（几年到几十年）预测海湾周围的海岸线变化是验证微尺度模型之后的下一个合乎逻辑的步骤。如果中尺度模拟是一个目标，那么一个基本问题是如何及时扩大微尺度模型（模拟数小时至数周的过程），或者宏观尺度地貌模型（定性描述数十年至数百年的变化）是否可以变得更加定量。作者提出了一种方法，开始考虑潮汐入口的形态和沉积物循环周围落潮三角洲。进水口是重点，因为在一些屏障岛设置，如美国东南部海岸，它出现了大多数的海岸侵蚀问题，在中尺度可以追溯到相邻的入口的变化。入口形态和地貌模型，典型的混合能源沿海平原海岸线，进行审查，以说明某些常见的泥沙输运模式。本文提出了一个简化的中时尺度入水口概念模型，由此可对泥沙输移问题进行空间分区。考虑了四个主要入口区域：（A）潮汐产生的落潮流控制沉积物排放的主要落潮流通道，（B）具有宽阔冲流平台的落潮流三角洲，该冲流平台最终在落潮流与波浪和潮汐产生的向岸输送之间保持平衡，（C）落潮三角洲边缘的浅滩绕过区，在此区域，沉积物在波浪作用下从三角洲单向移动到海岸线-产生的运输，和（D）接受浅滩旁路沉积物的入口附近的反弯沙嘴。在D区积累的过量沙受到沿岸平流的影响，流向和远离入口。一部分冲刷邻近的海滩，其余部分冲刷回入口通道（区域A），完成入口输送回路。
Prediction of shoreline change around inlets at meso-time scales (years to decades) is the next logical step following verification of microscale models. If mesoscale simulations are a goal, a basic question is how microscale models (that simulate processes at hours to weeks) can be scaled up in time or whether macroscale geomorphic models (that qualitatively describe changes at decades to centuries) can become more quantitative. The authors propose an approach that begins with consideration of tidal inlet morphology and sediment circulation around ebb-tidal deltas. Inlets are the focus because in some barrier island settings such as the southeast U.S. coast, it appears a majority of coastal erosion problems at meso-time scales can be traced to changes in adjacent inlets. Inlet morphology and geomorphic models, typical of mixed-energy coastal plain shorelines, are reviewed to illustrate certain common sediment transport patterns. A simplified conceptual model of inlets at meso-time scale is proposed from which the problem of sediment transport may be spatially partitioned. Four primary inlet domains are considered: (A) main ebb channel where tidally generated ebb currents control sediment discharge, (B) ebb-tidal delta with a broad swash platform that is ultimately in balance between ebb-directed flows and wave- and tide-generated shoreward transport, (C) shoal bypassing zones at the margins of the ebb-tidal delta where sediment shifts unidirectionally from the delta to the shoreline under wave-generated transport , and (D) recurved spits adjacent to the inlet which receive shoal-bypass sediments. Excess sand accumulating in Domain D becomes subject to longshore advection toward and away from the inlet. A portion nourishes the adjacent beach and the remainder recycles back to the inlet channel (Domain A), completing the inlet transport loop.