Abstract Coastal barrier islands serve as the first line of defense against storm-induced hazards and coastal erosion. Due to sea-level rise and more frequently occurring storms, barrier island restoration and rehabilitation have become more important for coastal protection. The current-state-of-the practice for simulation of barrier island restoration design mostly overlooks consolidation as one of the governing processes. However, low-lying barrier islands, especially those built on loose deltaic or estuarine deposits, may further lose elevation due to consolidation and become more vulnerable to erosion. This study investigates the impacts of consolidation without overwash, overwash without consolidation, and coupled consolidation and overwash in Caminada-Moreau Headland in Louisiana, USA, which is built on loose deltaic deposits. Consolidation and overwash processes were simulated by using Settle3D and XBeach, respectively. The coupled consolidation and overwash simulations predicts twice the elevation loss predicted by the simulations that consider overwash or consolidation only indicating the critical role of consolidation in barrier island morphology. Based on the morphologic changes, feasible restoration strategies are developed and tested through numerical experiments. Our analyses indicate that the simultaneous restoration of the headland and back barrier marsh increases dune volume retention and project design criteria longevity when compared to the coupled simulation without a restored marsh.

中文翻译：

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耦合固结和冲刷过程对低洼陆岬系统的影响

摘要 沿海屏障岛是抵御风暴引起的灾害和海岸侵蚀的第一道防线。由于海平面上升和更频繁发生的风暴，屏障岛的恢复和恢复对海岸保护变得更加重要。障壁岛修复设计模拟的现状大多忽略了作为控制过程之一的固结。然而，低洼的障壁岛，尤其是那些建立在松散的三角洲或河口沉积物上的岛，可能会因固结而进一步降低海拔，并变得更容易受到侵蚀。本研究调查了美国路易斯安那州卡米纳达-莫罗岬角的固结无冲刷、冲刷无固结以及耦合固结和冲刷的影响，该海角建立在松散的三角洲沉积物上。固结和冲刷过程分别使用 Settle3D 和 XBeach 进行模拟。耦合固结和溢流模拟预测的高程损失是考虑溢流或固结的模拟预测的高程损失的两倍，这仅表明固结在障壁岛形态中的关键作用。基于形态变化，通过数值实验开发和测试可行的恢复策略。我们的分析表明，与没有恢复沼泽的耦合模拟相比，同时恢复岬角和后障沼泽会增加沙丘体积保持力和项目设计标准的寿命。耦合固结和溢流模拟预测的高程损失是考虑溢流或固结的模拟预测的高程损失的两倍，这仅表明固结在障壁岛形态中的关键作用。基于形态变化，通过数值实验开发和测试可行的恢复策略。我们的分析表明，与没有恢复沼泽的耦合模拟相比，同时恢复岬角和后障沼泽可增加沙丘体积保持力和项目设计标准的寿命。耦合固结和溢流模拟预测的高程损失是考虑溢流或固结的模拟预测的高程损失的两倍，这仅表明固结在障壁岛形态中的关键作用。基于形态变化，通过数值实验开发和测试可行的恢复策略。我们的分析表明，与没有恢复沼泽的耦合模拟相比，同时恢复岬角和后障沼泽会增加沙丘体积保持力和项目设计标准的寿命。