Coral reefs are widely recognized for providing a natural breakwater effect that modulates erosion and flooding hazards on low‐lying sedimentary reef islands. Increased water depth across reef platforms due sea‐level rise (SLR) can compromise this breakwater effect and enhance island exposure to these hazards, but reef accretion in response to SLR may positively contribute to island resilience. Morphodynamic studies suggest that reef islands can adjust to SLR by maintaining freeboard (island crest elevation above still water level) through overwash deposition and island accretion, but the impact of different future reef accretion trajectories on the morphological response of islands remains unknown. Here we show, using a process‐based morphodynamic model, that, although reef growth significantly affects wave transformation processes and island morphology, it does not lead to decreased coastal flooding and island inundation. According to the model, reef islands evolve during SLR by attuning their elevation to the maximum wave runup and islands fronted by a growing reef platform attain lower elevations than those without reef growth, but have similar overwash regimes. The mean overwash discharge Q_over across the island crest plays a key role in the ability of islands to keep up with SLR and maintain freeboard, with a Q_over value of O (10 l m⁻¹ s⁻¹) separating island construction from destruction. Islands, therefore, can grow vertically to keep up with SLR via flooding and overwash if specific forcing and sediment supply conditions are met, offering hope for uninhabited and sparely populated islands. However, this physical island response will negatively impact infrastructure and assets on developed islands.

中文翻译：

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未来珊瑚礁生长对珊瑚礁岛屿对海平面上升的形态反应的作用

珊瑚礁因提供天然的防波堤作用而受到调节，因此可以调节低洼沉积礁岛上的侵蚀和洪水危害。由于海平面上升（SLR）而使礁石平台上的水深增加，可能会损害防波堤的影响并增加岛屿对这些危害的暴露，但是响应SLR的礁石增生可能会为岛屿的复原力做出积极贡献。形态动力学研究表明，礁石岛可以通过过度冲洗沉积和海岛增生来保持干舷（高于静止水位的岛顶海拔），从而适应单反，但未来不同礁石增生轨迹对岛屿形态反应的影响仍然未知。在这里，我们展示了使用基于过程的形态动力学模型，尽管珊瑚礁的生长会显着影响海浪的转变过程和岛屿的形态，但并不会减少沿海的洪水和岛屿的淹没。根据该模型，礁石岛在单反时会通过将其海拔高度调至最大波浪上升而演变，而礁石平台正对着的礁石的海拔比没有礁石生长的礁石要低，但具有类似的过度冲洗状态。平均冲洗量Q_在全岛嵴起着岛屿的单反，以保持和维护的干舷，有能力的关键作用Q_在价值Ø（10流明^-1小号^-1从毁灭中分离岛建设）。因此，如果满足特定的强迫和沉积物供应条件，岛屿可以通过洪水和过度冲洗垂直生长以跟上SLR的步伐，这为无人居住和人口稀少的岛屿提供了希望。但是，这种实际的岛屿反应将对发达岛屿的基础设施和资产产生负面影响。