Abstract Ebb-tidal deltas filter incoming wave energy and mitigate erosion of basins and coasts by temporarily providing sediment. In many systems, these coastal safety functions are under threat from human activities. Here we use Delft3D/SWAN to assess the effects of relative sea-level rise and changes in basin area on the long-term dynamics of ebb-tidal deltas. The results show that the time scales of the cyclic channel-shoal dynamics of ebb-tidal deltas are affected. An instantaneous decrease in basin area slows down the cyclic behavior during the initial adjustment period. The duration of the adjustment period increases with larger basin area reduction. After the adjustment, smaller basins have shorter time scales of cyclic channels-shoal dynamics. This is linked to a decrease in tidal prism and ebb-tidal delta volume. Moreover, we find that the effects of relative sea-level rise depend on the rate of rising water levels. For relatively low rates, the period of the cycles eventually shortens, whereas higher rates can cause longer periods. The volume of ebb-tidal deltas appears to be unaffected by relative sea-level rise; but because the average water depth increases, more energetic waves reach the basin. By showing how ebb-tidal deltas adjust to relative sea-level rise and basin area reduction and by unraveling the underlying mechanisms, this study contributes to our understanding of the long-term evolution of tidal inlets.

中文翻译：

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海平面上升和流域面积减少对潮汐入口系统循环行为的影响

摘要 潮汐三角洲通过暂时提供沉积物来过滤传入的波浪能量并减轻盆地和海岸的侵蚀。在许多系统中，这些沿海安全功能受到人类活动的威胁。在这里，我们使用 Delft3D/SWAN 来评估相对海平面上升和流域面积变化对潮汐三角洲长期动态的影响。结果表明，退潮三角洲循环河滩动力学的时间尺度受到影响。盆地面积的瞬时减少减缓了初始调整期间的循环行为。调整期的持续时间随着流域面积减少的增加而增加。调整后，较小的盆地具有更短的循环河滩动力学时间尺度。这与潮汐棱柱和潮汐三角洲体积的减少有关。而且，我们发现相对海平面上升的影响取决于水位上升的速度。对于相对较低的利率，周期的周期最终会缩短，而较高的利率可能会导致更长的周期。潮汐三角洲的体积似乎不受相对海平面上升的影响；但由于平均水深增加，更多的能量波到达盆地。通过展示退潮三角洲如何适应相对海平面上升和盆地面积减少，并通过揭示潜在机制，这项研究有助于我们理解潮汐入口的长期演变。潮汐三角洲的体积似乎不受相对海平面上升的影响；但由于平均水深增加，更多的能量波到达盆地。通过展示退潮三角洲如何适应相对海平面上升和盆地面积减少，并通过揭示潜在机制，这项研究有助于我们理解潮汐入口的长期演变。潮汐三角洲的体积似乎不受相对海平面上升的影响；但由于平均水深增加，更多的能量波到达盆地。通过展示退潮三角洲如何适应相对海平面上升和盆地面积减少，并通过揭示潜在机制，这项研究有助于我们理解潮汐入口的长期演变。