盆地潮入口系统的长期海平面上升建模揭示了沉积物沉
Kevin C Hanegan1, Duncan M FitzGerald2, Ioannis Y Georgiou3
1Moffatt and Nichol, 601 Poydras St, Suite 1860, New Orleans, LA, 70130, USA.
Nature communications
|November 6, 2023
概括
海平面上升威胁到沿海盐沼地区. 模型显示,减少的潮间区域改变了沉积物流,影响了沼泽的可持续性和沿海沙子资源.
科学领域:
- 沿海的地形形态.
- 盐沼生态学盐沼生态学
- 海平面上升的影响.
背景情况:
- 全球人口集中在海岸线附近,增加了对海平面上升 (SLR) 的脆弱性.
- 障碍岛屿和后壁盐沼是关键的沿海生态系统,覆盖超过10%的海岸线,面临着显著的SLR风险.
研究的目的:
- 在200年的SLR中,模拟后壁环境的形态和水力动态演变.
- 调查沉积物运输动态和沼泽积累对沿海系统弹性的影响.
主要方法:
- 开发了一个数值模型,模拟后壁的演变,具有可侵蚀的床和可变的粒度.
- 分析不同海平面上升情景下的沉积物运输 (砂,沙子,粘土).
- 包括沼泽的垂直积累率,以评估它们对系统动态的影响.
主要成果:
- 减少的潮间区域导致反循环,扭转粗沉积物运输从净出口到进口.
- 沼泽积累暂时将泥土和沙子的进口限制在40年,然后再开始净出口.
- 持续的粘土出口减少了沼泽上的无机沉积物,威胁到它们的长期生存.
- 模拟的沼泽损失导致潮镜和潮三角洲的沙子积累增加,耗尽沿海沙子资源.
结论:
- 沿海盐沼的可持续性受到海平面上升和沉积物动态变化的威胁.
- 沼泽积累可以暂时缓解,但不能消除SLR对沉积物平衡的负面影响.
- 盐沼的损失对沿海形态和沙子资源的可用性产生级联影响.
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