Impacts of Sea‐Level Rise on Morphodynamics and Riverine Flooding in an Idealized Estuary
Impacts of Sea‐Level Rise on Morphodynamics and Riverine Flooding in an Idealized Estuary
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DOI：
10.1029/2022wr032544
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发表时间：
2022-12
影响因子：
5.4
通讯作者：
Wuming Ni;J. Morgan;A. Horner‐Devine;Nirnimesh Kumar;S. Ahrendt
中科院分区：
文献类型：
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作者：
Wuming Ni;J. Morgan;A. Horner‐Devine;Nirnimesh Kumar;S. Ahrendt
本研究模拟一个理想河口在四种不同SLR情景下的形态动力学演变，探讨SLR对河口洪水的影响。我们发现，河口响应SLR的形态变化，通道容量和相关的变化通道水动力的影响。低和中等SLR的情况下，在整个河口的洪水范围相对于没有SLR的基本情况下增加。令人惊讶的是，更严重的SLR的情况下，减少洪水范围在上游河段。这种变化是由于潮汐能的渗透和侵蚀，更大的SLR，这增加了当地的通道容量。此外，由于SLR，我们归因于水文和形态响应之间的时间响应滞后的本地泥沙输运的周期性模式。增加SLR不会导致各地洪水范围增加的发现强调，洪水缓解措施需要仔细考虑河口地貌动力系统中的非线性响应，例如潮汐侵蚀增加导致的反馈。
This research simulates the morphodynamic evolution of an idealize estuary under four different SLR scenarios of increasing severity to investigate how SLR will influence riverine flooding in estuaries. We find that estuarine response to SLR is influenced by both morphological changes to channel capacity and the associated changes to channel hydrodynamics. Low and moderate SLR scenarios result in an increase in flood extent throughout the estuary relative to the no SLR base case. Surprisingly, more severe SLR scenarios result in decreased flood extent in upstream reaches. This shift is due to penetration of tidal energy and erosion further upstream with greater SLR, which increases channel capacity locally. A periodic pattern of local sediment transport is additionally observed due to SLR, which we attribute to the time response lag between hydrological and morphological response. The finding that increased SLR does not result in increased flood extent everywhere emphasizes that flood mitigation measures need to carefully account for non‐linear responses in the estuarine morphodynamic systems, such as the feedbacks resulting from increased tidal erosion.