Barrier island bistability induced by biophysical interactions
Barrier island bistability induced by biophysical interactions
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DOI：
10.1038/nclimate2474
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发表时间：
2015-02
影响因子：
30.7
通讯作者：
O. D. Vinent;L. Moore
中科院分区：
文献类型：
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作者：
O. D. Vinent;L. Moore
堰塞岛约占世界海岸线的10%，维持着丰富的生态系统，拥有宝贵的基础设施，并保护大陆海岸免受风暴的侵袭。未来气候变化导致的主要飓风强度和频率的增加以及海平面上升的加速，将对屏障岛屿产生重大影响，导致沿海灾害和洪水增加，但我们对岛屿对外部驱动因素的反应的了解仍然有限。在这里，我们发现岛屿的反应本质上是双稳的，并受以前未知的动力控制：风暴侵蚀、海平面上升以及使沙丘恢复和驱动沙丘恢复的风沙和生物过程相互竞争和可量化的影响。当推动沙丘恢复的生物物理过程占主导地位时，岛屿往往海拔较高，对风暴的脆弱性最小。或者，当风暴侵蚀的影响占主导地位时，即使在温和的风暴条件下，岛屿也可能陷入低海拔和最容易受到风暴影响的永久状态。当海平面上升占主导地位时，岛屿就会变得不稳定，并可能面临解体。这种对屏障岛屿动态的量化得到了来自美国弗吉尼亚屏障群岛的数据的支持，并为考虑岛屿对气候变化的反应以及岛屿国家可能突然转变的可能性提供了更广泛的背景。
Barrier islands represent about 10% of the world’s coastline, sustain rich ecosystems, host valuable infrastructure and protect mainland coasts from storms. Future climate-change-induced increases in the intensity and frequency of major hurricanes and accelerations in sea-level rise,will have a significant impact on barrier islands,—leading to increased coastal hazards and flooding—yet our understanding of island response to external drivers remains limited,,. Here, we find that island response is intrinsically bistable and controlled by previously unrecognized dynamics: the competing, and quantifiable, effects of storm erosion, sea-level rise, and the aeolian and biological processes that enable and drive dune recovery. When the biophysical processes driving dune recovery dominate, islands tend to be high in elevation and vulnerability to storms is minimized. Alternatively, when the effects of storm erosion dominate, islands may become trapped in a perpetual state of low elevation and maximum vulnerability to storms, even under mild storm conditions. When sea-level rise dominates, islands become unstable and face possible disintegration. This quantification of barrier island dynamics is supported by data from the Virginia Barrier Islands, USA and provides a broader context for considering island response to climate change and the likelihood of potentially abrupt transitions in island state.