Barrier island migration dominates ecogeomorphic feedbacks and drives salt marsh loss along the Virginia Atlantic Coast, USA
Barrier island migration dominates ecogeomorphic feedbacks and drives salt marsh loss along the Virginia Atlantic Coast, USA
复制标题
DOI：
10.1130/g38459.1
复制
发表时间：
2017-02-01
期刊：
影响因子：
5.8
通讯作者：
Kirwan, Matthew L.
中科院分区：
文献类型：
--
作者：
Deaton, Charles D.;Hein, Christopher J.;Kirwan, Matthew L.
障壁岛及其相关的backbarrier环境（盐沼，滩涂）之间的耦合导致复杂的生态地貌反馈，提出控制障壁岛系统相对海平面上升的响应。这项研究测试这些仍然是理论概念的适用性，通过调查弗吉尼亚屏障岛（美国东部），这是位于海平面上升加速的地区。使用历史地图和照片从A。D.从1851年到2010年，我们确定快速向陆地的岛屿迁移（1-6 m yr（-1））导致后障区减少和大规模盐沼损失（63 km（2）或19%），速度为0.45 km（2）yr（-1）。向陆地屏障岛迁移远远超过高地沼泽迁移，并负责沼泽损失的51%，其余的是由于后屏障过程（e。例如，在一个实施例中，边缘腐蚀）。在直接对比，建议连接屏障岛和backbarrier环境的生态地貌反馈，海岸线退缩率不相关的变化backbarrier沼泽，开放水域，或潮汐棱镜。相反，这些结果表明，屏障岛系统已经经历了迁移，主要的障碍-backbarrier耦合是沼泽和潮滩面积的损失，因为屏障岛迁移。
Coupling between barrier islands and their associated backbarrier environments (salt marsh, tidal flats) leads to complex ecogeomorphic feedbacks that are proposed to control the response of barrier island systems to relative sea-level rise. This study tests the applicability of these still-theoretical concepts through investigation of the Virginia barrier islands (eastern United States), which are located in an area of accelerated sea-level rise. Using historical maps and photographs from A. D. 1851 to 2010, we determine that rapid landward island migration (1-6 m yr(-1)) is leading to backbarrier area reduction and large-scale salt marsh loss (63 km(2) or 19%) at a rate of 0.45 km(2) yr(-1). Landward barrier island migration far outpaces upland marsh migration and is responsible for 51% of marsh loss; the remainder is due to backbarrier processes (e. g., edge erosion). In direct contrast to proposed ecogeomorphic feedbacks linking barrier island and backbarrier environments, shoreline retreat rates were not related to changes in backbarrier marsh, open-water areas, or tidal prism. Rather, these results indicate that, for barrier island systems already undergoing migration, the primary barrier-backbarrier coupling is the loss of marsh and tidal-flat area because of barrier island migration.