Estuarine morphology recovery after the 2011 Great East Japan Earthquake Tsunami
Estuarine morphology recovery after the 2011 Great East Japan Earthquake Tsunami
复制标题
2011年东日本大地震海啸后河口形态的恢复
DOI：
10.1016/j.margeo.2018.01.001
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发表时间：
2018
期刊：
影响因子：
2.9
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
Hong;V.C.;Tanaka;H.;Mitobe;Y.
2011年东日本大海啸造成日本东北部受影响海岸线沿着严重的地貌变化。本研究以日本宫城县为研究对象，通过航片分析和实地调查，研究了海啸造成河口严重侵蚀后，河口的恢复和桑迪海岸的溃决情况。海啸发生几年后，一些河口的形态已基本恢复，而另一些河口仍有一定的破坏。航片分析结果表明，河口两侧桑迪海岸的总长度在恢复过程中起着重要作用。此外，形态恢复过程中发生的相关现象也进行了研究。调查结果表明，由于海啸对河口的冲刷深度超过了河口的封闭深度，沙嘴侵入河口。有趣的是，入侵距离被发现与河口的宽度呈正相关。此外，在与沙嘴上游入侵有关的实际问题上有一个重要的发现。这种入侵使淡水的边界向上游移动，因此在实施河流结构物设计时必须考虑外部波浪力。
The 2011 Great East Japan Tsunami caused severe morphological changes along the affected coastline on the northeast part of Japan. This study investigates the recovery of river mouths and breaching of sandy coast at the place used to be river mouth in Miyagi Prefecture, Japan after severe erosion induced by the tsunami through analyzing aerial photograph and investigating field data. After several years since the tsunami took place, the morphology of some river mouths has mostly recovered while others still have some damage. Results on the analysis of aerial photograph clearly indicate that the total length of sandy coast on both sides of river mouth plays important role in the recovery process. Moreover, the relevant phenomenon occurring during the morphological recovery process is also investigated. The findings demonstrated the intrusion of sand spit into river mouths due to the tsunami having scoured river mouth deeper than the depth of closure. Interestingly, the intrusion distance was found to be positively correlated with the width of river mouth. In addition, there is an important finding on the practical problem which is related to the intrusion upstream of sand spit. That intrusion shifts the boundary of fresh-sea water upstream, therefore external wave forces must be considered when implementing the design of river structures.