Winter storms induced high suspended sediment concentration along the north offshore seabed of the Changjiang estuary
Winter storms induced high suspended sediment concentration along the north offshore seabed of the Changjiang estuary
复制标题
冬季风暴导致长江口北岸海底悬浮泥沙浓度较高
DOI：
10.1016/j.ecss.2019.106351
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发表时间：
2019-11
期刊：
影响因子：
--
通讯作者：
Wu Hao
中科院分区：
文献类型：
--
作者：
Tang Jieping;Wang Ya Ping;Zhu Qingguang;Jia Jianjun;Xiong Jilian;Cheng Peng;Wu Hui;Chen Dezhi;Wu Hao
近岸沃茨中悬浮的细粒沉积物对海底地形演变及环境变化起着重要作用。悬浮泥沙在海底附近集中汇聚，形成高含沙量，对泥沙输移有重要作用。为探讨长江口高悬浮泥沙浓度（SSC）的形成机制，于2015年12月20日至2016年1月20日在长江口北方布设三脚架和浮标，分别在海底和海面采集了底质边界层泥沙动力学和气象及波浪资料。在小潮期间，当冷空气入侵产生冬季风暴和大浪时，在海底附近观察到高SSC（例如>3 g/L）事件和流体泥浆（厚度为4-16 cm）。进一步研究发现，高SSC事件主要是由风浪和沉积物再悬浮引起的，并与三个阶段相关联。在建立阶段，冬季风暴带来了长时间的强波（如有效波高> 1.5m），持续时间超过15 h，导致最大波流联合底切应力达到3.2Pa，悬浮物浓度增加到> 1g/L。在强化阶段，强波浪和底切应力持续数小时，使悬浮物进一步增加到> 3g/L。在衰减的最后阶段，风浪和最大波流切应力显著减小，高SSC消失。因此，有没有高SSC事件观察到，即使在大潮强风波，因为强波持续时间太短的加固过程。高SSC事件的沉积物来源主要是来自底层流体泥浆的再悬浮，以及邻近的长江水下三角洲的平流输送。
Fine-grained sediments suspended in coastal waters play an important role in submarine topography evolution and associated environment changes. The convergence of suspended sediments concentrated near the seabed results in high sediment concentration, and contributes significantly to sediment transport. In order to investigate the mechanism triggering high suspended sediment concentration (SSC), we deployed a tripod to the seabed to obtainin situbottom boundary layer measurements of sediment dynamics and a buoy to the sea surface to collect meteorological and wave data at the northern Changjiang River mouth from December 20, 2015 to January 20, 2016. The high SSC (e.g. >3 g/L) events were observed together with fluid mud (thicknesses of 4–16 cm) near the seabed during neap tides when cold air intrusion generated winter storms and strong waves. Further, we found that the high SSC event was mainly resulted from wind waves and sediment resuspension supported by local benthic fluid mud, which was associated with three stages. At the setting up stage, the winter storm brought long duration of strong-waves (e.g. significant wave height >1.5 m) more than 15 h, resulting in a maximum wave-current combined bottom shear stress of 3.2 Pa and the increase of SSC to >1 g/L. At the reinforcement stage, the strong waves and bottom shear stress lasted for several hours, and further increased the SSC to >3 g/L. At the final decay stage, wind waves and the maximum wave-current shear stresses decreased significantly, with the disappearance of high SSC. Thus, there was no high SSC event observed even with strong wind waves during spring tides because strong wave duration was too short for the reinforcement process. The sediment source for the high SSC events was mainly from bottom fluid mud resuspension, as well as the advection transport from the adjacent subaqueous Changjiang River delta.
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影响因子：
9.9
作者：
S. F. Chen;R. Chan;Stanley M. Read;L. A. Bromley
通讯作者：
S. F. Chen;R. Chan;Stanley M. Read;L. A. Bromley
影响因子：
3.9
作者：
Z. Dai;James T. Liu;Gui Fu;Hua-liang Xie
通讯作者：
Z. Dai;James T. Liu;Gui Fu;Hua-liang Xie
影响因子：
--
作者：
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通讯作者：
S. Bass;J. Aldridge;I. McCave;C. Vincent
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影响因子：
3.6
作者：
Luo Zhifa;Zhu Jianrong;Wu Hui;Li Xiangyu
通讯作者：
Li Xiangyu
影响因子：
2.3
作者：
Qian Yu;Y. Wang;B. Flemming;Shu Gao
通讯作者：
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