Suspended sediment dynamics in macrotidal turbid Hangzhou Bay during Typhoon Chan-hom
Suspended sediment dynamics in macrotidal turbid Hangzhou Bay during Typhoon Chan-hom
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DOI：
10.3389/feart.2022.932149
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发表时间：
2022-08
期刊：
影响因子：
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通讯作者：
Li Li-Li;Fan-luan Shen;Zhiguo He;Zhuzhu Yu
中科院分区：
文献类型：
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作者：
Li Li-Li;Fan-luan Shen;Zhiguo He;Zhuzhu Yu
台风是一种在世界范围内造成沿海和河口地区严重社会和经济损失的极端天气事件。了解台风对沉积物动力学的影响对于保护沿海地区免受这些海洋灾害的影响至关重要。杭州湾为强潮、浊流、强台风多发海域。本文建立了一个波浪、水流和泥沙耦合的三维数值模式，并对该模式进行了验证。结果表明，台风期间悬沙浓度高值区主要分布在湾头和安东滩附近的南海岸附近。最大的底部SSC至少是近表面的两倍。由于洪峰流速较强，洪峰底含沙量（6 g/L）大于洪峰落潮（5 g/L）。在安东滩断面上，涨潮时北方海岸附近的含沙量最大，落潮时海岸附近的含沙量最大。台风通过改变海底应力场影响南海。波浪作用对SSC的影响最大，其次是风应力作用，气压作用对SSC的影响最小，分别占底应力的71.3%、69.9%和1.8%。研究结果对海岸带地貌演化研究具有重要的科学意义，对海岸带管理具有重要的现实意义。
Typhoons are extreme weather events that cause serious social and economic losses in coastal and estuarine areas worldwide. Understanding the impact of typhoons on sediment dynamics is essential for protecting coastal areas from these marine disasters. Hangzhou Bay is macro-tidal, turbid, and frequently affected by strong typhoons. In this study, we established and validated a three-dimensional model coupling waves, current, and sediment to investigate the sediment dynamics in Hangzhou Bay during Typhoon Chan-hom. The results showed that high suspended sediment concentration (SSC) areas during the typhoon were mainly located at the bay head and near the southern shore near the Andong tidal flat. The maximum bottom SSC was at least twice that near the surface. The peak bottom SSC values at the peak flood (6 g/L) were larger than those at the peak ebb (5 g/L) owing to the stronger current velocity at peak flood. The SSC near the northern shore was larger at the peak flood than at other times, and the SSC was high at the southern shore at peak ebb at the cross-section near the Andong tidal flat. The typhoon impacted SSC by changing the bottom stress. SSC was most influenced by wave action, followed by wind stress action, and was least influenced by air pressure action, which contributed 71.3%, 69.9%, and 1.8% to the bottom stress, respectively. Our findings are scientifically important for research on geomorphological evolution and are practically meaningful for coastal management.