长江口南港水动力及悬沙的时空分布特征

发布时间：2018-04-30 18:12

本文选题：水动力结构 + 悬沙分布特征　；参考：《人民长江》2017年03期

【摘要】：通过2011年8月中旬一个大潮期间长江口南港某横断面上的5个定点水沙观测资料,分析了南港水动力及悬沙在潮周期及横断面上的分布特征。结果表明:在时间尺度上,南港潮位波动以半日分潮为主,日分潮较小;受径流及Stokes漂流的影响,涨潮流流速明显小于落潮流流速;含沙量随潮波动现象明显,波动频率是潮流的2倍;在空间尺度上,南港纵向流速最大值分布在南侧主槽,转流从北侧副槽率先开始;侧向流主要是由科氏力对纵向流的偏转作用形成;北侧副槽平均含沙量大于南侧主槽;半日潮流驱动下,平均含沙量在急流和憩流时刻将分别增大和降低;半日潮流和余流共同驱动下,在落急时刻和涨急时刻分别会增大和降低平均含沙量。
[Abstract]:Based on the observation data of water and sediment at five fixed points on a cross section of the South Port of the Changjiang Estuary during a spring tide in the middle of August 2011, the characteristics of hydrodynamic force and suspended sediment distribution on the tidal cycle and cross section of the South Port are analyzed. The results show that, on the time scale, the tidal level fluctuation in the south port is mainly semi-diurnal, and the diurnal tidal component is small, and the tidal current velocity is obviously lower than that of the falling tidal current under the influence of runoff and Stokes drift, and the sediment content fluctuates with the tide obviously. The frequency of fluctuation is 2 times that of tidal current, on spatial scale, the maximum longitudinal velocity of Nangang is distributed in the main channel of the south side, and the diversion begins from the secondary trough on the north side, and the lateral flow is mainly formed by the deflection of Coriolis force to the longitudinal flow. The average sediment content of the north side secondary trough is larger than that of the southern main channel; the mean sediment concentration will increase and decrease at the time of the jet current and the open flow under the driving force of the half day tidal current, and the half day tidal current and the residual current together drive, The average sediment content will increase and decrease respectively at the time of falling and rising.
【作者单位】：三峡大学水利与环境学院;上海地质调查研究院;
【基金】：国家自然科学基金项目(41506103) 三峡大学博士人才启动基金项目(KJ2014B032)
【分类号】：TV148

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