伶仃洋西槽洪季水沙纵向输移机制研究

根据2003年实测数据,运用物质纵向输移模式计算了丰水大潮期伶仃洋西槽的水量和泥沙纵向输移量,研究了伶仃洋西槽洪季水沙纵向输移机制及水量输移特征,并针对泥沙输移特征,用底层流速和含沙量的相位变化以及表底层盐度的变化对悬沙输移机制进行了分析.结果表明:伶仃洋西槽垂向环流发育,泥沙输移特征明显;径流、潮流变形以及盐淡水异重流是形成西槽水量输移的主要原因;潮流不对称性和底层泥沙再悬浮对潮汐捕集输沙的贡献明显,盐淡水混合和纵向水体梯度对垂向净环流输沙的贡献明显.

Longitudinal transport mechanism of water and sediment in west channel of Lingdingyang Bay during flood season

Based on the measured data in 2003,the longitudinal material transport model was employed to calculate the longitudinal transport of water and sediment in the west channel of Lingdingyang Bay during ghe flood season with spring tides.With regard to the characteristics of sediment transport,the transport mechanism of suspended sediment was analyzed by use of the phase distribution of bottom velocity and sediment concentration and change of surface and bottom salinities.The results show that the vertical circulation of the west channel of Lingdingyang Bay is well developed and the suspended sediment transport is obvious. The deformation of runoffs and tidal currents as well as the density flows of saline and fresh water is the main cause for the transport of water in the west channel.The tidal asymmetry and re-suspended of bottom sediment are contributive to the tidal catching,and the mixture of saline and fresh water and the longitudinal gradient of water is contributive to the vertical circulation of net sediment transport.