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基于2011年洪季在南支河道从小潮至大潮连续8天现场定点观测所获得水沙观测数据(包括潮流、悬沙浓度、悬沙粒度和表层沉积物样品),通过对悬沙浓度、悬沙粒度和沉积物在不同时刻的组成分析,以及流速、悬沙和底床切应力的相互影响分析,对长江河口南支河道悬沙随时间变化特性和河床沙再悬浮作用进行了研究。结果表明:观测期间南支主槽下段落潮水动力强于涨潮;落潮悬沙浓度高于涨潮,并由小潮至大潮逐渐增加;落潮悬沙粒径粗于涨潮,并随小潮至大潮不断粗化;河床沉积物颗粒较粗,细砂类组成达到90%以上;流速、悬沙及底床切应力之间存在显著相关性;河床泥沙再悬浮强度较强,其量值有限。而近期研究区域悬沙浓度和水沙关系发生变化,与流域来沙出现锐减有关。
Based on the observed data of water and sediment (including tidal current, suspended sediment concentration, suspended sediment concentration and surface sediment samples) from the fixed point observation of small tide to tidal wave in the Nanchian River in 2011 during the flood season, Sand composition and sediment composition at different times, as well as the interaction between flow velocity, suspended sediment and bed shear stress were analyzed. The characteristics of suspended sediment with time and the sediment resuspension in the Nanzian River of the Yangtze Estuary were studied. The results show that during the observation period, the hydrodynamic force in the lower section of the main branch of the south branch is stronger than that in the high tide; the concentration of suspended sediment in the ebb tide is higher than that of the high tide and gradually increases from the tidal tide to the tide; the particle size of the ebb suspension is thicker than the tidal wave, ; Sediment particles in the river bed are coarse, and the composition of fine sand reaches more than 90%; there is a significant correlation between flow velocity, suspended sediment and bed shear stress; sediment resuspension strength in the river bed is strong, and its value is limited. Recently, the relationship between suspended sediment concentration and water and sediment changes in the study area has been related to the sharp drop in the sediment yield from the basin.