长江河口涨潮槽泥沙运动规律

30年来，在对涨潮槽性质和水沙条件有所了解的基础上，于2001年洪季和2003年枯季又一次对长江口新桥水道和南小泓两条典型涨潮槽及与其相邻的南支和南港主槽(落潮槽)的水流、泥沙和河床沉积物进行观测，并进行了专题研究。结果表明：潮流历时涨潮比落潮短；潮流和单宽潮量涨潮比落潮大，优势流小于50％，净水流向槽顶方向：涨潮含沙量、单宽输沙量大于落潮，优势沙小于50％，净输沙向槽顶方向；悬沙粒径组成较细，河床泥沙粒径组成较粗，河床存在推移质泥沙运动，并形成微地貌沙波。

Sediment transport in flood channels of the Changjiang estuary

Field observations and sampling were conducted at two typical flood channels of Xinqiao and Nanxiaohong channels in the flood season of 2001 and the dry season of 2003, respectively. The field measurements include tidal currents, suspended sediments, bed materials and bed forms. Results show that (a) the flood tidal duration is shorter than the ebb tidal one; (b) tidal currents and their water fluxes during the flood period are larger than those during the ebb period, and the predominant flows are estimated to be less than 50%, so the net water load is discharged upstream of the flood channels; (c) the suspended sediment concentrations and fluxes during the flood period are larger than those during the ebb period, and the predominant sediment discharges are estimated to be less than 50%, so the net sediment loads are transported upstream of the flood channels; (d) suspended loads are composed of fine-grained sediments, and bed material loads are coarse-grained sediments. The bed load can move in a group as sand waves.