长江下游黑沙洲南水道河床演变及碍航特性

依据河道实测水文、地形资料对长江下游黑沙洲水道河床演变和碍航特性进行深入分析,初步提出该河段的航道整治思路。分析表明:大水年尤其是特大洪水年,河床冲淤变化相对较大,南水道过渡段左槽冲刷、右槽中下段淤积现象明显。主要原因是洪水期南水道过渡段漫滩水流增强,左槽分流沿程增加、右槽分流沿程减小,江中心滩束流作用有限,处于缓流区的右槽下段输沙能力不足,汛后冲刷不充分。航道整治的基本思路为稳定相对有利的滩槽格局,拦截漫滩水流、限制左槽的进一步冲刷发展、增强南水道右槽水流的冲刷能力。

Riverbed evolution and navigation obstructing characteristics at Heishazhou Southern Waterway downstream the Yangtze River

Based on analysis of topographic and hydrological data,we run an extended analysis of the characteristics of the riverbed evolution as well as the navigation obstructing at the Heishazhou Southern Waterway downstream the Yangtze River.The thought of waterway regulation is put forward.It shows that the change of erosion-deposition variation is relatively large when encountered flood years.The left channel scours and the middle and lower of right channel silt.The main reasons are that the overbank flow in the transition section of the channel increases during the flood period,division ratio of left channel increases along the way but right channel decreases,the central bar of the South channel bounded water flow limitedly,sediment transporting capacity in subcritical flow area of the right channel is insufficient and the scouring is not sufficient after the flood season.The basic idea of channel regulation should be to stable the favorable terrain pattern,intercept the overbank flow,limit the further development of the left channel erosion,and enhance the scouring of the right channel of the South Waterway.