长江中游戴家洲河段河床演变分析及趋势预测

Alluvial process analysis and trend prediction of Daijiazhou reach in middle Yangtze River

戴家洲河段来水来沙特点分析表明,本河段具有明显的平原河流特征,水流易受地形影响,河段年际间来水来沙存在较大的变化,来沙以流域产沙为主,河段内造床起主导作用的是悬移质泥沙运动。河段演变特点主要表现为:洪水河势基本稳定而中低水滩地则冲淤变化不定;池湖港心滩基本稳定;巴河边滩发育和冲蚀交替;戴家洲洲头不断变化;直港直水道和微弯水道特征不断转化交替;巴河边滩的消长、戴家洲洲头的进退和直港滩槽演变密切相关;戴家洲直港浅滩位置多变且呈洪淤枯冲规律。结合三峡水利枢纽的蓄水运用,对戴家洲河段河床演变趋势进行了预测。

The characters of runoff and sediment of Daijiazhou reach in middle Yangtze River is analyzed.It shows that the plain river characteristics of Daijiazhou reach is obvious.The runoff and sediment verify greatly for each year.The suspended load plays an important role in alluvial process.The characters of river evolution are as follows：the flood river regime is stable whereas the low-water riverbed is unstable;the Chihugang shoal is basically stable;the deposition and erosion of Bahe point bar is alternating;the head of Daijiazhou sandbar is constantly changing;Zhigang channel alternate between slightly curved channel characteristics and straight channel characteristics;Bahe point bar and the head of Daijiazhou sandbar are closely related to Zhigang channel condition;the position of Zhigang shoal is frequent changing;Combined with impoundment of the Three Gorges Dam,the fluvial trendency of Daijiazhou reach is predicted.