强潮河口上游建库引水后的再造床过程

Fluvial process of establishing new equilibrium in river section upstream of strong tide estuary due to constructed reservoirs

作者以鳌江河口为例,应用一、二维耦合潮流泥沙数学模型,研究了上游河道建库引水后河口的再造床过程。文中分析了该河口的水文、泥沙特性及河床演变规律;给出了数学模型的计算条件、关键问题的处理方法和验证计算结果;预测了建库引水后河口的水流和河床变化过程。研究表明:水库运用初期淤积发展很快,以后逐渐减小,直至建立新的平衡;淤积是自上而下发展的,且沿程分布不均匀,弯道段淤积厚度相对较小,位于两弯道的过渡段淤积厚度相对较大;淤积在断面上的分布也不均匀,泥沙淤积对河口地区的港口及航道水深有一定影响。

The fluvial process of establishing new equilibrium in river section upstream of Aojiang River estuary due to constructed reservoir is studied by means of 1-D tidal flow-sediment mathematical model coupling with 2-D model.The characteristics of hydrology,sediment transport and fluvial process are analyzed.The calculation condition, the techniques for solving some key problems and verification of computation results are presented.The flow and fluvial process are predicted.It is found that the aggradation develops rapidly in the early stage after construction of reservoirs and it tends to degrade afterward until a new equilibrium is established.The aggradation process develops from upstream to downstream and the thickness of deposition at the river bend is smaller than the transition section between two bends.The water depth of navigation at the port will be affected by the sediment deposition.