黄河下游河床平面变形模拟研究

Numerical simulation of riverbed horizontal variation for the lower reaches of Yellow River

黄河下游河道以游荡多变著称，河床演变具有典型的平面二维特征，本文分析了黄河下游河床横向变形的基本模式，认为河床的横向变形是由泥沙的侧向冲刷和河岸淘蚀综合作用的结果，数学模型中可通过这两种现象的分别模拟反映实际河岸的横向变化．引进土力学中有关河岸力学平衡的基本关系，结合河床演变计算的特点在数值方法上适当简化，提出了黄河下游河床横向变形的数值模拟方法，采用反映高含沙水流流动特性的基本方程组。

This paper gives a special treatment on the river bed adjustment mode,especially for the horizontal variation.According to the data from Yellow River,the horizontal variation of riverbed can be divided into two parts,i.e.erosion at the toe of a bank and collapse of bank.Based on the analysis on the equilibrium of the forces,a new method for simulating the horizontal variation of the riverbed is proposed.The validity of the method is verified by the observed data in 1977 referring to a typical high sediment laden flood which peak concentration reached 546kg/m 3.