复式河道水流运动模型的研究与应用

Research and Application of Compound River Flow Movement Model

针对复式河道的特点,建立了主槽和滩地同时演进的复式河道水流运动数学模型,采用四点线性隐式离散圣维南方程组进行主槽水流模拟,用曼宁公式模拟滩地水流运动,针对主槽和滩地的不同涨落现象,提出用概化溢流堰模拟主槽和滩地之间水量交换的方法,并将此模型应用于蚌埠—花园嘴的淮河干流段,以1982年和1991年汛期洪水过程进行了验证,并与断面平均流速法和调蓄宽度法进行了比较。结果表明:模型的计算结果相比断面平均流速法和调蓄宽度法有洪峰流量相对误差和峰现时间误差均较低的优点,说明该模型模拟精度较高,能很好地模拟复式河道的水流运动情况。

According to the characteristics of the compound river channel,a mathematical model of flood in main channel and in flood plain routing at the same time was established. For the main channel flow simulation the Saint-Venant equations were adopted by use of the Preissmann weighted implicit four-point scheme and the Manning formula was used to simulate the water movement in the flood area. In view of different fluctuation phe-nomenon of the main channel and the beach,a method using the generalized broad crested weir to simulate the water exchange between the main channel and flood area was proposed. It applied this model to simulate the 1982’s and 1991’s flood in the reach from Bengbu to Huayuanzui of the Huaihe River. Compared with the method of average velocity of area and the regulate width method,the results show that,this model is lower in relative error of flood water flow and time error of peak current. It has the higher accuracy of simulation and can better simulate water movement of compound river channel.