Preissmann隐式差分格式在渭河下游洪水演进计算中的应用

Application of the priessmann implicit scheme to flood routing in lower Weihe River

针对渭河下游河道的特点，利用Preissmann四点加权隐式差分格式对圣维南方程组进行离散，求解洪水的传播过程。文中对差分方程各项系数中的全微分项dA／dz、dB／dz、da／dz和dK／dz的散离方法进行了讨论，给出了较为有效的数值计算方法。利用渭河下游临潼至华阴河段1983年9月底的实测洪水过程对模型的验证计算结果表明，水位和流量过程计算值与实测值均吻合较好，所提方法是合理可行的。

This paper presents an efficient numerical method by using Preissmann implicit scheme in dispersion the De Saintvenant equations, which is based on the characteristics of the lower Weihe river. Discussions focus on the dispersion and calculation methods of the derivative terms in the coefficients of dispersed equations. The model is calibrated by using of the measured data on the reach between Lintong and Huayin of Weihe river in September 1983. The computed water levels and discharges agree with the measured ones. The computed results are reasonable.