线性扩散波方程解析解及其在水位预报中的应用

提出一个可考虑回水顶托及旁侧入流影响的线性扩散波方程水位解析解模型,并对其响应函数特性进行了研究。该模型是一个集总参数的水位预报模型。模型只包括:谢才系数C和反映河道断面不规则影响的扩散系数DK,并可由试错或优化法求出。对于给定的上、下边界条件和旁侧入流,模型可快速给出各内插断面的水位过程。选用长江荆江河段1981年～1990年34次洪水资料进行参数率定,1991年～1993年7次洪水资料进行模型检验,结果令人满意。

An Analytical Diffusion Model and Its Application to Water Level Forecast

In this paper,based on the analytical solution of linear diffusion waveequation with water level,a flood routing model of channel is developed,which has clear physical significance and takes all kinds of effects (backwater and lateral inflow) in the flood wave movement into account,so that it has wide useable range.It doesn't require detailed data of cross sections or river bed geometry but requires only their average values.In this model an excellent means to analyze individual or overall effects of boundary conditions is provided.When it is applied to Jingjiang channel of the Yangte River which is a complex network with join of tributaries and distributaries as well as Dongting lake water system,it shows good results.