一维圣维南方程组在非恒定流计算中的应用

天然情况下，河道水流在某河段内可能是恒定流，亦可能是非恒定流。一般地，山区性河流多视为恒定流，但在河道干支流的汇合口、河道与湖泊的交汇处、以及潮汐河段等处的水流常常为非恒定流。对于非恒定流， 用常规的水文学方法难以分析计算出河道水流的各个水文特征值，圣维南方程组则是解决此类问题的途径之一。运用圣维南方程组建立一维数学模型，应用芙蓉江江口水文站、长江徐六烃水文站实测水文资料进行分析验算，对解决非恒定流方面的一些实际的水文问题进行初步分析和探讨。

Application of one dimensional Saint-Venant equations in non-constant flow

Under natural conditions,flows in a river stretch can be both steady and unsteady.In general,flows in mountain rivers are mostly regarded as steady,and flows in confluences of a main stream and its contributory streams,in confluences of river and a lake as well as in tidal river reaches are often unsteady.For unsteady flows,conventional hydrological methods are hard to analyze and compute all hydrological characteristic values of a river flow.St.Venant equation system is one of the approaches to solving this kind of problems.A one-dimensional mathematical model is developed by using St.Venant equation system.Hydrological data observed at the Jiangkou hydrological station on the Furong river and the Xulujing hydrological station on the Yangtze river are used to analyze and check the data obtained from the model.Some practical hydrological problems related to unsteady flows are preliminarily analyzed and explored.