一维河网模型断流问题研究

在枯水季节的河网中,常常存在断流的问题。为了计算河网区域水沙数学中断流对分流量以及冲淤量的影响,本文提出了一种修正零流量法来模拟河网中的断流现象。该方法综合了虚拟断面法和零流量法的优点,可以根据断流判定条件修正汊点矩阵。这种新的断流计算方法被应用于荆江洞庭湖河网区域,模拟了三口的分流规律,并取得了较好的结果。该方法可以有效避免虚拟断面法枯水季分流量过大和零流量法易致汊点矩阵奇异。

Study on zero flow with one-dimensional numerical model of river channel network

Zero flow often occurs in river channel network in dry season.This paper presents an amended zero flow method for simulation of the impact of zero flow on flow splitting,siltation and erosion.This method combines the advantages of virtual flow area method and zero flow method,and it can correct coefficient matrix according to the zero flow conditions.The new method was applied to the Jingjiang-Dongting Lake region downstream the Three Gorges project to study the flow diversion features of the three lake outlets under the condition of zero flow discharge.The calculations of water level and flow discharge agree well with the measurements.The method avoids excessive estimation of split flow discharge by virtual flow area method and the singular coefficient matrix of zero flow method.