太湖流域平原河网分流比影响因素

以太湖流域典型分汊河道为例,构建河道二维水动力模型,研究平原河网分流比主要影响因素及其作用机理,并运用岭回归建立了平原河网分流比预测方程。结果表明:平原河网分流比与糙率、支汊过水宽度比、水位差呈正相关关系,与干流流量呈负相关关系,与分汊角度关系复杂;干流流量和支汊过水宽度比是影响分流比的主要因素;构建的多因素平原河网分流比综合预测方程可用于预测平原河网分汊河道分流比。

Influencing factors of flow diversion ratio in plain river networks of Taihu Lake Basin

Taking the typical branching channel in Taihu basin as an example, a 2-D hydrodynamic model of river channel was constructed to study the main influencing factors and mechanism of flow diversion ratio in plain river networks, and a prediction equation of diversion ratio for plain river networks is established by ridge regression. The results show that the flow diversion ratio of plain river networks has a positive correlation with roughness, ratio of the width of the tributary to that of the main Channel and water level difference, while a negative correlation with the main stream discharge, and a complicated relationship with the branching angle. The discharge of the main stream and the ratio of the width of the tributary to that of the are two dominant factors of the flow diversion ratio. The multi-factor comprehensive prediction equation for the flow diversion ratio of plain river network can be used to predict the flow diversion ratio of braided rivers in plain river networks.