信江白塔河柏泉站河段干流对支流顶托响应分析

Analysis of response of main stream to tributaries in Boquan Station section of Baita River in Xinjiang River

河道的水位流量关系直接影响着水文资料整编的可靠性,合理而准确的水位流量关系可为水文预报和水利管理提供依据,精确的水位流量关系分析对河道水情分析和防洪管理有重要意义。以白塔河柏泉水文站河段为研究对象,借助Mike21软件建立河道水动力模型,模拟河道水流动力学过程,分析洪水顶托影响下站址断面水位流量曲线和干流沿程水面线,并通过情景模拟,剖析支流洪水对干流顶托作用。结果表明:水动力模型的模拟结果与实测值基本一致,相关系数为0.98,纳什效率系数为0.85,精度满足基本要求;河道水动力学模型可较全面分析干支流交汇处的水流变化状况以及干支流洪水过程的耦合响应;支流不同洪水的洪峰和洪量对干流顶托作用明显,而且与干支流洪峰到达时间的同步性关系较大。

The relationship between water level and flow of the river directly affects the reliability of hydrological data compilation,and reasonable and accurate water level and flow relationships can provide a basis for hydrological forecasting and water conservancy management.Accurate analysis of water level and flow relationships is of great significance to river water regime analysis and flood control management.This article takes the Baita River Boquan hydrological station as the research object,use Mike21 software to establish a hydrodynamic model of the river channel,simulates the dynamic process of river flow,analyzes the water level and flow curve of the station site section and the water surface line along the main stream under the influences of flood backwater effect,and through scenario simulation,we analyze the backwater effect of tributary floods on the main stream.The simulation results show:The simulation results of the hydrodynamic model are basically consistent with the measured values,the correlation coefficient is 0.98 and the Nash efficiency coefficient is 0.85 and the accuracy meets the basic requirements.The river hydrodynamic model can more comprehensively analyze the flow changes at the intersection of main rivers and tributaries and the coupled response of the flood process of main rivers and tributaries.The flood peaks and volumes of different floods in the tributaries have obvious backwater effects on the main stream.Moreover,it is closely related to the synchronicity with the peak arrival time of main and tributary rivers.