洪水演进中支流倒回灌研究

在处理洪水演进过程中支流与干流洪水的相互影响时，以前的模型仅将支流流量迭加到干流同时刻的流量上，事实上，支流对干流洪水有调蓄作用，对陡涨陡落的溃坝洪水而言，这是不可忽视的重要因素。依据水量平衡原理及水流连续性条件，建立了支流蓄泄库容关系和支流倒回灌数学模型，将该模型应用于历史上某次垮山堵江溃决洪水，得到的计算结果与实测资料和洪痕数据相吻合。研究结果表明在干支流交汇口，干流流量变化速率越大，支流倒灌

Study on Lateral Flow Exchange Between Tributary and Main Channel During Flood Routing

When dealing with the relationship between tributary and main channel during flood routing, the general method is to add the discharge of tributary to that of main channel of the same instant. In fact, the tributary acts as a conditioning reservoir, which is an important factor to sudden flood caused by dam collapse. in this paper, a mathematical moder for the flow exchange between tributary and main channel is proposed based on water equilibrium and flow continuity condition. When the model is applied to a historical dam break flood, the computational results agree well with hydrographic station records and flood tracking investigation. The results also show that the lateral flow exchange between tributary and main channel is proportional to the variation rate of the discharge in main channel. Moreover, attentions must be paid to the tributary with slight slope bed, because the water flowing into the tributary from the main channel during the uprising period of main channel flood may cause large scale inundate in the tributary basin.