弯曲分汊河段浅区成因研究

Study on cause of shallow beach in meandering and braided river

为解决弯曲分汊河段航道治理的关键问题,选取长江中游监利河段,采用调研与实测资料分析、理论研究、水槽概化模型试验等手段,给出了弯曲分汊河段水流脉动动能的分层平面等值线图,揭示了分流区浅滩形成的内在机理,给出了弯曲分汊河段沿程水流挟沙力变化情况。表明分流区底部水流的脉动动能比较分散,得出水流挟沙力在分流区最小,这也是分流区浅滩形成的原因之一。

In order to solve the key technologies of river regulation,the meandering and braided river at Jianli reach in the middle Yangtze River was studied in this paper.Through investigated and measured data analysis,theoretical research,flume generalized model tests and the other technical methods,the stratification plane isopleth map of fluctuating kinetic energy for the meandering and braided river reach was given.The formation mechanism of the shoal was revealed,and the variation of sediment carrying capacity was also given.It is shown that the fluctuating kinetic energy of the bottom current in the bifurcation region is scattered.The minimum value of sediment carrying capacity is in the bifurcation region,and that is one of the reasons of formation for the shoal.