The Evolution Rule And The Experimental Study Of Bifurcated River Downstream The Water Control Project

The bifurcated channel is a common river type in natural rivers. The middle and lower reaches of the Yangtze River is typical bifurcated river.the evolution rule of bifurcated river is a burnning topic which has not been solved. The evolution rule of bifurcated river is influenced by several factors. With the human being's activities, there have been great changes of the water and sediment before and after the construction of Water Control Project in rivers especially. Accordingly, the research on the evolution rule of bifurcated river downstream the dam is significant and has practical value.This paper firstly summarize Situation of Study on evolution rules of bifurcated river domestic and overseas, inductively analysis the typical Water-sediment movement of the bifurcated river in the middle and lower reaches of Yangtze River, analyzes the conditions that conducive to the stability of the turnout track of the river. And then with water and sediment variation of points, the paper analyzes the scour rule and the characteristics of the coming water and sediment at the downtown streams of the Three Gorge dam according to the measured data in Jianli reach of the Three Gorges. This paper discusses the influence on the development tendency of main reach which may caused by the different river bed .Designing and producing physical model of Yaojian reach, that simulated characteristics and trend among three different riverbed. Through comparison and analysis, we believe that good inflow conditions and lower elevation makes for shunt in conditions that hydro-junction is operating, the two kinds of riverbed form are good for the development of branching, conclusion believe that smaller deflection angle is also a advantage to the development tendency of bifurcated river after reservoir completed. This paper has also established 2-d sediment mathematical model, contrasting the calculation results with a physical model results, we get the good agreement with physical model of the same conclusion.