分汊河道水沙运动特性及其对河道演变的影响

Characteristics of water flow and sediment motion in braided river and their effects on fluvial evolution

以实测资料为依据,从理论上分析得出了稳定分汊河段的水面纵比降大于单一河段;分析了分汊河道进口段的水沙运动及输沙特性以及对汊道演变的影响;基于平衡输沙原理,分析得出了分流分沙变化对分汊河道冲淤影响的关系式,即分汊河道的冲淤演变与上游来沙量、主支汊分流分沙比及其变化等因素有关。

Based on the prototype data, the article theoretically analyzes and concludes that the water surface longitudinal slope of the stable braided river is greater than that of its single river . It analyzes characteristics of water flow and sediment motion and sediment transportation in the inlet reach of the braided river and their effects on fluvial evolution. According to the principle of sediment transportation equilibrium, a formula that describes the influences of the change of flow division and sediment division on its evolution is derived. That is to say, the evolution of the braided river is relevant to the upstream factors including sediment inflow, flow division and sediment division ratios of the braided river and their changes etc. .