不同流路时期黄河下游河道的冲淤变化过程

Erosion and Siltation Processes in the Lower Yellow River during Different River Courses into the Sea

运用统计学方法对1950-2007年的水沙数据以及不同流路各水文站同流量(3000m3/s)水位变化进行了分析,结果表明:黄河下游河道表现出淤积—冲刷交替出现的变化过程,当进入下游的含沙量为18.6kg/m3时,河道冲淤表现为动态平衡。艾山以下河道的冲淤变化过程除受水沙条件控制外,还受到流路变迁的影响。流路变迁初期河道发生溯源冲刷作用,中后期河道发生溯源淤积作用。各站同流量水位变化,神仙沟流路主要为下降,河道以冲刷为主;刁口河流路主要为升高,河道以淤积为主;清水沟流路有升有降,河道冲淤互有,总体表现为淤积。流路变迁对河道横断面形态的影响主要在利津以下。

There are distinctive responses of the lower Yellow River to water-sediment variation, and river course transfer into the lower reaches have been changed notably since 1950 due to the water-sediment conditions, which is the result of human activities and climate changes, and the river course into the sea has been transferred several times. The paper analyzed the water-sediment data （1950-2007） and the water level variation under the same flow （3000 m3/s） at hydrological stations in different courses into the sea. Results show that the lower Yellow River has displayed an alternation between siltation and scouring. It would keep a dynamic balance when the suspended sediment concentration into the lower reaches is about 18.6 kg/m3. Besides controlled by water-sediment with siltation or scouring, the variation process of reaches downwards Aishan has been affected by river course transfer. The reaches have experienced upriver scouring in early days of river course transfer and it has exhibited upriver siltation as the extension of river mouth in mid-and late periods of transfer. During the survival time of Shenxiangou course, the water level variation under the same flow at hydrological stations has descended mainly with the characteristic of erosion in the reaches.