Erosion and siltation processes in the lower yellow river during different river courses into the sea

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 m ³/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.