Fluvial Processes of the Lower Yellow River and Estimation of Flood Conditions

Abstract

The Yellow River is a famous river that carries sediment at hyperconcentrations. On average, the runoff volume at the Huayuankou HydrographiC Station is 47 billion cu.m annually, only one-twentieth of that of the Yangtze River, and the annual mean sediment discharge is 1.6 billion tons, 3 times as much as the Yangtze River. The disequilibrium between runoff and sediment discharge seems to be the crux of the problem which causes sedimentation and a rising bed in the lower Yellow River, gradually making the Yellow River a “Hanging River,” and causing frequent abnormal or catastropic floods, avulsions and diversions. In the last 30 years, the annual mean accretion rate in the lower Yellow River has been about 10 cm/y, resulting in a situation where the difference in height between the nearby ground surface inside the banks and outside the banks is 6–8 m in the reach from Huayuankou to Dongbatou, and 3–5 m in the reaches downstream from Dongbatou. It is very important and urgent to study the processes of the evolution of the Yellow River further and to estimate flood conditions in advance.