Acta Geographica Sinica ›› 2000, Vol. 67 ›› Issue (3): 274-280.

### Complicated Fill- scour Behaviors of the Huanghe River and the Channel forming Processes

XU Jiong xin, ZHANG Ou yang

1. Institute of Geography, Chinese Academy of Sciences, Beijing 100101
• Received:2000-02-26 Revised:2000-03-27 Online:2000-05-15 Published:2000-05-15
• Supported by:
National Natural Science Foundat ion of China and M inistry of Water Conservancy,No.59890200;key project of fundmental research of China,No.G19990436

Abstract: Based on the data from 159 flood events at the Tongguan station on the Huanghe River, we have found the rule to describe the complicated relationship between the fill scour features and the event maximum suspended concentration ( C max ). When the C max is low, the depth of scour is large. With an increased C max, the depth of scour decreases and channel fill occurs. However, when the C max further increases and enters the ranges of hyperconcentrated flows, scour occurs again. Controlled by the foregoing complicated fill scour behaviors, the channel adjustment of the Huanghe River is also complicated. When the suspended concentrations are low, channel scour occurs, and thereby the channel shape tends to be narrower and deeper, and the thalweg more sinuous. When the suspended concentration increases, channel fill occurs, leading to an increase in the channel width depth ratio and a decrease in the channel sinuosity. However, when the suspended concentration further increases and exceeds a certain threshold, channel scour occurs again, and the adjustment of channel morphology turns to the opposite direction. The rules outlined in the paper for the channel adjustment of the lower Huanghe River may provide a new thinking for the regulation of the channel morphology of the lower Huanghe River after the closure of the Xiaolangdi Dam, through the regulation of the lower Huanghe River’s water and sediment by choosing some specific operation modes of the reservoir. Either by releasing clear water or by releasing man made hyperconcentrated flows, the downstream channel may tend to be narrower, deeper and more sinuous. If some proper engineering measures are taken afterwards, the channel conditions for a better flood releasing and sediment transport may be greatly improved.

CLC Number:

• P931.1