HU Chun-hong, ZHANG Zhi-hao (China Institute of Water Resources and Hydropower Research, Beijing 100048, China)

Abstract: Using the methods of field data analyses and theoretical study, the separated discharge and its influencing factors is researched in the Lower Yellow River. The results show that since 1986, the channel atrophied and the separated discharge ratio of main channel have decreased, and the separated discharge ratio of floodplain increased. After 1999, due to the sluice exercise of Xiaolangdi reservoir, the Lower Yellow River scours, the passing discharge capability of main channel resume in a certain extent and the separated discharge ratio of main channel are increased, and meanwhile, the separated discharge ratio of floodplain decreased. Via establishing the relationship of the separated discharge ratio and the width, depth, area, velocity, roughness and configuration of floodplain and main channel, advices are brought forward. During the harnessing of the Lower Yellow River, a certain extent passing discharge capability and narrow deep configuration of main channel should be maintained, a certain extent passing discharge width of floodplain should be set aside, the influencing of human should be reduced in floodplain, keeping the straightway of passing discharge of floodplain, guaranteeing the passing discharge capability of floodplain, lightening the press of main channel and insuring the safety of control flood.

Key words: Lower Yellow River, compound channel, separated discharge, harnessing of floodplain and main channel

Published in: Journal of Hydraulic Engineering, Vol. 44, No. 1, 2013