Characterizing and identifying bedforms in the wandering reach of the lower Yellow River  

作　　者：Yuanfeng Zhang Ping Wang Guanqing Shen 

机构地区：[1]Yellow River Institute of Hydraulic Research,Zhengzhou,Henan,450003,China

出　　处：《International Journal of Sediment Research》2022年第1期110-121,共12页国际泥沙研究（英文版）

基　　金：supported by the National Research and Development Program of China(Grant No.2017YFC0405505);Basic Research Fund for Central Public Interest Scientific Institutes(Grant No.HKY-JBYW-2017-07);the National Natural Science Foundation of China(Grant No.51379087).

摘　　要：The lower Yellow River(LYR)is a fully alluvial system with a fine-grained bed that has a high proportion of silt.Bathymetric survey data collected with a Multi-Beam Echo Sounder(MBES)from the wandering reach of the LYR indicates that the bedforms are characterized by large aspect ratios(wavelength/height)and low lee-side angles.Since the Xiaolangdi Reservoir(XLD)has been operational in the middle reach of the Yellow River,bedforms have been dominated by two-scales of dunes,that is,a frame of compound dunes with first-order dunes superimposed on the stoss and lee sides,which disappear during high sediment concentration floods that occur during the annual sediment and water regulation.The bedform formation regime has changed with dune beds having more chances,and upper regime beds having less chances,to form.Longitudinal profile data measured using a sounding-rod before the XLD began filling demonstrate that the bedforms were mainly dunes during low flows(less than 1200 m3/s)or upper regime beds during high-flows(larger than 2000 m^(3)/s).A discriminator is proposed to describe the conditions for bedform formation and to predict the alluvial resistance which gives better results than those from Manning approach.When a bedform system is almost at equilibrium,the changes in the sediment concentrations versus the discriminator can be defined into three segments in the LYR.

关 键 词：Bedform discrimination Two-scales of dunes Alluvial resistance The lower Yellow River 

分 类 号：TV143[水利工程—水力学及河流动力学]