Author(s): Mingwu Zhang; Heqing Huang
Linked Author(s): He Qing Huang
Keywords: Meandering rivers; Maximum flow efficiency; Equilibrium channel geometry; Sediment transport
Abstract: Rivers are self-adjusting systems and reach stable equilibrium when the condition of maximum flow efficiency (MFE), defined as the maximum sediment transporting capacity per unit available stream power, is satisfied. This is a true principle because MFE is inherent in basic flow relationships governing flow in alluvial channels. However, previous justifications on the existence of MFE are mainly made for flow in a straight alluvial channel and this study is an attempt to examine if MFE also controls flow in a meandering alluvial channel. By introducing a curved channel form factor (ratio of the radius of curvature to channel width, or rc/B) into basic flow relationships for meandering channel flow, a complex relationship between bed load sediment transport capacity and rc/B is identified. By performing a variational analysis of the relationship, primary results show that bedload transport capacity reaches a maximum when rc/B takes a definite value. A further detailed analysis is under way to uncover the general flow condition and the relevant stable channel morphology of meandering river channels.
Year: 2013