Flow and Bed Profile in Meandering Sand‐Silt Rivers

Abstract

Mathematical models for defining three‐dimensional flow and bed topography in sinuous channels with suspendable bed material are presented. It is shown theoretically that the secondary flow in sinuous channels shows a reduction in its magnitude below that of a uniformly‐curved channel, and also displays a phase‐lag relative to the channel plan‐form. The model for bed topography is derived by considering the sediment balance for bed load and suspended load, the transport rate and direction, all of which are governed by the three‐dimensional flow. A laboratory test supports the model. The present study has made it possible to predict the large‐scale bed topography of meandering sand‐silt rivers, including such features as the magnitude and the location of local scour and point‐bar deposits.