Abstract:
The accurate prediction of depth-averaged streamwise velocity, boundary shear stress and lateral shear
stress are important requisites for the estimation of the flow depth associated with flood events in compound
river channels composed of main channel and floodplain. This engineering problem may be tackled
through the analytical solution of the depth-averaged momentum equation. Under uniform flow, this
solution relies on the calibration of three descriptors of the bottom friction, secondary currents and lateral
shear stress. In this paper, the analytical solution materialized in the Lateral Distribution Method is
revisited through the consideration of a new panel division. Accurate measurements of streamwise and
spanwise velocities as well as of boundary shear stress are used to obtain new predictors of the coefficients
describing the effects of bottom friction, secondary currents and lateral shear.
The new lateral division of the compound channel into four panels is physically based on the mixing
layer width, which is computed by an iterative procedure easily implemented in practical applications.
