“…In recent d ecades, the three-dimensional flow structure, turbulence characteristics and secondary flows in straight compound channels have been extensively investigated by, amongst others, Knight and Demetriou [14], Pasche and Rouve [25], Knight and Sellin [15], Tominaga et al [41], Yuen [45], Carling et al [3] and Yang et al [43]. Moreover, lateral distribution methods (LDM) for the depth-averaged velocity and bed shear stress, along with the secondary flow and the planform vorticity, have been developed by Shiono and Knight [31], Cao et al [2], Rameshwaran and Shiono [29], Huai et al [9], Hu et al [8],Liu et al [20] and Yang et al [44]. These researchers showed that the secondary flows affect the predictions of velocity and bed shear stress significantly and ignoring them leads to poor results.…”