Time-averaged flow structure in the central region of a stream confluence:A discussion

This paper is a discussion of Rhoads and Kenworthy ( 1998) 'Time-averaged f low structure in the central region of a stream confluence' Earth Surface P rocesses and Landforms, 23, 171-191, that focuses upon the methods used to identify secondary circulation in river channel confluences, It argues that the Rozovskii method that Rhoads and Kenworthy use to rotate their field d ata to allow identification of secondary circulation cells is flawed, and c an result in misleading conclusions about the nature of flow processes in c onfluences. It recommends that there is a re-emphasis upon helical as oppos ed to secondary circulation, and that recent developments in both field mon itoring and numerical modelling may help significantly in this respect. Cop yright (C) 1999 John Wiley & Sons, Ltd.