ContextRiver channel confluences are sites of significant hydraulic and morphological change within fluvial networks (Richards, 1980;Rhoads, 1987;Ferguson et al., 2006; Lane, this volume, Chapter 3) and also occur within river channels where islands or bars are present. The local and downstream effects of confluences can have a profound influence on the geomorphology and ecology of river channels -see, for example, Rice et al.-as well as on strategies for effective channel management (Pinter et al., 2004). For these reasons, the morphology of river channel confluences is of major importance within a range of considerations and disciplines. For example, scour-depth predictions at channel junctions are clearly needed in the design of engineering structures, whilst the recognition of confluence scour is important in reconstructions of ancient sedimentary environments (Bristow et al.