CONCEPTUAL MODEL OF RIVER ICE TYPES AND DYNAMICS ALONG SEDIMENTARY LINKS

This paper proposes a conceptual model relating the large-scale distribution of river ice types and dynamics to the longitudinal sequence of river forms and flows typically encountered along the sedimentary links of gravel-bed rivers. Sedimentary links are discrete river segments each characterized by a node of coarse sediment recruitment followed by a gradual downstream fining of substrate and an associated reduction of channel slope. Because these downstream changes in substrate and slope are associated with changes in channel morphology and hydraulics, they create a longitudinal sequence of river environments moving from steep, fast flowing and highly turbulent boulder bed channels at the head of links to meandering low-gradient sand channels with calm flows at the downstream end. We describe and show examples of how these spatial variations in the geomorphology and flow characteristics of gravel-bed rivers should interact with river ice processes to produce a predictable 'most probable' large-scale pattern of river ice types and dynamics. Copyright (C) 2011 John Wiley & Sons, Ltd.