Earth Surf. Dynam. Discuss., https://doi.org/10.5194/esurf-2019-8 Manuscript under review for journal Earth Surf. Dynam. Discussion started: 27 February 2019 c Author(s) 2019. CC BY 4.0 License. Experiments on patterns of alluvial cover and bedrock erosion in a meandering channel Roberto Fernández1, Gary Parker1,2, Colin P. Stark3 1Ven Te Chow Hydrosystems Laboratory, Department of Civil and Environmental Engineering, University of Illinois at 5 Urbana-Champaign, Urbana, IL 61801, USA 2Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA 3Lamont Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA Correspondence to: Roberto Fernández (
[email protected]) Abstract. 10 In bedrock rivers, erosion by abrasion is driven by sediment particles that strike bare bedrock while traveling downstream with the flow. If the sediment particles settle and form an alluvial cover, this mode of erosion is impeded by the protection offered by the grains themselves. Channel erosion by abrasion is therefore related to the amount and pattern of alluvial cover, which are functions of sediment load and hydraulic conditions, and which in turn are functions of channel geometry, slope and sinuosity. This study presents the results of alluvial cover experiments conducted in a meandering channel flume of high fixed 15 sinuosity. Maps of quasi-instantaneous alluvial cover were generated from time-lapse imaging of flows under a range of below- capacity bedload conditions. These maps were used to infer patterns