Channel stability in bed load-dominated streams with nonerodible banks: Inferences from experiments in a sinuous flume

Experimental and computational evidence shows that bed state adjustments can accommodate a twofold to fourfold change in sediment supply without otherwise affecting the morphology of a sinuous gravel bed stream channel with nonerodible banks. In contrast, previously published experiments of the same kind but with erodible channel banks suggest that changes in sediment supply are taken up almost exclusively by changes in channel sinuosity and hence the reach-average water surface gradient. It appears that stream channel response to changes in sediment supply is strongly conditioned by the nature of the stream boundary, and that determines which of several potential adjustments are possible.