Consistency of scaling relations among bedrock and alluvial channels

Abstract

This paper presents field data on channel geometry and potential control variables from 47 field settings representing a diverse range of environments. These data are used to evaluate existing scaling relationships used in models of the evolution of bedrock channel geometry and to test the hypothesis that channel width (w) increases more slowly and depth (d) more rapidly in relation to discharge (Q) or drainage area (A) as substrate resistance increases. For this data set, w ∼ A0.3, w ∼ Q0.5, d ∼ A0.2, and d ∼ Q0.3. The w‐A and w‐Q relations are close to those found by previous investigators. The d‐A and d‐Q relations have not previously been reported for bedrock channels. Examination of trends within the data does not support the hypothesis and, instead, suggests that the erosional resistance of channel boundaries is not the primary control on scaling relations for channel geometry.