Bedrock channel morphology

Analyses of 41 bedrock channel reaches indicate quantifiable relationships between bedrock channel morphology and reach-scale hydraulic and substrate variables. Discriminant analysis was used to develop a discriminant criteri on based on reach-averaged channel gradient, substrate heterogeneity, and S elby rock-mass strength. This criterion correctly classified 70% of the obs ervations into one of five channel morphologic types. Channels formed at hi gher gradients have a morphology that effectively maximizes the erosional f orce, whereas a morphology that evenly distributes flow energy or dissipate s flow energy internally is associated with lower gradients. These results suggest that bedrock channel morphology, like alluvial channel morphology, reflects a quantifiable balance between hydraulic driving and substrate res isting forces.