Cover effect in bedrock abrasion: A new derivation and its implications for the modeling of bedrock channel morphology

Controls on the channel width of rivers: Implications for modeling fluvial incision of bedrock

On the basis of the Manning equation and basic mass conservation principles, we derive an expression for scaling the steadystate width (W) of river channels as a function of discharge (Q), channel slope (S), roughness (n), and width-to-depth ratio (!): W " [!(! # 2)2/3]3/8Q3/8S$3/16n3/8. We propose that channel width-todepth ratio, in addition to roughness, is a function of the material in whic...

The Role of Sediment in Controlling Steady-State Bedrock Channel Slope: Implications of the Saltation-Abrasion Incision Model

Evaluating the controls of shear stress, sediment supply, alluvial cover, and channel morphology on experimental bedrock incision rate

[1] We explored the dependence of experimental bedrock erosion rate on shear stress, bed load sediment flux, alluvial bed cover, and evolving channel morphology. We isolated these variables experimentally by systematically varying gravel sediment flux Qs and water discharge Qw in a laboratory flume, gradually abrading weak concrete “bedrock.” All else held constant, we found that (1) erosion ra...

Controls and limits on bedrock channel geometry

[1] Data on channel geometry in naturally incising bedrock rivers reveal variable relationships between channel width, slope, and erosion rate. To explain the range of relationships between these parameters, we propose an optimized channel geometry model. The model reproduces previous theoretical and numerical modeling scaling relationships; however, to explain the field data, the model must in...

Transport slopes, sediment cover, and bedrock channel incision in the Henry Mountains, Utah

[1] Field data from channels in the Henry Mountains of Utah demonstrate that abundant coarse sediment can inhibit fluvial incision into bedrock by armoring channel beds (the cover effect). We compare several small channels that share tributary junctions and have incised into the same sedimentary bedrock unit (Navajo Sandstone) but contain differing amounts of coarse diorite clasts owing to the ...