EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Quasi-universal relationship for alluvial river long-profile evolution

Andrew Wickert1,2 and B. Nilay İşcen1,2
Andrew Wickert and B. Nilay İşcen
  • 1University of Minnesota, Saint Anthony Falls Laboratory, Minneapolis, United States of America (
  • 2University of Minnesota, Department of Earth & Environmental Sciences, Minneapolis, United States of America (

Alluvial rivers aggrade and incise by moving sediment while simultaneously evolving their hydraulic geometries. For both gravel- and sand-bed rivers, stress-based criteria for equilibrium channel width in turn maintain a constant bed shear stress and therefore linearize the sediment-transport response to changing river discharge. Here we demonstrate that realistic sediment-transport and width-closure relationships yield a stream-power form for sediment discharge. Differentiating this in space (i.e., taking the divergence) yields a slightly nonlinear diffusion equation that describes long-profile evolution. This simple equation-coupling work suggests that a single equation may suffice to describe river long-profile evolution from the bedrock--alluvial transition to the point at which backwater effects become significant.

How to cite: Wickert, A. and İşcen, B. N.: Quasi-universal relationship for alluvial river long-profile evolution, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10729,, 2022.