EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Landscape and river self-organization limit the flux of fine particles

Colin Phillips1, Carlos Rogéliz2, Daniel Horton3, Jonathan Higgins4, and Aaron Packman1
Colin Phillips et al.
  • 1Northwestern University, McCormick School of Engineering, Civil and Environmental Engineering, evanston, United States of America (
  • 2Northern Andes and South Central America, The Nature Conservancy
  • 3Earth and Planetary Sciences, Northwestern University
  • 4Energy and Infrastructure, The Nature Conservancy

Fine particles in rivers comprise a substantial fraction (>50%) of the mass leaving a landscape, while at shorter timescales they represent significant carriers of nutrients and contaminants with the potential to both degrade and enhance aquatic habitats. Predicting fine particle dynamics within rivers remains challenging due to a complex relationship between sediment and water availability from the landscape. This inherent complexity results in watershed-specific understandings of suspended sediment dynamics, typically parameterized as empirical functions of catchment land use, geology, and climate. However, observations of significant fine particle storage within river corridors may indicate that the flux of suspended sediment depends on reach-scale hydraulics. To better understand these dynamics, we synthesized over 40 years of suspended sediment concentration (SSC), hydraulic geometry, river flow, and grainsize data collected by the US Geological Survey from hundreds of rivers spanning a large variety of environments across the continental United States. This data synthesis reveals a strong nonlinear trend between reach-scale hydraulics and the suspended sediment flux, with a secondary dependence on particle properties. The multi-site synthesis reveals that by normalizing the suspended sediment flux by the bankfull shear stress and flux results in a collapse of the observed data onto a single function that describes a self-organizing structure for suspended sediment transport in watersheds. This general relationship indicates strong support for the role of autogenic processes in setting the flux of fine particles and erosion rates of watersheds.

How to cite: Phillips, C., Rogéliz, C., Horton, D., Higgins, J., and Packman, A.: Landscape and river self-organization limit the flux of fine particles , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12885,, 2020.


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