Details

Autor(en) / Beteiligte

• Hobley, Daniel E. J.
• Sinclair, Hugh D.
• Mudd, Simon M.
• Cowie, Patience A.

Titel

Field calibration of sediment flux dependent river incision

Ist Teil von

• Journal of Geophysical Research, 2011-12, Vol.116 (F4), p.n/a, Article F04017

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2011

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Bed erosion and sediment transport are ubiquitous and linked processes in rivers. Erosion can either be modeled as a “detachment limited” function of the shear stress exerted by the flow on the bed, or as a “transport limited” function of the sediment flux capacity of the flow. These two models predict similar channel profiles when erosion rates are constant in space in time, but starkly contrasting behavior in transient settings. Traditionally detachment limited models have been used for bedrock rivers, whereas transport limited models have been used in alluvial settings. In this study we demonstrate that rivers incising into a substrate of loose, but very poorly sorted relict glacial sediment behave in a detachment limited manner. We then develop a methodology by which to both test the appropriate incision model and constrain its form. Specifically we are able to tightly constrain how incision rates vary as a function of the ratio between sediment flux and sediment transport capacity in three rivers responding to deglaciation in the Ladakh Himalaya, northwest India. This represents the first field test of the so‐called “tools and cover” effect along individual rivers. Key Points Shear stress and incision distributions can discriminate between erosion models Both the tools and cover effects are active in incision in this field area We describe the forms of the sediment flux dependent functions for this site