loading page

Topographic roughness on forested hillslopes: a theoretical approach for quantifying hillslope sediment flux from tree throw
  • +1
  • Tyler H Doane,
  • Douglas Arthur Edmonds,
  • Brian J Yanites,
  • Quinn W Lewis
Tyler H Doane
Indiana University-Bloomington

Corresponding Author:doanet@iu.edu

Author Profile
Douglas Arthur Edmonds
Indiana University
Author Profile
Brian J Yanites
Indiana University
Author Profile
Quinn W Lewis
University of Waterloo
Author Profile


Tree uprooting is an observable and consequential process that suddenly moves soil downslope, inverts the soil column, and roughens the surface with pit-mound topography. Quantifying fluxes due to tree throw is complicated by its stochastic nature and estimation requires averaging over a large area or long time. Here, we develop theory that leads to a dimensionless metric directly measurable from high resolution topographic data. The theory explains the flux and topographic roughness as a function of tree throw production and decay rate by creep-like processes. We then form a dimensionless variable that is the ratio of fluxes due to three throw versus creep-like processes. Applying the theory to hillslopes in Southern Indiana, we find that tree throw accounts for 10 to 20\% of the hillslope sediment flux. The theoretical and observational findings provide a framework and important constraints on quantifying Critical Zone function from topographic parameters such as roughness.
28 Oct 2021Published in Geophysical Research Letters volume 48 issue 20. 10.1029/2021GL094987