Grieve, Stuart; Mudd, Simon; Hurst, Martin; Milodowski, David. (2016). A nondimensional relief framework: data, [dataset]. University of Edinburgh. School of GeoSciences.. https://doi.org/10.7488/ds/1366.
Considering the relationship between erosion rate and the relief structure of a landscape within a
nondimensional framework facilitates the comparison of landscapes undergoing forcing at a range of scales,
and allows broad-scale patterns of landscape evolution to be observed. We present software which automates
the extraction and processing of relevant topographic parameters to rapidly generate nondimensional erosion
rate and relief data for any landscape where high-resolution topographic data are available. Individual hillslopes
are identified using a connected-components technique which allows spatial averaging to be performed over
geomorphologically meaningful spatial units, without the need for manual identification of hillslopes.
The software is evaluated on four landscapes across the continental United States, three of which have been
studied previously using this technique. We show that it is possible to identify whether landscapes are in topographic
steady state. In locations such as Cascade Ridge, CA, a clear signal of an erosional gradient can be
observed. In the southern Appalachians, nondimensional erosion rate and relief data are interpreted as evidence
for a landscape decaying following uplift during the Miocene. An analysis of the sensitivity of this method to
free parameters used in the data smoothing routines is presented which allows users to make an informed choice
of parameters when interrogating new topographic data using this method. A method to constrain the critical
gradient of the nonlinear sediment flux law is also presented which provides an independent constraint on this
parameter for three of the four study landscapes.
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