JGR_2021_4_lupin.pdf (1.42 MB)
Evaluating landscape complexity and the contribution of non‐locality to geomorphometry
journal contribution
posted on 2021-03-30, 10:37 authored by Chris KeylockChris Keylock, A Singh, P Passalacqua, E Foufoula‐GeorgiouA long-standing question in geomorphology concerns the extent that
statistical models of terrain elevations have adequate characteristics with
respect to the known scaling properties of landscapes. In previous work, it
has been challenging to ascribe statistical significance to metrics adopted
to measure landscape properties. In this paper, we use a recently developed surrogate data algorithm to generate synthetic surfaces with identical elevation values to the source dataset, while also preserving the value
of the H¨older exponent at any point (the underpinning characteristic of
a multifractal surface). Our primary source data are from a laboratory
experiment on landscape evolution. This allows us to examine how the
statistical properties of the surfaces evolve through time and the extent
to which they depart from the simple (multi)fractal formalisms. We show
that there is a strong departure that is driven by the diffusive processes in
operation. The number of sub-basins of a given channel order (for orders
sufficiently small relative to the basin order) exhibit a clear increase in
complexity after a steady-state for sediment flux is established. We also
study elevation data from Florida and Washington State where the relative departure from simple multifractality is even more strongly expressed
but is similar for two very different locations. Our results show that at
the very least, the minimum complexity for a stochastic model for terrain statistics with appropriate geomorphic scalings needs to incorporate
a conditioning between the pointwise H¨older exponents and elevation.
Funding
Royal Academy of Engineering/Leverhulme Trust Senior Research Fellowship LTSRF1516-12-89
NSF (grants EAR-1811909 and ECCS-1839441)
History
School
- Architecture, Building and Civil Engineering
Published in
Journal of Geophysical Research: Earth SurfaceVolume
126Issue
4Citation
Keylock, C. ... et al. ,(2021), Evaluating landscape complexity and the contribution of non‐locality to geomorphometry, Journal of Geophysical Research: Earth Surface, 126, 4, DOI: 10.1029/2020jf005765Publisher
American Geophysical Union (AGU)Version
- AM (Accepted Manuscript)
Rights holder
© American Geophysical UnionPublisher statement
An edited version of this paper was published by AGU. Copyright (year) American Geophysical Union. Accepted for publication in Journal of Geophysical Research: Earth Surface. Copyright (year) American Geophysical Union. To view the published open abstract, go to http://dx.doi.org and enter the DOI.Acceptance date
2021-03-14Publication date
2021-04-18Copyright date
2021ISSN
2169-9003eISSN
2169-9011Publisher version
Language
- en