Premium
Spectral Signature of Landscape Channelization
Author(s) -
Hooshyar Milad,
Katul Gabriel,
Porporato Amilcare
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl091015
Subject(s) - channelized , cascade , exponent , geology , fluvial , wavenumber , spectral shape analysis , power law , erosion , channel (broadcasting) , scaling , elevation (ballistics) , geometry , spectral line , physics , geomorphology , mathematics , optics , computer science , telecommunications , linguistics , chemistry , philosophy , statistics , chromatography , structural basin , astronomy , computer network
Channel networks increase in complexity as the importance of erosion grows compared to diffusion by soil creep, giving rise to a channelization cascade. Simulations, laboratory experiments, and data from a natural landscape are used to uncover the signature of such a cascade in the wavenumber spectrum of elevation fluctuations. Power spectra at intermediate distances from the boundaries are characterized by a peak wavenumber that is related to the quasi‐cyclic valleys superimposed on a power‐law scaling with exponent ( α ) at smaller scales. Dimensional analysis and self‐similarity arguments show that α is uniquely linked to the power‐law relation (with exponent m ) between erosion potential and the specific drainage area via α = 2 m − 3. This finding connects the spectral behavior of erosional surfaces to the exponent m that distinguishes between the steep landscapes with debris‐flow‐dominated channels and relatively flat fluvial landscapes and directly controls the shape of the channel profile.