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Fluvial Channel Branching Enforces Threshold Relief
Author(s) -
Cunningham Maxwell T.,
Kaplan Michael R.
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 - 10.1029/2020gl091464
Subject(s) - fluvial , geology , elevation (ballistics) , geomorphology , drainage basin , streams , channel (broadcasting) , hydrology (agriculture) , physical geography , geography , structural basin , cartography , geometry , geotechnical engineering , mathematics , engineering , electrical engineering , computer network , computer science
Relief within mountain belts appears to be limited to a threshold of 1,000–1,500 m. However, it remains unclear definitively where in the landscape this threshold is found. Here we use a new method of analysis, termed Progressive Hypsometry, to show that “threshold relief” is the typical relief of first‐order fluvial catchments. The method tracks changes in the elevation frequency distribution (hypsometry) across nested catchments of all sizes. We find that self‐similar nesting of fluvial catchments leads to quasi‐scale invariance in hypsometry, such that the relief between any catchment's modal and outlet elevation ( R Mo , mode relief) falls into three groups: the two lower associated with steep upland subcatchments ( R Mo = 250–1,000 m) and the other with fluvial catchments, which span orders of magnitude in area but maintain an R Mo of 1,000–1,500 m. We conclude that threshold relief is the maximum relief a first‐order fluvial catchment can develop without branching.