Climate dictates magnitude of asymmetry in soil depth and hillslope gradient

Geophysical Research Letters
By: , and 

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Abstract

Hillslope asymmetry is often attributed to differential eco‐hydro‐geomorphic processes resulting from aspect‐related differences in insolation. At midlatitudes, polar facing hillslopes are steeper, wetter, have denser vegetation, and deeper soils than their equatorial facing counterparts. We propose that at regional scales, the magnitude in insolation‐driven hillslope asymmetry is sensitive to variations in climate, and investigate the fire‐prone landscapes in southeastern Australia to evaluate this hypothesis. Patterns of asymmetry in soil depth and landform were quantified using soil depth measurements and topographic analysis across a contemporary rainfall gradient. Results show that polar facing hillslopes are steeper, and have greater soil depth, than equatorial facing slopes. Furthermore, we show that the magnitude of this asymmetry varies systematically with aridity index, with a maximum at the transition between water and energy limitation, suggesting a possible long‐term role of climate in hillslope development.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Climate dictates magnitude of asymmetry in soil depth and hillslope gradient
Series title Geophysical Research Letters
DOI 10.1029/2018GL077629
Volume 45
Issue 13
Year Published 2018
Language English
Publisher AGU
Contributing office(s) Geologic Hazards Science Center
Description 9 p.
First page 6514
Last page 6522