Climate-Driven Variability in Runoff Erosion Encoded in Stream Network Geometry

TitleClimate-Driven Variability in Runoff Erosion Encoded in Stream Network Geometry
Publication TypeJournal Article
Year of Publication2021
AuthorsGetraer A, Maloof AC
JournalGeophys Res Lett
Volume48
Issue3
Paginatione2020GL091777
Date Published2021/02/16
ISBN Number0094-8276
Other Numbers72Maloof
Keywordsclimate, geomorphology, landscape evolution, runoff erosion, stream geometry, stream network
Abstract

Abstract Climate signatures recorded in the geometry of branching streams provide insight into climate and landscape histories on Earth and other planetary bodies. Recent findings establish that branching angles are narrower and stream profiles are straighter in more arid climates. However, these two observations have been attributed to different mechanisms. Here we demonstrate that for US watersheds the difference in slope between confluent streams increases with humidity, and streams with a greater difference in slope tend to branch at wider angles. Our observations suggest a branching angle endmember of 90° when stream slopes are most different. Using a simple model of runoff erosion, we show how this variation in relative stream slopes can be explained by a shift in streamflow accumulation across climate regimes. These findings connect previously observed climate signatures in branching angles and stream profiles, suggesting that both record the same control of aridity on surface flow.

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URLhttps://doi.org/10.1029/2020GL091777
DOI10.1029/2020GL091777
Short TitleGeophysical Research Letters