Hanging valleys in fluvial systems

Controls on occurrence and implications for landscape evolution

Cameron W. Wobus, Benjamin T. Crosby, Kelin Whipple

Research output: Contribution to journalArticle

105 Citations (Scopus)

Abstract

We document and characterize hanging valleys in a fluvially eroded landscape in eastern Taiwan. Our conceptual model for the initiation of hanging valleys builds on a recently proposed model of bedrock incision in which erosion actually becomes less efficient on very steep channel gradients. If a pulse of incision in the main stem outpaces the tributary response, the gradients at tributary mouths may therefore pass a threshold value beyond which erosional efficiency declines, giving rise to a mismatch between trunk and tributary erosion rates. This mismatch is expected at junctions with small tributaries, where a step function decrease in drainage area also leads to sharp contrasts in water and sediment flux between trunk and tributary channels. The occurrence of hanging valleys in actively uplifting fluvial landscapes such as the Central Range of Taiwan suggests that the most common parameterizations of bedrock erosion, which typically assume a monotonic positive correlation between channel gradient and incision rate, may be violated in very steep channels. In addition, hanging valleys could greatly increase the response time of landscapes to tectonic perturbations since catchments above these tributary mouths will be insulated from these perturbations until a new suite of processes (e.g., weathering and rock mass failure) wear through the hanging valley lip. The results of this study underscore the need for a more complete understanding of bedrock erosion processes and the incorporation of process transitions and threshold conditions into landscape evolution models.

Original languageEnglish (US)
Article numberF02017
JournalJournal of Geophysical Research: Earth Surface
Volume111
Issue number2
DOIs
StatePublished - Jun 24 2006
Externally publishedYes

Fingerprint

tributaries
landscape evolution
valleys
control system
Erosion
tributary
occurrences
Control systems
valley
erosion
bedrock
mouth
Taiwan
gradients
Tectonics
Weathering
Parameterization
perturbation
Catchments
Drainage

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

Cite this

Hanging valleys in fluvial systems : Controls on occurrence and implications for landscape evolution. / Wobus, Cameron W.; Crosby, Benjamin T.; Whipple, Kelin.

In: Journal of Geophysical Research: Earth Surface, Vol. 111, No. 2, F02017, 24.06.2006.

Research output: Contribution to journalArticle

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