Debris flow initiation by runoff in a recently burned basin: Is grain-by-grain sediment bulking or en masse failure to blame?

Luke A. McGuire, Francis K. Rengers, Jason W. Kean, Dennis M. Staley

Research output: Contribution to journalArticlepeer-review

49 Scopus citations

Abstract

Postwildfire debris flows are frequently triggered by runoff following high-intensity rainfall, but the physical mechanisms by which water-dominated flows transition to debris flows are poorly understood relative to debris flow initiation from shallow landslides. In this study, we combined a numerical model with high-resolution hydrologic and geomorphic data sets to test two different hypotheses for debris flow initiation during a rainfall event that produced numerous debris flows within a recently burned drainage basin. Based on simulations, large volumes of sediment eroded from the hillslopes were redeposited within the channel network throughout the storm, leading to the initiation of numerous debris flows as a result of the mass failure of sediment dams that built up within the channel. More generally, results provide a quantitative framework for assessing the potential of runoff-generated debris flows based on sediment supply and hydrologic conditions.

Original languageEnglish (US)
Pages (from-to)7310-7319
Number of pages10
JournalGeophysical Research Letters
Volume44
Issue number14
DOIs
StatePublished - Jul 28 2017

Keywords

  • debris flow
  • model
  • runoff
  • sediment transport
  • wildfire

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

Fingerprint

Dive into the research topics of 'Debris flow initiation by runoff in a recently burned basin: Is grain-by-grain sediment bulking or en masse failure to blame?'. Together they form a unique fingerprint.

Cite this