Phoenix debris-flow hazard assessment: House location matters

Matthew Moore, Gregory Kraetz, Ronald Dorn

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Three catchments that debouch into Phoenix housing developments from the Ma Ha Tuak Range, South Mountain show a consistent pattern of declines in the magnitude of debris flows over time. We used a mix of field and geospatial methods to estimate volume, and the varnish microlamination technique to estimate minimum ages of debris deposits. Estimates of debris-flow volumes show a drop of more than two orders of magnitude from latest Pleistocene to 20th century or Little Ice Age. Debris-flow run-out lengths also shortened tremendously, with the most recent events stopping inside incised channels. In contrast, a catchment above houses in the Gila Range, South Mountain, where houses were built very close to the debris-flow source area, reveals an increase in debris-flow magnitude over time. These contrasting findings emphasize the importance of the location of home sites with respect to the debris-flow system in the type of small desert mountain catchments that interface with the sprawling urbanism found in Southwestern USA deserts.

Original languageEnglish (US)
Pages (from-to)491-513
Number of pages23
JournalPhysical Geography
Volume33
Issue number6
DOIs
StatePublished - Nov 1 2012

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Keywords

  • Arizona
  • Phoenix
  • debris flow
  • hazard assessment
  • rock varnish microlamination

ASJC Scopus subject areas

  • Environmental Science(all)
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Earth and Planetary Sciences(all)

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