Developing and testing physically based triggering thresholds for runoff‐generated debris flows
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- More information: Publisher Index Page (via DOI)
- Data Release: USGS data release - Post-wildfire debris-flow monitoring data, Las Lomas, 2016 Fish Fire, Los Angeles County, California, November 2016 to February 2017
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Abstract
Runoff in steep channels is capable of transitioning into debris flows with hazardous implications for downstream communities and infrastructure, particularly in alpine landscapes with minimal vegetation and areas recently disturbed by wildfire. Here, we derive thresholds for the initiation of runoff‐generated debris flows based on critical values of dimensionless discharge and Shields stress. These thresholds are derived by using a numerical model to estimate the hydrodynamic conditions coinciding with the timing of debris flow activity in a recently burned basin. A benefit of hydrodynamic thresholds is that they can be used to assess debris flow likelihood based on measurable hydrologic and geomorphic parameters and therefore provide more universal criteria for quantifying the runoff‐to‐debris flow transition in landscape evolution studies and hazard assessments. We then demonstrate how hydrodynamic thresholds can be used to estimate rainfall intensity‐duration thresholds for runoff‐generated debris flows without the need for historic debris flow observations.
Study Area
Publication type | Article |
---|---|
Publication Subtype | Journal Article |
Title | Developing and testing physically based triggering thresholds for runoff‐generated debris flows |
Series title | Geophysical Research Letters |
DOI | 10.1029/2019GL083623 |
Volume | 46 |
Issue | 15 |
Year Published | 2019 |
Language | English |
Publisher | American Geophysical Union |
Contributing office(s) | Geologic Hazards Science Center |
Description | 10 p. |
First page | 8830 |
Last page | 8839 |
Country | United States |
State | California |
Other Geospatial | San Gabriel Mountains |
Google Analytic Metrics | Metrics page |