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| Open-File Report 03–481    |

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## Emergency Assessment of Debris-Flow Hazards from Basins Burned by the Piru, Simi,  and Verdale Fires of 2003, Southern California

#### By Susan H. Cannon, Joseph E. Gartner, Michael G. Rupert, and John A. Michael

| These maps present preliminary assessments of the probability of debris-flow        activity and estimates of peak discharges that can potentially be generated        by debris flows issuing from basins burned by the Piru, Simi and Verdale        Fires of October 2003 in southern California in response to the 25-year,        10-year, and 2-year 1-hour rain storms. The probability maps are based        on the application of a logistic multiple regression model that describes        the percent chance of debris-flow production from an individual basin        as a function of burned extent, soil properties, basin gradients and        storm rainfall. The peak discharge maps are based on application of a        multiple-regression model that can be used to estimate debris-flow peak        discharge at a basin outlet as a function of basin gradient, burn extent,        and storm rainfall.

**Version 1.0**
Posted 2003
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| U.S. Department of the Interior | U.S. Geological Survey      URL: https://pubsdata.usgs.gov/pubs/of/2003/ofr-03-481/Questions or Assistance: USGS Web ContactPage Last Modified: Sat Jan 12 23:26 EDT 2013 |  |

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