The rainfall intensity-duration control of debris flows after wildfire
Increased wildfire activity in the western United States has exposed regional gaps in our understanding of postfire debris-flow generation. To address this problem, we characterized flows in an unstudied area to test the rainfall intensity-duration control of the hazard. Our rainfall measurements and field observations from the northern Sierra Nevada (California, USA) show that debris flows resulted from a short burst rainfall during a low-accumulation storm. In contrast, a much higher accumulation storm (∼10 times more rainfall) with lower short-duration rainfall rates only produced low-hazard flooding. We conclude that total storm rainfall is not an ideal metric for identifying the rainfall conditions that initiate runoff-generated debris flows in the first year after wildfire. Rather, a focus on short-duration (<1 hr), high-intensity rainfall that can occur during localized thunderstorms, or bands of intense rainfall during prolonged rainstorms, is more beneficial for the purposes of hazard assessment and warning.
Citation Information
| Publication Year | 2023 |
|---|---|
| Title | The rainfall intensity-duration control of debris flows after wildfire |
| DOI | 10.1029/2023GL103645 |
| Authors | Matthew A. Thomas, Donald N. Lindsay, David B. Cavagnaro, Jason W. Kean, Scott W. McCoy, Andrew Paul Graber |
| Publication Type | Article |
| Publication Subtype | Journal Article |
| Series Title | Geophysical Research Letters |
| Index ID | 70243884 |
| Record Source | USGS Publications Warehouse |
| USGS Organization | Geologic Hazards Science Center |
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Field-verified inventory of postfire debris flows for the 2021 Dixie Fire following a 23-25 October 2021 atmospheric river storm and 12 June 2022 thunderstorm
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Field-verified inventory of postfire debris flows for the 2021 Dixie Fire following a 23-25 October 2021 atmospheric river storm and 12 June 2022 thunderstorm
Summary This data release is a field-verified inventory of postfire debris flows for the 2021 Dixie Fire following a 23-25 October 2021 atmospheric river storm and 12 June 2022 thunderstorm. The “README.txt” file describes the fields for the “Inventory.csv” file. The “Chambers” and “Chips” rain gage data referenced in the inventory are included as: “Chambers-Oct2021-Storm.csv”, “Chambers-Jun2022-S - Connect