Distinguishing between debris flows and floods from field evidence in small watersheds
Fact Sheet
2004-3142
Links
- More information: USGS Index Page (html)
- Document: Report
- Download citation as: RIS | Dublin Core
Abstract
Post-flood indirect measurement techniques to back-calculate flood magnitude are not valid for debris flows, which commonly occur in small steep watersheds during intense rainstorms. This is because debris flows can move much faster than floods in steep channel reaches and much slower than floods in low-gradient reaches. In addition, debris-flow deposition may drastically alter channel geometry in reaches where slope-area surveys are applied. Because high-discharge flows are seldom witnessed and automated samplers are commonly plugged or destroyed, determination of flow type often must be made on the basis of field evidence preserved at the site.
Suggested Citation
Pierson, T.C., 2005, Distinguishing between debris flows and floods from field evidence in small watersheds: U.S. Geological Survey Fact Sheet 2004-3142, 4 p., https://doi.org/10.3133/fs20043142.
ISSN: 2327-6932 (online)
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Distinguishing between debris flows and floods from field evidence in small watersheds |
| Series title | Fact Sheet |
| Series number | 2004-3142 |
| DOI | 10.3133/fs20043142 |
| Year Published | 2005 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Contributing office(s) | Cascades Volcano Observatory, Volcano Hazards Program, Volcano Science Center |
| Description | 4 p. |