Pre-fire assessment of post-fire debris flow hazards in the Santa Fe Municipal Watershed

International Journal of Wildland Fire
By: , and 

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Abstract

Background

Wildfires are increasing in size and severity due to climate change combined with overstocked forests. Fire increases the likelihood of debris flows, posing significant threats to life, property, and water supplies.

Aims

We conducted a debris-flow hazard assessment of the Santa Fe Municipal Watershed (SFMW) to answer two questions: (1) where are debris flows most likely to occur; and (2) how much debris might they produce? We also document the influence of fuel treatments on fire severity and debris flows.

Methods

We modelled post-fire debris-flow likelihood and volume in 103 sub-basins for 2-year, 5-year, and Probable Maximum Precipitation rainfalls following modelled low-, moderate-, and high-severity wildfires.

Key results

Post-fire debris-flow likelihoods were >90% in all but the lowest fire and rain scenarios. Sub-basins with fuel treatments had the lowest burn severities, debris-flow likelihoods, and sediment volumes, but treatment effects decreased with increased fire severity and rain intensity.

Conclusions

Post-fire debris flows with varying debris volumes are likely to occur following wildfire in the SFMW, but fuel treatments can reduce likelihood and volume.

Implications

Future post-fire debris flows will continue to threaten water supplies, but fuel reduction treatments and debris-flow mitigation provide opportunities to minimise effects.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Pre-fire assessment of post-fire debris flow hazards in the Santa Fe Municipal Watershed
Series title International Journal of Wildland Fire
DOI 10.1071/WF23065
Volume 33
Year Published 2024
Language English
Publisher CSIRO Publishing
Contributing office(s) Fort Collins Science Center
Description WF23065, 14 p.
Country United States
State New Mexico
Other Geospatial Santa Fe Municipal Watershed
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