Charles B. Yackulic Jaime Kostelnik Andrew R. Bock Robert E. Zuellig Daren M. Carlisle James J. Roberts Kevin B. Rogers Seth M. Munson Adam Gerhard Wells 2024 <p><strong>Background</strong></p><p>Colorado River Cutthroat Trout (CRCT;&nbsp;<i>Oncorhynchus clarkii pleuriticus</i>) conservation populations may be at risk from wildfire and post-fire debris flows hazards.</p><p><strong>Aim</strong></p><p>To predict burn severity and potential post-fire debris flow hazard classifications to CRCT conservation populations before wildfires occur.</p><p><strong>Methods</strong></p><p>We used remote sensing, spatial analyses, and machine learning to model 28 wildfire incidents (2016–2020) and spatially predict burn severity from pre-wildfire environmental factors to evaluate the likelihood (%) and volume (m³) hazard classification of post-fire debris flow.</p><p><strong>Key results</strong></p><p>Burn severity was best predicted by fuels, followed by topography, physical ecosystem conditions, and weather (mean adjusted&nbsp;<i>R</i>²&nbsp;=&nbsp;0.54). Predictions of high or moderate burn severity covered 1.1 (15% of study area) and 1.5 (19% of study area) million ha, respectively, and varied by watershed. Combined high or moderate debris flow hazard classification included 80% of stream reaches with conservation populations and 97% of conservation population point nodes.</p><p><strong>Conclusions</strong></p><p>Predicted burn severity and potential post-fire debris flow indicated moderate to high hazard for CRCT conservation populations native to the Green and Yampa rivers of the Upper Colorado River Basin.</p><p><strong>Implications</strong></p><p>Future management actions can incorporate predicted burn severity and potential post-fire debris flow to mitigate impacts to CRCT and other at-risk resource values before a wildfire occurs.</p> application/pdf 10.1071/WF23199 en CSIRO Publishing Before the fire: Predicting burn severity and potential post-fire debris-flow hazards to Colorado River Cutthroat Trout (Oncorhynchus clarkii pleuriticus) conservation populations article