APPLICATION OF A DEBRIS FLOW POTENTIAL MODEL ON THE 2008 PANTHER FIRE ON THE KLAMATH NATIONAL FOREST, NORTHERN CALIFORNIA

Debris flows are a destructive force in the steep landscape of the Klamath Mountains in Northern California. Wildfires exacerbate the debris flow potential and volume by altering the characteristics of the hillslopes. These wildfire related debris flows can damage downstream facilities and block major roadways. The US Forest Service responds to fire events by deploying a Burned Area Emergency Response (BAER) Team to rapidly assess the threats to life and property. The assessment often includes an evaluation of debris flow potential and recommends mitigations. The mitigation measures for debris flows can be costly and it is imperative to have a tool to allow for the immediate prioritization of debris flow mitigation in burned areas. An existing post-fire debris flow model, calibrated for the Intermountain West, was applied to the 2008 Panther Fire on the Klamath National Forest in to evaluate its utility for BAER assessments in Northern California. The model predicts the probability of a debris flow event based on parameters easily obtained in existing spatial data. These include fire severity, slope, rainfall intensity, and soil characteristics. Two small debris flows were documented in the fire area due to a storm event in May 2009. The outcome of the model was compared to the field data collected to determine its applicability to fires on the Klamath National Forest. The debris flows occurred in the drainage basins with the highest debris flow probability indicating that, at the very least, the model could be used to relatively prioritize BAER restoration activities in the fire perimeter.