Abstract
The wildland-urban interface (WUI) is one of the fastest growing land-use types in the United States resulting in increased populations directly vulnerable to wildfire hazards. One way to mitigate fire danger near the WUI is through adjacent fuel reduction treatments. While there is a national priority to reduce fire risk through fuel treatments, the efficacy of such treatments to mitigate fire behavior in a changed climate is unknown. We selected four fuel treatments in southern California intercepted by wildfires within the last decade to evaluate fuel treatment effectiveness under future conditions. We used FlamMap to conduct a change analysis of flame length, fire line intensity, max spot distance, and crown fire activity using 97th percentile weather and fuel moisture representative of historical and projected mid-21st century conditions. We found little change in flame length, fire line intensity, max spot distance, and crown fire activity within the fuel treatment under future conditions. However, increased fire behavior activity 1-2 kilometers from fuel treatments under future climatic conditions could impact the fuel treatment effectiveness. These results have important implications to increase cost-effectiveness of long-term fuel treatment programs by providing suggestions on where to focus on strategic areas that require further reduction of fuels to allow for safe fire management operations, protection of property, life, and egress.