High-Resolution Wildfire Evacuation Risk Assessment for Mitigation Implementation

California has experienced a growing number of wildfires that have overwhelmed community preparedness and evacuation plans. In partnership with the Marin Wildfire Prevention Authority (MWPA), we identified and aggregated risks associated with wildfire evacuations in Marin County, CA, to assist local officials with identifying and prioritizing areas of concern and relevant mitigation actions. We first performed a state-of-the-science literature review to understand the causes of civilian fatalities during wildfire evacuations and the associated risk factors. Risk factors are defined as conditions that hinder timely evacuation and the ability to arrive at a safe location. For example, risk factors include rapid fire movement, lack of vehicle access, failure to receive timely notifications, heavy traffic burdens, or low risk perception. We then reviewed, gathered, and aggregated relevant high-resolution spatial datasets from local agencies, including fire departments, emergency services, and county officials. Throughout the study, we engaged with a Technical Advisory Team (TAT) comprised of fire, transportation, and planning agency officials to ensure meaningful results and develop realistic actions. Insights from the literature review and TAT advisors were used to perform a suitability analysis on the available datasets. Our analysis provides a 5-m resolution current conditions assessment of evacuation difficulties associated with fire and fuels (vegetation), communication and human decision-making, and traffic flow. The high-resolution evacuation difficulty scores produced from this study can be used to identify (1) potential areas of high risk during an evacuation, and (2) mitigation strategies that are risk-factor specific. Local officials will use the compiled maps, evacuation difficulty assessments, and recommendations to inform mitigation projects, policies, and pilot studies that may improve evacuation outcomes. In this presentation, we will discuss lessons learned from our direct collaboration with local officials, key findings from the literature review, an overview of the methods used to generate evacuation difficulty scores, key examples, and implications for mitigative actions.