Unveiling the Dynamics of Human Mobility in Response to Wildfire-Induced Air Quality Degradation: An Examination of the 2019 Kincade Fire

Abstract

Rising wildfire frequency and intensity are exacerbating air pollution, significantly impacting human mobility, particularly among vulnerable populations like low-income, elderly, and minority groups. This study, set in Sonoma County, California during the 2019 Kincade Fire, examines how particulate matter 2.5 (PM2.5) affects mobility patterns in communities not under direct evacuation orders. Analyzing daily home-dwell time, travel distance, and resident outflow, we note variations in how different groups respond to changing PM2.5 levels. Our findings reveal a direct relationship between PM2.5 concentration and mobility changes: higher PM2.5 levels are linked to increased travel distances and reduced home-dwell times, suggesting an adaptive response to air quality degradation. A notable decrease in weekend outflows indicates heightened air quality concerns affecting mobility. Through counterfactual analysis, we isolate the effects of PM2.5 on mobility patterns, and the results suggest that deteriorating air quality correlates with reduced outflow ratios. Our findings emphasize the need for targeted policy interventions to help vulnerable populations enhance their resilience to air quality deterioration during such events.