Landscape-Level Measurements of and Controls on Wildfire Spread Rates

San Diego State University Foundation, San Diego CA

Investigators

Abstract

NATIONAL SCIENCE FOUNDATION GEOGRAPHY SPATIAL SCIENCES (GSS) PROGRAM ABSTRACT This research project will contribute new knowledge regarding wildfires spread, the physical mechanisms through which they spread, and how wind, topography, and fuel properties affect their propagation. Observation and analyses of how fast a wildfire front travels is challenging because of the transient, hazardous nature of wildfires and the spatially heterogeneous conditions in which they occur. The project will enhance capabilities for inferring fire-spread rates and wind speeds by developing a new approach for delineating fire fronts and measuring their movements from precisely aligned airborne thermal infrared images. These measurements and analyses of fire-spread rates have not been possible at scales that are needed to understand fire behavior and its relationship to factors like fuel properties, topography, and wind. Outcomes from this research will support more sustainable fire practices. Measuring and generating knowledge about rates of and controls on wildfire spread will benefit the fire-science and fire-management communities as well as emergency response managers throughout the world. Wildfire-spread rates are key information requirements for fire suppression and evacuations. Their measurement and prediction pose a critical scientific challenge. Observing and analyzing how fast a wildfire front is traveling is challenging due to the transient, hazardous nature of wildfires and the spatially heterogeneous conditions in which they occur. To address these challenges, the investigators will use airborne thermal infrared imaging to acquire frequent and detailed tracking of moving flaming fronts for an area of chaparral vegetation in southern California. The flight lines will be aligned along the direction of the flaming front in the vicinity of the maximum spread zone. Frequent, sequential images captured along flight lines will enable wind speeds to be estimated through image flow analysis techniques. Segments of the fire line will be analyzed using spatial statistical and geovisualization methods to empirically establish the relationships between the rate of wildfire spread and characteristics or conditions of the vegetation fuels, terrain, and wind at the landscape scale. Project benefits to the broader community will include better tools to evaluate fire behavior and better estimates of the response of wildfires to fuel conditions and treatments.