Spatial Metrics of Fire Geometry and Their Relationship to Fire Areal Growth

The fire behavior triangle includes fuels, weather, and terrain. While these drivers determine rate of spread and intensity, they are not adequate for determining potential area growth on an existing fire. That depends on the overall geometry of the fire perimeter, and how it relates to areas of active burning at any given time. A fire that is only active in the interior, far from the burned perimeter, is less likely to grow significantly than a fire burning vigorously on the downwind edge. We examine a suite of metrics that quantify the spatial relationships among fire perimeter, active burning areas, and areas of scattered heat. We combine these with data on fuels, weather, and terrain to identify which spatial metrics provide the most power to predict how and where a fire will grow. We present results of a preliminary test using the 2020 Pine Gulch fire from 2020. Data sets examined include NAM 12 km weather forecasts, LANDFIRE terrain and fuels (BEHAVE fuel models), GOES-16 and VIIRS satellite detections.