Fig. 4
From: Estimating WUI exposure probability to a nearby wildfire
An illustration of the “funnel” focal analysis area. A funnel is created with its central axis aligned with the shortest distance line connecting a WUI and a fire perimeter; each funnel has a fixed 90-degree opening angle. The funnel “leak ratio” is calculated as the length of the funnel edge not “shielded” by any completed firelines divided by the total length of the funnel edge along the wider side