n. A segment of fire perimeter oriented opposite the direction of maximum spread.
The rate of spread and fireline intensity of a backing fire are usually low. Rothermel's (1972) surface fire spread model predicts fire behavior at the head of the fire. Two methods are available for predicting the behavior of a backing fire: (1) the no-wind/no-slope spread rate can be used to represent a backing fire, or (2) the elliptical dimensions of the fire can be used to estimate the behavior of a backing fire. Use of elliptical dimensions of a fire allows the simulation of fire behavior for a segment of fire perimeter oriented in any direction with respect to the direction of maximum spread.
A backfire is an advanced firefighting tactic that is not related to backing fire.