Calculating and interpreting forest fire intensities

TLDR

Frontal fire intensity, measured in kilowatts per metre, quantifies the energy output per unit length of a fire front as the product of net heat of combustion, fuel consumption, and spread rate. This metric offers a quantitative basis for describing fire behavior and assessing its impact on forest ecosystems.

Abstract

Frontal fire intensity is a valid measure of forest fire behavior that is solely a physical attribute of the fire itself. It is defined as the energy output rate per unit length of fire front and is directly related to flame size. Numerically, it is equal to the product of net heat of combustion, quantity of fuel consumed in the active combustion zone, and a spreading fire's linear rate of advance. The recommended International System (SI) units are kilowatts per metre. This concept of fire intensity provides a quantitative basis for fire description useful in evaluating the impact of fire on forest ecosystems.