Field-based generic empirical flame length-fireline intensity relationships for wildland surface fires
Document Type: Journal Article
Author(s): Carlos G. Rossa; David A. Davim; Ângelo Sil; Paulo M. Fernandes
Publication Year: 2024

Cataloging Information

  • combustion metrics
  • fire management
  • fireline intensity
  • flame length
  • forests
  • fuel metrics
  • grasslands
  • head fire
  • shrublands
  • surface area-to-mass ratio
  • surface fires
Record Maintained By:
Record Last Modified: February 1, 2024
FRAMES Record Number: 69047


Background: Fireline intensity (If) quantifies the power of the fireline and is used for various purposes. If and flame length (Lf) are relatable to each other using an empirical power function, which has been considered fuel-specific.

Aims: The aim of this study was to develop generic Lf − If relationships based on a robust set of field head fires from the literature (n = 797) conducted worldwide in forest, shrubland and grassland.

Methods: Lf was determined from the base of the fuel bed for comparability across fires in different fuel heights, and the effect of vegetation type was examined.

Key results: Although If could be approximately described using the same function in forest and shrubland, fires in grassland required different fitted coefficients; we speculate that fuel particles’ surface area-to-mass ratio is the main fuel metric influencing flame structure.

Conclusions: Fuel-generic relationships for If are reasonably accurate and encompass the high end of surface fire If. Previous studies suggested their unviability, most likely because of limitations in the number of observations and data ranges, difficulty in objectively measuring Lf and variation in Lf definition.

Implications: The generic relationships presented in this work will be of interest for research and management purposes when specific models for If are non-existent.

Online Link(s):
Rossa, Carlos G.; Davim, David A.; Sil, Ângelo; Fernandes, Paulo M. 2024. Field-based generic empirical flame length-fireline intensity relationships for wildland surface fires. International Journal of Wildland Fire 33:WF23127.