Flame depth

n. The distance between the leading edge of the fire and the trailing edge.  


  • Discussion


The challenge when observing flame depth is defining the trailing edge of the fire. One proposed definition of the trailing edge is the point at which 90 percent of the available fine fuel has been consumed.  Flame depth is also defined as the product of rate of spread and flame residence time.  In the case of laboratory and field fires, flame depth can be determined either from rate of spread and residence time measurements or from direct measurement.  See Anderson and others (2006) for further discussion.


  • Units


    Preferred units for flame depth are m in technical reports and papers. Fire Management in the United States still uses the English units ft. See the following flame depth  units conversion table for conversion factors.


  • See Also

  • References

    • Anderson, W.; Pastor, E.; Butler, B.; Catchpole, E.; Dupuy, J.; Fernades, P.; Guijarro., M.; Mendes-Lopes, J.; Ventura, J. 2006. Evaluating models to estimate flame characteristics for free-burning fires using laboratory and field data: Proceedings 5th Intl. Conf. on For. Fire Res., Viegas, D.X., ed. 2006 November 27-30; Figueira daFoz, Portugal, University of Coimbra.  In: Elsevier, Forest Ecology and Management 234 Supplement 1 (2006).


  • Notes

    • Author 

      Bret Butler, Mechanical Engineer

      Rocky Mountain Research Station