Estimating wildland fire rate of spread in a spatially nonuniform environment
Document Type: Journal Article
Author(s): Francis M. Fujioka
Publication Year: 1985

Cataloging Information

  • fine fuels
  • fire control
  • fire danger rating
  • fire management
  • fire models
  • fire spread
  • fire weather
  • fuel types
  • harmonic mean
  • Jensen's inequality
  • rate of spread
  • surface area-to-volume ratio
  • topography
  • wilderness fire management
  • wildfires
Partner Site(s):
Record Maintained By:
Record Last Modified: January 7, 2019
FRAMES Record Number: 8148
Tall Timbers Record Number: 9272
TTRS Location Status: In-file
TTRS Call Number: Fire File DDW
TTRS Abstract Status: Fair use, Okay, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.


Estimating rate of fire spread is a key element in planning for effective fire control. Land managers use the Rothermel spread model, but the model assumptions are violated when fuel, weather, and topography are nonuniform. This paper compares three averaging techniques--arithmetic mean of spread rates, spread based on mean fuel conditions, and harmonic mean of spread rates--used to estimate the effective rate-of-spread in heterogeneous environments. For particular ranges of the independent variables of the spread model, there is a well-defined ordering of the averages-a consequence of the convexity of the spread function. The harmonic mean of spread rates along the burn path is offered as an appropriate estimator of fire spread rate in a nonuniform field.

Online Link(s):
Fujioka, Francis M. 1985. Estimating wildland fire rate of spread in a spatially non-uniform environment. Forest Science 31(1):21-29.