Derivation of the 1- and 10-hour timelag fuel moisture calculations for fire-danger rating
Document Type: Report
Author(s): Michael A. Fosberg; John E. Deeming
Publication Year: 1971

Cataloging Information

  • climatology
  • fine fuels
  • fire danger rating
  • fire management planning
  • fire models
  • fire weather
  • forest management
  • fuel management
  • fuel models
  • fuel moisture
  • fuel types
  • fuelwood
  • humidity
  • mathematical models
  • moisture
  • NFDRS - National Fire Danger Rating System
  • Pinus ponderosa
  • radiation
  • rate of spread
  • relative humidity
  • temperature
  • timelag
  • weather observations
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 14186
Tall Timbers Record Number: 499
TTRS Location Status: In-file
TTRS Abstract Status: Okay, Fair use, 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.


Procedures for calculating the moisture contents of 1- and 10-hour timelag fuels have been developed based on theoretical calculations of the rate of moisture transport in wood. The 1 -hour timelag calculation is superior to fine fuel moisture calculations developed previously because there is no regional bias, making it valid over a wider range of conditions, and because it separates out the effects of the environmental factors of temperature, humidity, and solar radiation. The 10-hour timelag calculation produced values reasonably consistent with observations obtained from 1/2-inch ponderosa pine fuel sticks exposed under field conditions.

Online Link(s):
Fosberg, Michael A.; Deeming, John E. 1971. Derivation of the 1- and 10-hour timelag fuel moisture calculations for fire-danger rating. Research Note RM-RN-207. Fort Collins, CO: USDA Forest Service, Rocky Mountain Forest and Range Experiment Station. 8 p.