Conversion of Williams' severity rating for use with the fire weather index
Document Type: Book
Author(s): C. E. Van Wagner
Publication Year: 1970

Cataloging Information

  • Canada
  • fire danger rating
  • fire intensity
  • fire management
  • season of fire
  • statistical analysis
  • wildfires
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 39070
Tall Timbers Record Number: 13697
TTRS Location Status: In-file
TTRS Call Number: CAN DOCS Information Report PS-X-21 DDW
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.


From the text: 'In 1959 Williams published a method of calculating the fire season severity rating, an integrated measure of fire weather over the whole season. Being based solely on the daily fire danger index (1956 type), it could be used as an objective yardstick for comparing fire weather from year to year or from site to site within any region using the same danger tables. The seasonal severity rating (SSR) is essentially a weighted average of the daily danger indexes in the old 16-point scale. The weighting factors were developed from 2-minute test fires in jack pine, using a combination of fire perimeter and drought index to represent severity Thus each day can be assumed to have its individual daily severity rating (DSR), and a severity rating can be calculated for any desired period such as a week or a month.'

Van Wagner, C. E. 1970. Conversion of Williams' severity rating for use with the fire weather index. Information Report PS-X-21. Chalk River, Ontario, Petawawa Forest Experiment Station.