From: VONN Teresa
Sent: Wednesday, July 01, 2009
10:41 AM
To: LITTLE Jim
Subject: RE: Significant Fire
Potential Map description
The Oregon Department of
Forestry (ODF) Significant Fire Potential map is the visual display of the
results of a series of analysis of historic weather and fires that typically
taxed or exceeded initial attack capabilities.
The map is not a adjective or
Fire Danger map. The Fire Danger for each Unit or District is determined locally
by Fire Managers and is displayed on their individual website such as:
The map is not a regulated use
or Industrial Fire Precaution Level Map.
The Forest Closure information
is located at the following links:
The ODF Fire Environment Working Group (FEWG)
was established in 2005 with the purpose of:
providing
information concerning fire intelligence and the fire environment for fire
managers and firefighters around the State. This task was to be accomplished
through training, guidance, and tool development in the areas of fire behavior,
fire danger assessments, and fire planning. The tools developed would be
aids to safely, effectively, and efficiently accomplish fire management
objectives. One of the focuses of the FEWG is to establish minimum baseline
objectives related to understanding and implementing the National Fire Danger
Rating System (NFDRS) and participation in fire planning opportunities such as
Fire Danger Operating Plans. The goal is to move the department towards more
effectively utilizing nationally recognized interagency tools and
information that is currently available and that are being developed.
To that end a series of Fire
Danger Technical visits began in 2006 that brought members of the FEWG Steering
Committee to locations across the state to provide peer review of pocket cards
and the analysis used to produce those cards. A review of the method of
communicating NFDRS indices to firefighters and mangers was reviewed and
documented. The fire danger analysis which establishes fire business thresholds
and is used to produce pocket cards is done locally, with a peer review by other
fire danger technical specialists to ensure that the breakpoints have been
developed in a valid and consistent manner across the state. A valid and
consistent approach then makes this NFDRS analysis a useful tool that helps
local managers make informed fire danger management decisions and also enhances
fire fighter safety.
Pocket Cards are
available for ODF protected lands at the following link:
Further fire business analysis
resulted in the ODF, NFDRS based Significant Fire Potential analysis. The
Significant Fire Potential analysis is based upon historical fire occurrence and
weather using FireFamily Plus, which provides a nationally recognized method and
consistent approach. The Significant Fire Potential map became a by-product of
these assistance visits. It provides a more useful visual tool than what
previously had existed to make as assessment of the potential for significant
fires across the state. As Districts established their fire business threshold
breakpoints for low, medium, high, very high, and extremely high potential for
significant fires to occur, it just seemed to make sense to display them on a
map. The map is one of many tools for local Fire Managers to utilize when making
decisions including changing fire danger restrictions, or forest closures.
NFDRS has a long history in the US and Canada.
In 1954 there were eight different fire danger rating systems used throughout
the country among various fire fighting agencies. Through agreements and
compacts work on a national system was begun in 1959 and by 1961 an outline was
established. In 1972 the system became operational nationwide. Until 1994 ODF
was utilizing its own unique Fire Danger Rating System; after 1994 ODF
transitioned to NFDRS.
The NFDRS is a set of computer
programs and algorithms that allow land management agencies to estimate today's
or tomorrow's fire danger for a given rating area. Calculations of fire danger
are based on fuels, topography and weather. NFDRS outputs give relative ratings
of the potential growth and behavior for a general area. It must be stressed
that this is not a fire behavior prediction system. NFDRS is a relative
system and is not intended to predict fire behavior but is intended to allow for
a statistical analysis of historical fire and weather data to determine various
percentiles in the distribution of historic data that will then serve as
breakpoints for fire management decisions.
Teresa Vonn
Fire Program
Analyst
Oregon
Department of Forestry
tvonn@odf.state.or.us