What is “Fire Danger”? A general term used to express an assessment of fixed and variable factors of the fire environment that the determine the ease of ignition, rate of spread, difficulty of control, and fire impact. from Merrill and Alexander (1987) CCFFM Glossary of Forest Fire Management Terms - 4th Edition

Elements or Factors of Fire Danger to Consider

Ignition Risk

Three Components of the Fire Environment

What is “Fire Danger Rating”? The process of systematically evaluating and integrating the individual and combined factors influencing fire danger represented in the form of fire danger indexes. from Merrill and Alexander (1987) CCFFM Glossary of Forest Fire Management Terms - 4th Edition

What is a “Fire Danger Index”? A quantitative indicator of one or more facets of fire danger, expressed in a relative sense or as an absolute measure. from Merrill and Alexander (1987) CCFFM Glossary of Forest Fire Management Terms - 4th Edition

Countryman’s (1966) Concept of Total Fire Danger

Why is Fire Danger Rating Needed? One of the major needs is for a system that will allow a man in charge of a going fire to be less of a gambler and more of a manager. Headley (1943) Re-thinking Forest Fire Control Roy Headley Director of Fire Control U.S. Forest Service, 1919-1941

Comparison of fire management with and without the use of a fire danger rating system (from Van Wilgen and Burgan 1984) Management using formal system

Management without formal system

1. Fire danger is accurately quantified

1. Fire danger is estimated

2. Fire danger can be calculated by newly appointed staff

2. Estimations rely largely on experience

3. Use of the system will force staff to keep records of climatic data, which are of importance to all management procedures

3. No (or very few) climatic records are kept

4. Management decisions are based on quantified indices and are therefore less variable

4. Management decisions are based on experience and vary greatly among individuals

A Panacea?

Ralph M. Nelson Researcher Forester U.S. Forest Service Southern Forest Experiment Station Asheville, NC

I do not want to leave the impression that I think a good system of [fire] danger measurement is the answer to all fire control and management problems. It can be a guide, and a very useful one, but it can never take the place of cool, calculating, and experience judgement. – Nelson (1955)

Applications or Uses of Fire Danger Ratings • Prevention planning (e.g. informing the public of impending fire danger, regulating access and risk associated with public and industrial use of forest and rural areas • Preparedness Planning (i.e., level of readiness and pre-positioning of suppression resources • Detection Planning (e.g., lookout staffing and aircraft scheduling and routing

Applications or Uses of Fire Danger Ratings • Initial Attack Dispatching (e.g., prioritizing of targets for airtankers and ground crews) • Formulating suppression plans on active wildfires (including short-range predictions of fire behavior and growth) • Evaluating fire behavior potential and guidelines for safe work practices for firefighters • Escaped fire situation analysis (including long-range projections of fire growth and behavior)

Applications or Uses of Fire Danger Ratings • Prescribed fire planning and execution, including smoke management • Fire and fuel management modelling and planning

• Fire behavior training

• Wildland fire research

American Pioneer in Forest Fire Research: Harry T. Gisborne

First full-time USFS fire researcher appointed in 1922

Canadian Pioneers in Forest Fire Research: James G. Wright and Herbert W. Beall

Wright initiates FDR research within the federal forest service in 1924. Beall becomes Wright’s summer student in 1928 and obtains a full-time appointment in 1932.

Australian Bushfire Research Pioneers: Alan McArthur and Harry Luke

Trends in Fire Danger Rating Systems Origins: Local Level (starting in the early 30s) Regional Level (up to the mid to late 60s) National Level (recognition in the late 1950s; achieved beginning in the early 1970s) Global Level (recognition of need as early as the late 70s; revitalized interest in 2005)

Historical accounts

Basic Issues in Fire Danger Rating In developing a fire danger rating system, the first issue is to formulate objectives defining what the fire danger rating system should be designed to do. Once that is determined, decisions can be made on the six basic issues of developing an operating system.

Basic Issues in Fire Danger Rating From (Brown and Davis (1973)

• What to measure (i.e. what factors or elements to be measured)? • When to measure (i.e., time of year and time of day)? • Where to measure (i.e., how many points and where should they be located0? • How to measure (e.g., in the forest or in the “open”)? • How to integrate measurements (e.g., determination of joint effects on ignition and spread)? • How to apply danger ratings?

Fire Environment Factors Fuel Characteristics: • Quantity • Moisture and Condition • Size & Shape • Depth/Height • Arrangement Weather Characteristics: • Wind Speed & Direction • Relative Humidity • Air Temperature • Rainfall Amounts & Duration • Cloud Clover • Atmospheric Instability Topographic Characteristics: • Slope Steepness & Aspect • Elevation • Configuration • Barriers to Fire Spread

Fuel Moisture Analogs

Basswood slats

Pondersoa pine dowels

“Large Log Study” (Idaho)

Vegetative Stage or Condition

• Degree of curing in grasslands • Understory and overstory leaf-out in pure hardwood stands and in mixedwood stands • Understory leaf-out in pure conifer stands (i.e., “green surface fuel effect”)

In general, fire danger ratings determined at a basic observation time (e.g., noon LST are intended to apply to the “peak” burning conditions

Designing a fire weather or danger rating station network involves several considerations (e.g., fire occurrence, fuels and topography, values-atstake, cost considerations).

“Open” exposure standard vs. “in-stand” exposure

Traditional sources of data and information for developing fire danger rating systems: • Laboratory studies (e.g., fuel moisture, wind and slope effects on rate of fire spread) • Outdoor experimental fires • Various field studies on live and dead fuel moistures • Wildfire case studies • Individual fire reports

C.E. Van Wagner Fire Research Scientist Canadian Forest Service Petawawa Forest Experiment Station Chalk River, Ontario

Forest fire danger rating is a fascinating but exasperating branch of forest research. The goal is easily stated: Make an index such that any given index value will always represent the same fire behaviour, no matter what weather history leads up to it. The trouble is, one quickly outruns the available practical knowledge and theory. A liberal dose of philosophy is required as well. – Van Wagner (1970)

The Canadian FWI System’s fire behavior indexes are patterned after Byram's (1959) fire intensity concept

I = H · w·r FWI constant BUI ISI - Initial Spread Index (ISI) - Buildup Index (BUI) - Fire Weather Index (FWI)

George M. Byram Physicist USDA Forest Service Southern Forest Experiment Station, Asheville, NC

KBDI Interpretation Guidelines

Danger Rating Scale “Open ended” or “Fixed/Closed”?

Fire Danger Classes (e.g., descriptive term and color code) How many? What to call them? How to delineate them? Meaning?

Delineation of Fire Danger Classes based on Actual Reported Fires in South African fynbos fuel complexes (Van Wilgen and Burgan 1984)

Example of Evaluation of Fire Danger Class Criteria: Major New Zealand Exotic Pine Plantation Widlfires

Form of Presentation US meters Jim Wright’s meter 1935

Canada Department of Forestry Early 60s

Canadian Forest Fire Hazard Recorder

Impacts of Technologies on Fire Danger Rating

Five General Principles of Fire Danger Measurement Nelson (1955)

1. A fairly simple method of measuring key variables such as fuel moisture, wind, and rain, and a way of integrating these variables into numerical values. 2. Close adherence to standards for fire weather station location and instrumentation that established for the particular system in use. 3. Careful training of fire weather observers. 4. Periodic and thorough inspection of fire weather stations. 5. Continuity of fire weather and fire danger records.

Quality control in fire danger rating

Training in fire danger rating

Several key scientific, technological and human elements need to be considered in the developing a national system of fire danger rating

CFFDRS structure diagram and factors that were important in the development and implementation From Taylor and Alexander (2006)

Key Element #1 A modular system of fire danger indicators or models of fire occurrence and behavior in important fire environments developed through a sustained program of scientific research and based on relationships between fire weather, fuels, topography, and ignition sources.

Key Element #2 A reliable technical infrastructure to gather, process, disseminate, and archive fire weather data and forecasts (weather instruments/stations, standards, communications) and fire danger predictions (text and map displays) within operational agencies.

Key Element #3 Guidelines, decision aids, and training for fire managers in the application of fire danger indicators appropriate to the needs and capabilities of operational agencies based on research and operational experience.

Key Element #4 Cooperation between fire management agencies and with research agencies to foster communication, to share resources, and to set common standards for information, resources, and training (policies, cost-sharing agreements, national training courses, working groups).

General Recommendation: Compile Comprehensive Bibliography & Synthesis on Fire Danger Rating

A Caution FIRE DANGER RATING PARADOX (after Rothermel 1987) ¾ The systems aren't accurate enough. ¾ The systems are too complicated. Presumably, crude but reliable decision aids are needed at the field level.

THANK YOU!

Questions? Comments?