Adaptation and Integration of the Canadian Fire Danger Rating System into Wildfire Prevention
Activities in New Zealand
H. Grant Pearce UK Wildfire Prevention Conference Fire Scientist WILDFIRES: PREVENTION BETTER THAN CURE Scion Rural Fire Research Group, NZ 10-11 November 2015, Glasgow
Acknowledgments
• Michael Bruce, Scottish Wildfire Forum & Wildfires 2015 conference chair
• Marty Alexander, Canadian Forest Service (retired)
• Andy Moffat, Forest Research UK – TRANZFOR exchange to NZ (Nov-Dec. 2012)
Content
• Rural fire management in NZ
• The NZ Fire Danger Rating System Adaptation of the Canadian FFDRS NZ fire behaviour models and tools
• Applications of the NZFDRS Wildfire prevention
NZ wildfire problem • Fire not a natural part of NZ ecosystems
• Temperate, maritime climate
• NZ predominantly still “rural” – population 4M, land area 27M ha
• Fire widely used as a land management tool
• Increasing rural-urban interface
• Average 3000 wildfires/year burning 6000 ha, but varies significantly from year to year – majority human-caused,
NZ wildfire problem • average 3300 “rural” fires per year, burning 6000 ha • most are grass or scrub fires
(Source: NRFA Annual Return of Fires)
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f fire
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Forest Scrub Grass No. fires
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4,000
6,000
8,000
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rned
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Num
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f fire
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Area burned No. fires 5-yr average
PresenterPresentation NotesEmber attack occurs when twigs and leaves are carried by the wind and land on houses or other vegetationIt’s the most common way houses catch fire during a wildfire
Wildfire causes •
Current & future fire climate Projected number of days of VH+E Forest fire danger
Current 2040 2090
(Source: Pearce et al. 2011)
PresenterPresentation NotesEmber attack occurs when twigs and leaves are carried by the wind and land on houses or other vegetationIt’s the most common way houses catch fire during a wildfire
Rural fire control in NZ Fire management is responsibility of “Rural Fire Authorities” (RFAs) • urban areas: NZ Fire Service • state lands: Dept. Conservation • territorial authorities: district and city councils • rural fire districts: NZ Defence Force,
forest companies • Moving towards fewer, amalgamated
“Enlarged Rural Fire Districts”
Responsibilities covered under various legislation: • Separate Fire Service and Forest & Rural
Fires Acts • also CDEM Act, RMA, LG Act
PresenterPresentation NotesEmber attack occurs when twigs and leaves are carried by the wind and land on houses or other vegetationIt’s the most common way houses catch fire during a wildfire
Functions of Rural Fire Authorities • promote and carry out rural fire
control measures • appoint Rural Fire Officers • maintain registers:
– fire plan, training, equipment
• assess fire hazards: – weather observations – fire danger rating
• implement fire season restrictions – Open/Restricted/Prohibited fire seasons – activity controls
• other fire control measures – e.g. fuel reduction
23 October 2014
PresenterPresentation NotesEmber attack occurs when twigs and leaves are carried by the wind and land on houses or other vegetationIt’s the most common way houses catch fire during a wildfire
NZ Rural Fire Research • national fire research programme
– established in 1992, now part of Scion (NZ Forest Research Institute)
– 2 full-time researchers, ~4.5 FTEs total – Govt. funded, with stakeholder co-funding
• main focus areas: – describing fuels & fire climate – modelling fire behaviour in NZ fuels – development of NZ Fire Danger Rating
System (NZFDRS) – safety and productivity of firefighters – social fire research – community
resilience, fire danger communications – use of fire as a land management tool
PresenterPresentation NotesEmber attack occurs when twigs and leaves are carried by the wind and land on houses or other vegetationIt’s the most common way houses catch fire during a wildfire
New Zealand Fire Danger Rating System (NZFDRS)
Derived from Canadian equivalent, the CFFDRS • Fire Weather Index (FWI) System
core component • Fire behaviour and fire danger
classes based on Fire Behaviour Prediction (FBP) System
• Fire Occurrence Prediction (FOP) and Accessory Fuel Moisture (AFM) subsystems still under development
• Provides information to support fire management decision-making
FWI System
FBP System
FOP System
New Zealand Fire Danger Rating System
AFM System
Weather Risk of Ignition
Topography Fuels
NZFDRS
Reduction Readiness
Recovery
Fire Management Applications
Response
Fire Weather Index (FWI) System
Adopted by NZ Forest Service in 1980/81 • followed review of FDR systems
FWI chosen because: • simple to use (only
4 weather inputs) • sound scientific basis • interpretive back-up • NZ similar fuels and
climate to B.C. • ratings correlated to
fire behaviour
Fire Weather Index (FWI) System
NZ modifications for: • season reversal • NZ daylength factors
(for DMC and DC) Contained in NZ version of FWI Tables and equations Minimal system validation: • FFMC with pine litter MC%, • DC with soil types/MC%
Fire Danger Rating Outputs Should answer the question: “What is the probability of a fire starting, spreading and doing damage today?” Fire potential: • Indication of expected
burning conditions – ease of ignition – potential spread rates – fire intensity – fire size and shape
• Plus potential impact – difficulty of control – damage potential
NZ Fire Danger Classes
• Principal use is for notifying the public
• Fire danger classes based on head fire intensity – determined from fuel load and
potential rate of fire spread • Related to suppression
effectiveness • Models available for Forest,
Grassland and Scrubland fuel types from FBP System
Fire Danger Class
Fire Intensity (kW/m)
Control Requirements
L < 10 Ground crews with hand tools
M 10-500 Ground crews with back- pack pumps
H 500-2000 Water under pressure and/or heavy machinery
VH 2000-4000 Aircraft using chemical fire retardants
E > 4000 Very difficult if not impossible to control
Fire Danger Classes
Forest Fire Danger
Class
Forest: • based on ISI and BUI • estimates intensity based
on potential spread rate and fuel loading
Fire Danger Classes Grass: • based on ISI and degree of
grass curing fire spread • assumes standard grass fuel
load (3.5 t/ha)
Grassland Fire Danger
Class
Degree of Grass Curing
(%)
Fire Danger Classes
Scrubland Fire Danger
Class
Scrub: • based on FFMC and wind
speed ( ISI) • assumes standard scrub fuel
load (20 t/ha)
Scrubland Fire Danger Class Graph
0
10
20
30
40
50
60
50 60 70 80 90 100
Fine Fuel Moisture Code (FFMC)
10-m
Ope
n W
ind
Spee
d (k
m/h
)
Low
Extreme
Very High
High
Moderate
• Current fire weather and fire danger updated daily from network of 200+ weather stations
• Forecasted weather used to calculate hourly (2 days) and daily (6 days) FWI values
• fire manager access via FWSYS software application
• public access via Internet: nrfa.fire.org.nz/fire_weather
Fire Weather System
Fire Behaviour Prediction (FBP) System
Primary outputs:Head fire rate of spread, Fuel load/consumption,
Head fire intensity,
Primary outputs:Head fire rate of spread, Fuel load/consumption,
Head fire intensity,
Secondary outputs:Spread distances,
Flank & back fire ROS & I, Area, Perimeter,
PGR and L/B ratio
Secondary outputs:Spread distances,
Flank & back fire ROS & I, Area, Perimeter,
PGR and L/B ratio
FuelsFuels WeatherWeather TopographyTopographyFoliar
moisturecontent
Foliarmoisturecontent
Type &duration ofprediction
Type &duration ofprediction
Fire Behaviour Prediction(FBP) System
Fire Behaviour Prediction(FBP) System
FBP SystemFuel Type
FFMC, ISI & BUI,
Wind speed& direction
Slope angle&
Aspect
Elevation,Lat./Long.,
Date
Elapsed time,Point or Line
ignition
Primary outputs:Head fire rate of spread, Fuel load/consumption,
Head fire intensity,
Primary outputs:Head fire rate of spread, Fuel load/consumption,
Head fire intensity,
Secondary outputs:Spread distances,
Flank & back fire ROS & I, Area, Perimeter,
PGR and L/B ratio
Secondary outputs:Spread distances,
Flank & back fire ROS & I, Area, Perimeter,
PGR and L/B ratio
FuelsFuels WeatherWeather TopographyTopographyFoliar
moisturecontent
Foliarmoisturecontent
Type &duration ofprediction
Type &duration ofprediction
Fire Behaviour Prediction(FBP) System
Fire Behaviour Prediction(FBP) System
FBP SystemFuel Type
FFMC, ISI & BUI,
Wind speed& direction
Slope angle&
Aspect
Elevation,Lat./Long.,
Date
Elapsed time,Point or Line
ignition
Fire Behaviour Prediction (FBP) System
Empirical field approach through collection of fire behaviour data in different vegetation types • small-scale experimental burning trials (120+) • opportunistic wildfires (including historic events) (40+)
Correlation of FWI System outputs with fire behaviour characteristics
Currently 18 identified fuel types: • 6 plantation forest • 2 indigenous forest • 2 pasture grassland • 2 crop stubble • 2 tussock grassland • 4 scrub
Models for: • rate of spread • available fuel load
NZ Fire Behaviour Prediction System
NZ tools - fire behaviour field manual
Look-up tables for predicting fire behaviour in NZ fuel types • simple tables
− fuel loads − rates of spread − fire intensity & flame size − fire area & perimeter length/growth
• fire behaviour interpretation info − suppression effectiveness − firebreak breaching
• step-by-step instructions • fire behaviour prediction worksheet • field documentation forms
NZ tools – Fire Behaviour Toolkit PC software
Software for predicting fire behaviour in NZ fuels • Calculator & Worksheet modules
• Flame length & Firebreak breaching calculators
• Rules of thumb & Suppression productivity info
NZ tools – Fire Behaviour Toolkit smart app
Smartphone application of Toolkit calculator • Calculator input & output screens
• Also Worksheet module
• Android and Apple versions available
NZ tools – Prometheus fire growth model
Software that simulates fire spreading across the landscape • Combines GIS data on fuel types
& topography with fire weather data & fire behaviour models
• Based on Prometheus fire growth model developed in Canada
• Re-developed using fire behaviour models for NZ fuel types
• Validated against several NZ wildfires
FWI System – provides numerical ratings of the relative fire potential in a standard fuel type (i.e., a mature pine stand) on level terrain, based solely on weather observations measured daily at noon local standard time (1300 DST). FBP System – provides quantitative fire behaviour estimates for major fuel types and topographic situations based on FWI System and fire weather observations for the time of the prediction.
Fire Danger vs Fire Behaviour Prediction systems
Fire Occurrence Prediction (FOP) In Canada, have used historical fire data to develop predictive relationships for fire starts in different fuel types, based on FWI System components (Wotton et al.) • Lightning – DMC • Human-caused – FFMC and proximity to roads, etc.
Also probabilities of sustained ignition (Lawson et al.) • Fuel moisture codes (DMC/DC or BUI) and wind speed (or ISI)
NZ – grass ignition thresholds
Ignitions in fully cured grasses from: • metal sparks – cutting, grinding • hot vehicle exhausts • open flame - dependent on FFMC
and wind speed
Used to control spark- hazardous activities, and off-road vehicle access
NZ – scrub ignition and spread
Thresholds for ignition and fire spread in exotic gorse scrub: - dependent on FFMC - also relationship between FFMC
and elevated dead fuel moisture content
Used to aid setting of prescriptions and permit conditions for prescribed burns
Successful fire management depends on effective:
• fire prevention • fire detection • pre-suppression preparedness • fire suppression
PresenterPresentation NotesMitigation of the risks associated with wildfires also requires a management approach, and it is commonly recognised that there are four key stages or activities required for successful fire management.
New Zealand Fire Danger Rating System (NZFDRS)
Derived from Canadian equivalent, the CFFDRS • Fire Weather Index (FWI) System
core component • Fire behaviour and fire danger
classes based on Fire Behaviour Prediction (FBP) System
• Fire Occurrence Prediction (FOP) and Accessory Fuel Moisture (AFM) subsystems still under development
• Provides information to support fire management decision-making
FWI System
FBP System
FOP System
New Zealand Fire Danger Rating System
AFM System
Weather Risk of Ignition
Topography Fuels
NZFDRS
Reduction Readiness
Recovery
Fire Management Applications
Response
Fire management applications
• preparedness planning • detection planning • initial attack dispatching • fire suppression tactics & strategies • escaped fire situation analysis • prescribed fire planning & execution • fire behaviour training • prevention planning
Applying outputs of NZFDRS
Normal approach to fire behaviour prediction:
Weather FWIs + Fuel type + Slope Fuel load + ROS Intensity Area/Perimeter Impacts + Resources required etc. Applications often involve “reverse engineering” of FWI and FBP System relationships:
Preventing fire start and spread in grass fuels: Probability of ignition FFMC (+ Wind speed) & Spread potential ROS ISI + Grass curing
Fire Prevention: “activities directed at reducing fire occurrence ... ”
(Merrill and Alexander 1987) Reduction in the number of wildfires results in: reduced area burned reduced fire suppression costs less environmental and social impacts lower risks to firefighters and the public
Examples of fire prevention: public notification of fire danger publicity campaigns fire season status fire permit issue restrictions or closures fuels management fuel reduction burning
• most effective if targeted, and based on fire danger
Grassland Curing Buildup Index (BUI) (%) 0 - 25 25 - 50 50 - 80 >80
0 - 60 Open Open Restricted Restricted
60 - 80 Open Restricted Restricted Prohibited
>80 Restricted Prohibited Prohibited Prohibited
Prevention example: Canterbury/West Coast Regional Rural Fire Committee (CWCRRFC) agreed trigger points for fire season declarations
Guidelines for Restricted and Prohibited Fire Seasons
Grassland Curing
Buildup Index (BUI)
(%)
0 - 25
25 - 50
50 - 80
>80
0 - 60
Open
Open
Restricted
Restricted
60 - 80
Open
Restricted
Restricted
Prohibited
>80
Restricted
Prohibited
Prohibited
Prohibited
Prevention example: Forestry company activity controls for fire awareness, public access and forestry operations
Hazard Levels
Fire Awareness
Public Access Restrictions
Silvicultral Restrictions
Harvesting Restrictions
Level 1 (BUI 0 - 30)*
Fire permits issued as per fire plan.
At discretion of land owner.
As per fire plan. As per fire plan.
Level 2 BUI (31 - 45)
Review fire permit issue.
As above. Increase awareness of fire danger level.
Increase awareness of fire danger level.
Level 3 BUI (46 - 54)
Cancel issued fire permits. Start public awareness campaign.
Restricted access to high risk areas. Initiate fire patrols. Initial Attack crew located at fire depot.
Initiate work site patrols Continue work area inspections and fire danger awareness.
Initiate work site patrols. Continue work area inspections and fire danger awareness.
Level 4 BUI (55 - 99)
Fire prohibition decision by PRFO.
Cancel public access to production forests. Initial Attack crews at strategic points.
Midday knockoff for all chainsaw operations. Restrict work to lower hazard areas.
Midday halt of chainsaws in forest. Processing of logs on landings until 2 pm.
Level 5 BUI (100 - 159)
As above. Review closing high risk public areas.
Halt all chainsaw operations. Place workers on fire standby.
Halt machine operations in high hazard cutover and scrub areas.
Level 6 BUI (160+) * BUI = Buildup Index from FWI System
Regional emergency declared.
Close production forests, public areas and forest roads. Fire patrols and Initial Attack crews only.
No operations. All workers on full availability for fire control operations.
No operations. All workers on full availability for fire control operations.
NZ Wildfire Threat Analysis System Strategic fire management planning tool
- enables development of appropriate strategies and priorities for mitigating identified threat
Quantifies Wildfire Threat based on
the combination of: - Risk = ignition potential - Hazard = fire behaviour potential - Values-at-risk
SLOPESLOPE FUEL LOADFUEL LOAD
FUEL TYPESFUEL TYPES
NZ Wildfire Threat Analysis System Hazard component indicates
fire behaviour potential using NZFDRS outputs - available fuel loads (AFL) from land cover - rate of spread (ROS) for each fuel type
using FWI relationships - adjustment of rate of spread for slope (ROSslope) - Byram’s head fire intensity (HFI) from slope-corrected
rate of spread (ROSslope) and fuel load (AFL)
SLOPESLOPE FUEL LOADFUEL LOAD
FUEL TYPESFUEL TYPES
AFL FWI ROSslope HFI
Strategic & Tactical Fire Management Plans Regional and local area plans for responding to
identified Wildfire Threat
- Strategic – prioritization of strategies for mitigating identified threat, including fire prevention activities
- Tactical – work program for mitigation activities
e.g. fire danger “triggers” for restricting high fire risk activities
Roadside mowing
• Simple trigger levels based on grass curing and FFMC – FFMC = ease of ignition, Curing = potential for fire spread
FFMC 8596
Curing (%)
Level 1 - no controls (tools required)Level 2 - firefighting/water requiredLevel 3 - restricted hours (morning)
Level 4 - no mowing
PresenterPresentation NotesTrigger for roadside mowing, based on curing and FFMC.Suggest having 4 levels of restriction:from unrestricted/no controls at low fire danger levels (but still carrying basic firefighting equipment as standard), through requiring availability of additional firefighting capability including a mobile water supply, to restricting hours of work to periods outside the mid-afternoon peak fire danger period (e.g. to mornings), to shutting down mowing operations altogether under the most severe fire danger conditions, when any fires that do start will be too intense to put out and have the potential to spread very rapidly and become large fires.
Grass Triggers • Communicate activity controls using a Risk Treatment Guide
PresenterPresentation NotesThe intention is to summarise each of the activity triggers as a Risk Treatment Guide
Conclusions
NZ adopted Canadian FFDRS, and adapted it to local environment • minor modifications to FWI System • development of NZ FBP System
Used to inform a range of fire management applications, including fire prevention
FWI System
FBP System
FOP System
New Zealand Fire Danger Rating System
AFM System
Weather Risk of Ignition
Topography Fuels
NZFDRS
Reduction Readiness
Recovery
Fire Management Applications
Response
Conclusions Difficult to gauge success of fire prevention activities • Poor quality control of wildfire incident data • Limitations to fire cause data, but is improving through greater
focus on fire investigation
Conclusions Major shift in focus by NZ fire agencies from response to reduction (fire prevention)
Plans for farmer training to address escapes from land management burns
Prevention activities well supported by fire science
More research planned into fire occurrence from other fire causes and in different fuel types, e.g. • more mechanised forestry harvesting • ignition and spread thresholds in native shrublands • fire occurrence in temperate native forests
Adaptation and Integration of the Canadian Fire Danger Rating System into Wildfire Prevention Activities in New ZealandAcknowledgmentsContentNZ wildfire problemNZ wildfire problemWildfire causesCurrent & future fire climateRural fire control in NZFunctions of Rural Fire AuthoritiesNZ Rural Fire ResearchNew Zealand Fire Danger Rating System (NZFDRS)Fire Weather Index (FWI) SystemFire Weather Index (FWI) SystemFire Danger Rating OutputsNZ Fire Danger ClassesSlide Number 16Slide Number 17Slide Number 18Fire Weather �SystemFire Behaviour Prediction (FBP) SystemFire Behaviour Prediction (FBP) SystemSlide Number 22Slide Number 23NZ tools - fire behaviour field manual NZ tools – Fire Behaviour Toolkit PC software NZ tools – Fire Behaviour Toolkit smart appNZ tools – Prometheus fire growth model Slide Number 28Fire Occurrence Prediction (FOP)Slide Number 30Slide Number 31Slide Number 32New Zealand Fire Danger Rating System (NZFDRS)Fire management applicationsApplying outputs of NZFDRSSlide Number 36Slide Number 37Slide Number 38Slide Number 39Slide Number 40Slide Number 41Slide Number 42Slide Number 43Slide Number 44ConclusionsConclusionsConclusions