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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Forest Scrub Grass No. fires

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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