key elements of the national fire danger rating system for south africa
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Key elements of the National Fire Danger Rating System for South Africa. The nature of a National Fire Danger Rating System. Adoption of a model: Candidate Models. - McArthur Forest Model - McArthur Grassland Model - US Model - Lowveld Model. - PowerPoint PPT PresentationTRANSCRIPT
Key elements of Key elements of the National Fire the National Fire Danger Rating Danger Rating
System for South System for South AfricaAfrica
The nature of a National Fire Danger Rating System
Climate and Risk
Fire danger regions map
Daily data for region: Fuel condition Forecast and actual
weather
Fire danger model
Users in each region
Collect fire occurrence
data
Forecast and actual fire danger rating for regions
Fire danger rating table
Vel
dfire
Info
rmat
ion
Sys
tem
Communicate
Outputindex
Rating
Monitor and improve
Input region data
Monitor and improve
Monitor and improve
Climate and Risk
Fire danger regions map
Daily data for region: Fuel condition Forecast and actual
weather
Fire danger model
Users in each region
Collect fire occurrence
data
Forecast and actual fire danger rating for regions
Fire danger rating table
Vel
dfire
Info
rmat
ion
Sys
tem
Communicate
Outputindex
Rating
Monitor and improve
Input region data
Monitor and improve
Monitor and improve
Adoption of a model: Candidate Models
- McArthur Forest Model- McArthur Grassland Model- US Model- Lowveld Model
United States Model McArthur Grassland Model
McArthur Forest Model Lowveld Model
Design Principles Physical models Empirical models Empirical models Not documented
Model Complexity Complex Simple Simple Simple
Inputs Fuel models and readily available weather data
Requires weather and curing estimates. A range of methods are available
for estimating curing, some expensive, others
subjective.
Only readily available weather
data needed
Only readily available weather
data needed
Degree of User Sophistication Required
High – User needs to have understanding of
all the station parameters that are embedded within the
model
Moderate – User needs to asses curing estimates Low
Low - if applied without rainfall
correction factors, otherwise moderate
Ability to Model Green-up and Curing
Green up and curing based on modelled fuel moisture, and effects
simulated by transfer of herbaceous fuel loads to the dead fuel category
Uses curing estimates directly None None
Similarities and differences between candidate models
United States Model McArthur Grassland Model
McArthur Forest Model
Lowveld Model
Modelling of Fuel Moisture Yes No No No
Ability to deal with Fuel Loads
Yes, but currently limited to 20 standard fuel models No No No
Output Indicator Values
Burning IndexEnergy Release ComponentSpread ComponentIgnition Component
Fire Danger IndexFire Danger
Index Fire Danger Index
Ability to Deal with Daily and Seasonal Planning
High (Daily and Seasonal Planning) Low (Daily Planning only) Low (Daily
Planning only) Low (Daily Planning only)
Potential for Application of Indicator Values to different aspects of
Veldfire Management
High – Many indicator values
Moderate – Long-term simulator of drought through
the estimation of curing
Low – Only a single indicator
value
Low – Only a single indicator value
Available Software Yes – Public Domain Yes – Public Domain Yes – Public Domain
Yes – Available from Lowveld Fire Protection
Association
Use in South AfricaTested in South Africa in the
1980’s, but not currently used
Not used Not used
Lowveld Fire Protection Association, Kwa-Zulu Natal
Midlands Fire Protection Association and South
African Weather Services
Additional features embedded in software KBDI None KBDI None
• McArthur Forest ModelMcArthur Forest Model: Unable to deal with : Unable to deal with green-up and curing.green-up and curing.
• McArthur Grassland ModelMcArthur Grassland Model: Green-up and : Green-up and curing requires estimates. curing requires estimates.
• Lowveld ModelLowveld Model: Unable to deal with green-up : Unable to deal with green-up and curing and has no basis in theory.and curing and has no basis in theory.
• US NFDRS ModelUS NFDRS Model: Ability to model fuel : Ability to model fuel moisture content, model green-up and curing and moisture content, model green-up and curing and provides many indices that address different provides many indices that address different aspects of fire danger.aspects of fire danger.
Selection of a Fire Danger Rating Model
• The Act requires that the model must underpin a system that will assist in the identification of dangerous activities, and of the precautions that should be taken, for for each ratingeach rating
• Model should be able to support a range of activities related to fire management under conditions of low or moderate fire danger (e.g. being able to decide whether or not to initiate prescribed burns based on the risk of a prescribed burn becoming uncontrollable).
Support for Integrated Veldfire Management
Support for Integrated Veldfire Management
• Burning IndexBurning Index• Energy Release ComponentEnergy Release Component• Keetch-Byram Drought IndexKeetch-Byram Drought Index• Spread ComponentSpread Component• Ignition ComponentIgnition Component
Fire Danger Ratings
Classification Description of ClassificationInsignificant The fire danger is so low that no precaution is needed
Low Fires including prescribed burns may be allowed in the open air on thecondition that persons making fires take reasonable precautions against firesspreading
Moderate The fire danger is such that no fires may be allowed in the open air exceptthose that are authorised by the Chief Fire Officer of the local fire service andthose in designated fireplaces; authorised fires may include prescribed burns
High The fire danger is such that no fires may be allowed under any circumstancesin the open air
Extremely High The fire danger is such that no fires may be allowed under any circumstancesin the open air, and special emergency fire preparedness measures must beinvoked
Veldfire Risk Assessment
• A need to identify areas of uniform riskA need to identify areas of uniform risk
• RISK = Likelihood + ConsequenceRISK = Likelihood + Consequence
• Determine vegetation types for the 6 biomes in Determine vegetation types for the 6 biomes in South Africa.South Africa.
• Classified veldfire risk for each vegetation type. Classified veldfire risk for each vegetation type.
• Overlay municipality boundaries over Overlay municipality boundaries over vegetation type map.vegetation type map.
Likelihood of FireVegetation Type Vegetation Type Likelihood of FireLikelihood of Fire
ForestForest Rare: 1 in 100 yearsRare: 1 in 100 years
ThicketThicket Rare: 1 in 100 yearRare: 1 in 100 year
Arid WoodlandArid Woodland Possible: 1 in 10 yearsPossible: 1 in 10 yearsMoist WoodlandMoist Woodland Likely: 1 in 5 yearsLikely: 1 in 5 yearsSparse Arid WoodlandSparse Arid Woodland Rare: 1 in 100 yearsRare: 1 in 100 years
Succulent KarooSucculent Karoo Rare: 1 in 100 yearsRare: 1 in 100 years
Nama KarooNama Karoo Unlikely: 1 in 20 yearsUnlikely: 1 in 20 years
Grassy Nama KarooGrassy Nama Karoo Possible: 1 in 10 yearsPossible: 1 in 10 years
Coastal GrasslandCoastal Grassland Likely: 1 in 5 yearsLikely: 1 in 5 years
Sour GrasslandSour Grassland Almost certain: 1 in 2 yearsAlmost certain: 1 in 2 years
Consequence of Fire (Australian Std. 1999)
Level of Consequence Social, Economic & Environmental Vulnerability Criteria
1. Catastrophic Death, depressed economy, permanent loss of species or habitats
2. Major Extensive injuries, serious financial loss, habitat destruction
3. Moderate Require medical treatment, damage to property, serious impact on the environment
4. Minor Minor injuries, minor financial loss, discernable environmental impacts
5. Insignificant No injuries, no damage to property, minor impact on the environment
Levels of Risk (Australian Std. 1999)
Likelihood Rating
Insignificant
H
M HRare L L L
H E
Unlikely L L M H E
Possible L M H
E
Likely L M H E E
Almost certain M M E
Consequence Rating
Minor Moderate Major Catastrophic
Risk Classification of MunicipalitiesFire danger
regionName of
municipalityWildland Fire Risk
Level
Cannon Rocks to Kei River
Ndlambe H
Great Kei E
Buffalo City E
Ngqushwa E
Plettenberg Bay to Cannon Rocks
Sunday's River Valley L
Kouga H
Kou-Kamma H
Fire Danger Regions of South Africa
• The Act requires the country to be The Act requires the country to be divided into fire danger regions. divided into fire danger regions.
• 53 weather forecasting districts collapsed 53 weather forecasting districts collapsed into 42 fire danger regions on the basis of into 42 fire danger regions on the basis of similar levels of risk.similar levels of risk.
• Each region is to be such that the fire Each region is to be such that the fire danger is sufficiently uniform to allow for danger is sufficiently uniform to allow for a single rating which is meaningful for the a single rating which is meaningful for the entire region.entire region.
Fuel models to be used in each region
Fuel model B - California Chaparral:Fuel model B - California Chaparral: MMany of the any of the fuel model properties embedded within the fuel fuel model properties embedded within the fuel model adequately represent the fynbos vegetation model adequately represent the fynbos vegetation characteristics found in South Africa.characteristics found in South Africa.
Fuel Model C - Pine-Grass Savanna:Fuel Model C - Pine-Grass Savanna: GGrasslands rasslands are a predominant fuel complex in South Africa, are a predominant fuel complex in South Africa, and these grasses experience cycles of green-up and these grasses experience cycles of green-up and curing. Fuel model C has a significant load of and curing. Fuel model C has a significant load of fine dead and live herbaceous (grass) fuel, and as fine dead and live herbaceous (grass) fuel, and as such it should simulate green-up and curing such it should simulate green-up and curing through the year.through the year.
Fuel model allocation to fire danger regions
Fire Danger Region Dominant Vegetation Type
US Fuel Model
Cannon Rocks to Kei River Moist Woodland Pine-Grass Savanna
Eastern Midlands Sour Grassland Pine-Grass Savanna
Northern Interior Grassland Pine-Grass Savanna
Plettenberg Bay to Cannon Rocks
Fynbos California Chaparral
South East Karoo Fynbos California Chaparral
South Interior Midlands Sour Grassland Pine-Grass Savanna