A New Approach to Wildland Fire Management in South Africa

1
Key elements of the National Fire Danger Rating
System for South Africa
2
The nature of a National Fire Danger Rating System
3
Adoption of a model Candidate Models

• - McArthur Forest Model
• - McArthur Grassland Model
• - US Model
• - Lowveld Model

4
Similarities and differences between candidate
models
5
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6
Selection of a Fire Danger Rating Model

• McArthur Forest Model Unable to deal with
  green-up and curing.
• McArthur Grassland Model Green-up and curing
  requires estimates.
• Lowveld Model Unable to deal with green-up and
  curing and has no basis in theory.
• US NFDRS Model Ability to model fuel moisture
  content, model green-up and curing and provides
  many indices that address different aspects of
  fire danger.

7
Support for Integrated Veldfire Management

• 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 each 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).

8
Support for Integrated Veldfire Management

• Burning Index
• Energy Release Component
• Keetch-Byram Drought Index
• Spread Component
• Ignition Component

9
Fire Danger Ratings
10
Veldfire Risk Assessment

• A need to identify areas of uniform risk
• RISK Likelihood Consequence
• Determine vegetation types for the 6 biomes in
  South Africa.
• Classified veldfire risk for each vegetation
  type.
• Overlay municipality boundaries over vegetation
  type map.

11
Likelihood of Fire
12
Consequence of Fire (Australian Std. 1999)
13
Levels of Risk (Australian Std. 1999)
 
 
 
14
Risk Classification of Municipalities
15
Fire Danger Regions of South Africa

• The Act requires the country to be divided into
  fire danger regions.
• 53 weather forecasting districts collapsed into
  42 fire danger regions on the basis of similar
  levels of risk.
• Each region is to be such that the fire danger is
  sufficiently uniform to allow for a single rating
  which is meaningful for the entire region.

16
Fuel models to be used in each region
Fuel model B - California Chaparral Many of the
fuel model properties embedded within the fuel
model adequately represent the fynbos vegetation
characteristics found in South Africa. Fuel Model
C - Pine-Grass Savanna Grasslands are a
predominant fuel complex in South Africa, and
these grasses experience cycles of green-up and
curing. Fuel model C has a significant load of
fine dead and live herbaceous (grass) fuel, and
as such it should simulate green-up and curing
through the year.
17
Fuel model allocation to fire danger regions