1. WILDLAND FIRE SUPPRESSION NEEDED: INITIAL-ATTACK SUCCESS
Presentation by Frank Greulich 1

2. AIRTANKER RETARDANT DROPS2 3
AIRTANKER RETARDANT DROPS 4 5

3. MODEL OVERVIEW
A spreadsheet based procedure for estimating airtanker initial-attack performance
Exceptional precision and flexibility in specifying the spatial distribution of fire starts
Exact flight-distance moments are computed and then applied in a user friendly model

4. COST ESTIMATION EXAMPLE
Use of Dobson's data (1965) to estimate the cost of the Canadair CL-215 for "one-strike initial-attack" as described by Hodgson and Newstead (1978) and McDonald (1979).

5. DOBSON’S DATA Cost = 1.15 + 0.0891 Dist + 0.0449 Dist2
Where cost is given in cents per litre of airdropped water and Dist(ance) is the one-way flight distance from the airbase to the fire in 100’s of kilometers

6. ONE-STRIKE INITIAL-ATTACK
In the “one-strike initial-attack” model for skimmer aircraft it is assumed that it will drop water scooped from nearby sources until refueling becomes necessary thus ending initial-attack by that particular aircraft.

7. MODEL ANALYSIS A Microsoft Excel program is used to
analyze the airtanker initial-attack model
- Existing airbases can be evaluated
- The optimal airbase location can be identified
- Constrained optimization of airbase location
may be done

8. INITIAL-ATTACK REGION - 1st EXAMPLE

9. MODELLING RESULTS - 1st EXAMPLE

10. GENERATING MODEL RESULTS6
GENERATING MODEL RESULTS
Define the regions with bounding line segments
Assign fire occurrence probabilities to each region
Locate the airbase if appropriate
Enter the constraint(s) if appropriate
Run the Excel program and examine results

11. INITIAL-ATTACK REGION - 2nd EXAMPLE

12. MODELLING RESULTS - 2nd EXAMPLE

13. COMPARATIVE ADVANTAGES
- Generates exact moments of the flight-distance distribution
- Models areas, lines and points as possible fire-start
locations
- Provides exceptionally fast computational speeds including
optimization
- Employs a commonly available and familiar spreadsheet
program
- Offers high internal consistency due to its programming
simplicity
- Is solidly based on analytical procedures vetted through
refereed-journal articles

14. MODEL DEVELOPMENT - NEXT PHASE
Front-end for GIS data importing
Excel macros for data formatting
Scaled-up proof-of-concept run

15. REFERENCES CITED
1. Dobson, N.R "The economics of the Canadair CL-215 in the waterbomber and passenger transport roles." Canadair Ltd., Montreal, Quebec. OER p.
2. Hodgson, M.J. and R.G. Newstead “Location-allocation models for one-strike initial attack of forest fires by airtankers.” Can. J. For. Res. 8(2):
3. McDonald, C.S “Air tankers in Alberta.” In: Proceedings of the International Fire Management Workshop, Oct. 31 – Nov. 1, D. Quintilio (ed.), Edmonton, Alberta. Northern Forest Research Centre Information Report NOR-X p.

16. PICTURE CREDITS 1 John McColgan, Fairbanks, Alaska2 3 4 5 6