Example 3: 



The Honey Fire of January 25, 1938, was documented by Olsen 

 (1941) with detailed plotting of the perimeter during the first 

 hour. The fire burned predominantly in broomsedge (Andro- 

 pogan sp.) and other grasses to provide a uniform, extremely 

 dense fuel bed. Wind measurements were made at 3.5 ft (1.1 m) 

 above the ground and indicated a maximum wind of 9.9 mi/h 

 (15.8 km/h). However, the l/w ratios for the period of 1(X)5 to 

 1025 indicate windspeeds on the fire of 19 to 20 mi/h (30.4 to 

 32.0 km/h) were present. The difference could be due to vari- 

 ability in the wind or may be due to the fuels having a larger 

 surface area to volume ratio than the ponderosa pine needles 

 fuel bed used by Fons. The fire shapes in figure 1 1 were closely 



matched by the double ellipse equations. Note in figure 7 

 that the fu-e accelerated during the first 10 minutes, and then 

 stabilized at a nearly constant //w ratio. Spot fires later 

 in the bum period show similar fire shapes. Spot fire "F" 

 that burned just after 1230 had a //w ratio at 1233 of 6.1:1, 

 which from figure 6, or equation 17, corresponds to an average 

 wind on the fire of about 16 mi/h (25.6 km/h). This is within 2 

 mi/h (3.2 km/h) of the maximum wind between 1220 and 1233 

 hours. An hour later spot fire "G" developed a shape with a 

 i/w ratio of 3.5: 1 , which indicates a wind decrease to about 

 1 1 mi/h (17.6 km/h). The narrative indicates these spot fires in 

 the eastern, portion of the burned area were in blackjack oak 

 (Quercus marilandica) stand with less fire-carrying fuel. The fire 

 was contained in this area at 1443 hours. 



Example 3. The Honey Fire of Louisiana burned through broomsedge 

 {Andropogon sp.) and other grasses on January 25, 1983. 



Variable 



Documented 



Simple ellipse 



Double ellipse 



Double ellipse 





values 



values 



values 



adj. values 



Time 



0955 hours 









Area 



.9 acres 



.9 



1.4 



.9 



Perimeter 



.2 miles 



.2 



.2 



.2 



Distance 



.1 miles 



.1 



.1 



.1 



Windspeed 



6.7 mi/h 





6.7 



8.4 





2.7:1 



3.4:1 



2.3:1 



2.7:1 



Time 



1000 









Area 



10.2 



10.2 



31.3 



10.2 



Perimeter 



.9 



.9 



1.0 



.8 



Distance 



.4 



.4 



.4 



.4 



Windspeed 



9.9 





9.9 



19 



{l\N 



8.4:1 



9.3:1 



3.1:1 



8.4:1 



Time 



1005 









Area 



27 



27 



96 



27 



Perimeter 



1.5 



1.5 



1.7 



1.5 



Distance 



.7 



.8 



.7 



.7 



Windspeed 



9.9 





9.9 



21 



tlw 



10.5:1 



10.5:1 



3.1:1 



10.5:1 



Time 



1010 









Area 



60.5 



60.5 



254 



60.5 



Perimeter 



2.4 



2.4 



2.8 



2.3 



Distance 



1.2 



1.2 



1.2 



1.1 



Windspeed 



9.9 





9.9 



21.1 



(Iw 



10.6:1 



12.4:1 



3.1:1 



10.6:1 



Time 



1015 









Area 



109 



109 



462 



109 



Perimeter 



3.3 



3.3 



3.8 



3.1 



Distance 



1.6 



1.6 



1.6 



1.5 



Windspeed 



9.9 





9.9 



21.2 



fl\N 



107:1 



12.4:1 



3.1:1 



10.7:1 



Time 



102p.O 









Area 



167.0 



167 



640 



167 



Perimeter 



3.9 



3.9 



4.4 



3.6 



Distance 



1.9 



1.9 



1.9 



1.8 



Windspeed 



9.9 





9.9 



20.3 



i/w 



9.7:1 



11.3:1 



3.1:1 



9.7:1 



Time 



1025 









Area 



250.8 



250.8 



911.6 



250.8 



Perimeter 



4.6 



4.6 



5.3 



4.4 



Distance 



2.2 



2.3 



2.2 



2.2 



Windspeed 



9.9 





9.9 



20.2 





9.6:1 



10.5:1 



3.1:1 



9.6:1 



13 



