THE AUTHOR 



HAL E. ANDERSON has been team leader of the basic 

 research section of the Fire Fundamentals Research Work 

 Unit since 1979. He joined the staff at Intermountain Sta- 

 tion's Northern Forest Fire Laboratory in Missoula, Mont., 

 in 1961 and served as project leader of the fire physics 

 project from 1962 to 1966 and of the fuel science project 

 from 1966 to 1979. He previously w/orked with General 

 Electric Company from 1952 to 1961 on thermal and 

 nuclear instrumentation. He received his B.S. degree in 

 physics from Central Washington University in 1952. 



Fire behavior predictions have become part of the initial 

 fire assessment, both for fire as a treatment or fire as a 

 force to be suppressed. How fast a fire may grow in size 

 and how much fireline there may be are valuable informa- 

 tion factors to fire management staff. Critical analysis of 

 wild land fire records and previous wind tunnel research 

 on fire growth provided the basis for a mathematical ap- 

 proach to estimating fire size and shape using a double 

 ellipse model. Equations have been developed to estimate 

 the flank and backing fire spread rates, fire area, perim- 

 eter, and length to width ratio, and to plot fire shape. 



Graphs and tables present the relationships developed, 

 and five wild land fires show how the estimation matches 

 field situations. In addition, the simple ellipse concept is 

 presented with a quadratic equation solution for determin- 

 ing minor and major axes. These results are compared to 

 the fire size and perimeter tables carried in most fireline 

 notebooks. 



RESEARCH SUMMARY 



CONTENTS 



Page 



Comparison to Field Observations of Wildfires 



Conclusions 



Publications Cited 



Appendix I 



Appendix II 



Development of Fire Shape Model . . 

 Analysis Related to Fire Size and Shape 



Introduction 

 Background 



Comparison of Fire Size Properties 



Experimental Results of 1939 



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