Abstract:
This study analyzes past forest fire behavior on a selected area
in the Oregon Cascades in an attempt to evaluate level of fire hazard
on selected vegetational areas. Vegetational areas were defined in
five broad classes: Merchantable Douglas-fir Stands, Non-merchantable
Douglas-fir Stands, Oak- Madrone Stands, Non- forest
Lands, and Non-stocked Forest Lands. Rate of spread, difficulty of
control, and final size were used as indications of fire behavior.
Fire weather severity, slope steepness, aspect, and the vegetational
cover type in vicinity of the fire were the environmental factors
considered. Five hundred twenty-four fires were sampled in this
analysis.
The data were fitted to a statistical model for analysis. From
this analysis, the importance of the environmental factors on rate of
spread, difficulty of control, and final size was tested; tri-variate
response surfaces were developed, representing rate of fire spread
and difficulty of control according to each vegetational cover type.
There were marked differences in the rate of fire spread and
resistance to control of a fire in the five generalized cover types
studied. Each vegetational cover type, therefore, possesses certain
characteristics that suggest a certain level of fire hazard existing
during the fire season.
