Fire Growth Maps for the 1988 Greater Yellowstone Area Fires

This research effort was initiated soon after the fires were
over to reconstruct the fire behavior and the conditions that
produced 3 months of large-fire growth. The purpose was to
put together a data set suitable for analyzing large-fire
growth. Of particular importance to further study are growth
progression, rates of spread, and relation of fire progress
to weather and terrain.

The growth of the 1988 fires in the Greater Yellowstone Area
from July 14 to October 1 is represented in the form of daily
fire perimeter maps. Major fires included in the dataset are
the North Fork-Wolf Lake, Fan, Hellroaring, Storm Creek,
Clover-Mist, Huck, Mink, and the Snake Complex, consisting of
the Falls, Red, and Shoshone Fires. This fire record
integrates information and data from a variety of sources,
including daily infrared photography flights, satellite
imagery, ground and aerial reconnaissance, command center
intelligence, and the personal recollections of fire behavior
observers. Using GRASS GIS software, fire position was
digitized from topographic maps to construct a file of daily
fire location in vector format. The fire perimeter layer
contains polygons made up of perimeters representing the fire
position, each with a single attribute of date. The major
fire the polygon belongs to is also identified. Large
unburned areas within the fires' perimeters were excluded
when possible, but the fires burned as mosaics and many small
patches of unburned vegetation could not be identified or
excluded. Thus the area within the final perimeter will
overpredict the actual area burned.

One of the key elements of this work has been a comprehensive effort to
resolve conflicting or incomplete data and to develop maps accurately
depicting the growth of the fires. Considerable thought and care were
given to preparation of the fire perimeter map, but there are many
potential sources of error; the data should not be considered to be the
absolute truth. Boundaries, streams, and sites used for reference at map
production scales were taken from a variety of sources and were digitized
at a variety of scales. These results should not be considered for
determining legal questions such as whether or when a fire burned a
particular feature. Two aircrafts (with infrared scanners) were available
until late August, when one was sent to other fires. Unfortunately, the
largest fire growth was taking place at this time, and one aircraft
could not cover all of the active fire perimeter in one night of flying.
Areas on the Snake Complex in the south, the Clover-Mist Fire in the
eastern section, and the North Fork-Wolf Lake Fire were not well mapped
late in the summer.