Justin Peglow
Geog 370
Lab 7: Lab Report Write-Up
This lab was designed to designate the level of fire hazard potential for the area
within the extent of Glacier National Park, Montana. Calculations to assess this were
based on a number of different factors that are known to contribute to increasing the fuel
load of vegetative biomass. Fuel load variation is the number one determinant of the fire
risk of an area, with low fuel loads having low fire hazard and high fuel loads having
high fire hazard. Maps of the risk of each of these factors were created, then compiled
together to create a final composite map showing the relative areas of low, medium, and
high fire hazard for the entire park.
Factors contributing to fire fuel load for vegetation are NDVI value, land cover
type, slope gradient, slope aspect, and area proximity to hiking trails and bodies of water.
Using LANDSAT maps for NDVI values within the park, calculations were made to
separate areas of high NDVI value (high fire hazard) from areas of low NDVI value (low
fire hazard). Areas with land cover types associated with high fire fuel potential were also
segregated from areas with land cover types associated with low fire fuel potential. With
the dominant wind in the park coming out of the southwest and because winds accelerate
forest fires, all slopes facing southwest were also labeled as high fire hazard potential. All
other directions were not significant in increasing fire fuel load, and designated as having
low fire potential. Also, the same elevation map that was used to calculate slope direction
was utilized to find gradients of greater than 35 degrees, which were then designated as
sites of high fire fuel potential since fires spread quickly up steep slopes. A buffer zone
out to 150 meters from a hiking trail through the center of the park is considered to be of
high fire hazard potential. Major bodies of water were located, and a buffer zone out to
Justin Peglow
Geog 370
500 meters from the edges of these locations was created on a map. Within this buffer
zone, moisture levels were high in comparison with the rest of the terrain in the park, and
were labeled as areas that diminish fire fuel loads. For each map, the relative fire fuel
potential was calculated, with areas of low fire hazard concern having a value of “0” and
high fire hazard concern having a value of “1”. Since each of these maps contained
roughly the same spatial extent and resolution of the park, they were easily added
together to create one overall fire hazard map, with fire potential values ranging from 0
(lowest) to 7 (highest). An example of an area of high fire hazard is one that faces
southwest, has a high NDVI value, has a steep slope gradient, etc. Conversely, an area of
low fire hazard is one that faces east, is within 500 m of a body of water, has low fire fuel
land cover type, etc.
The results of the final map shows that the area within Glacier National Park is
approximately one-third high fire hazard, one-third medium fire hazard, and one-third
low fire hazard. This shows that each fire hazard category contains an equal amount of
land in the park; however spatial variations and distributions vary greatly. Areas of low
fire hazard are mainly concentrated around a large lake on the eastern side of the park,
and around all other bodies of water that generally surround the proximity of the park in
the northeast and southwest borders. Conversely, most areas of high fire hazard are
mostly centered around areas containing high NDVI values, dense standing biomass, and
high fire hazard land types. These areas mainly make up the center of the map (slightly
offset southwest) and take up most of the northwest and southeast regions of the park.
Medium fire hazard areas are interspersed in between the high and low fire hazard areas,
revealing the fairly steady gradation that usually occurs between hazard ratings and land
Justin Peglow
Geog 370
type. Nonetheless, the areas of medium fire hazard are mostly concentrated on steep
slopes.
Conclusions can be drawn from the results that expose strong correlations and
relationships among each factor determining fire fuel load potential. Since most high fire
hazard areas are almost all completely related to status and type of vegetation, it is
probably the primary factor leading to an area of high fire potentiality. Areas of high
moisture content, clearly greatest around bodies of water, contain no highly flammable
vegetation types and predominantly exhibit the lowest fire hazard. Steep slopes are
mostly areas of medium fire potential; although they present a fire hazard, their rating is
lower than flatter regions of terrain most likely because high standing biomass and dense
high fire fuel load vegetation types do not grow well on sharp gradients. The map shows
that areas around the trail not near the largest lake (which borders a portion of the trail to
the south), especially near the center of the park, have high fire hazard, and are
potentially dangerous to recreational campers and hikers.
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