 South
Canyon Fire
1994
Fire Behavior Report, 1998
Fire Environment
- July 2 to
Evening of July 5
- July
5, 2230 to July 6, 1530
- July 6, 1530
to 1600
- July 6, 1600
to 1603
- July
6, 1603 to 1609
- July 6, 1609
to 1610
- July 6, 1610
to 1611
- July 6, 1611
to 1614
- July 6, 1614
to 1623
- July
6, 1622 to 1830
- July
6, 1830 to July 11
References
Appendix A
Appendix B
Appendix C
|
 Fire
Behavior Associated with the 1994 South Canyon Fire on Storm King Mountain,
Colorado
Fire Environment
Fuels
Vegetation in the area consisted primarily of Gambel oak (Quercus
gambelii) on the north- and west-facing slopes and open, mixed pinyon-juniper
(Pinus edulis and Juniperus sp.) with a cured grass
understory on the south-, southwest-, and east-facing slopes. A few “pockets”
of Douglas-fir (Pseudotsuga menziesii) existed in the area of
the Double Draws, the Bowl, and on the lower east-facing slope of the
West Drainage. Continuous cured grasses and some shrubs and small stands
of pinyon-juniper covered the bottom of the north-south oriented West
Drainage (Anon 1994). The Bowl contained a heavier concentration of grasses,
mixed shrubs, woody debris, and trees. Figure 9 shows the approximate
distribution of the vegetation over the fire site.
The Gambel oak was more than 50 years old and did not contain much dead
material (South Canyon Report; Biastoch 1995). It formed a dense, green,
continuous closed canopy, 6 to 12 feet tall and appeared to be unaffected
by spring frosts (fig. 10). Visibility within the stand was limited. The
surface fuels beneath the canopy consisted of a 3 to 6 inch layer of leaf
litter (Husari 1996).
Figure 9—Drawing showing approximate distribution of vegetation
in area of South Canyon Fire. Perspective is looking northeast across
West Drainage from location over Colorado River (adapted from Accident
Investigation Report, not to scale).
Fine dead fuel moisture content was estimated to range from 2 to 5 percent
on the afternoon of July 6 (South Canyon Report). Both the large diameter(1000
hour) dead fuels and the live fuel moisture contents in the area were
several weeks ahead of their historical summer drying trends (South Canyon
Report). No fuel moisture content samples were collected at the time of
the fire. However, live foliar moisture contents were measured on July
12, 1994, at a site near the South Canyon Fire with an aspect and elevation
similar to the west flank of the Main Ridge. Foliar moisture in underburned
Gambel oak was about 60 percent while that in green unburned Gambel oak
was 125 percent (South Canyon Report). Typically, live fuel moisture levels
change relatively slowly in undamaged shrubs. Therefore, we expect the
foliar moisture content of the unburned Gambel oak on July 6 would have
been similar to the values measured on July 12. No samples were collected
in the pinyon-juniper fuels.
Figure 10—Photograph of Gambel oak at South Canyon Fire Site taken
on July 6, 1994. Note lack of significant amount of dead leaves and stems
in the canopy. Courtesy
of T. Petrilli
<<< continue reading—Fire
Behavior at South Canyon Fire, Fire Environment - Weather >>>
|
