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F.O.F.E.M. 5First Order Fire Effects Module
Adapted from:Missoula Fire Sciences Laboratory
Systems for Environmental Management
• “First-order effects” are the immediate consequences of a fire.
• Second-order effects??– Longer term effects– Involve interaction with other agents
• Vegetation dynamics, insect-caused mortality, climate and weather, erosion– Examples: Tree regeneration, plant succession, site productivity
Fuel consumptionSmoke production
Tree mortalitySoil heating
What is a “first-order” effect?
FOFEM 5 is used to…
Quantify Fire Effects (Severity) vs. Fire Behavior (Intensity).
• Assess wildfire and prescribed fire impacts.– Ex. how many trees can we expect to survive?– Ex. how many centimeters of soil were exposed to lethal
temperatures?
• Predict the effects of a current fire.– Ex. How much smoke will be produced?
• Design fire and silvicultural prescriptions.– Ex. Under what moisture conditions can we reduce duff by 30%?– Ex. How many acres can burn without exceeding particulate
limits?
How FOFEM works
• FOFEM compiles fire effects data and models from the literature.
• FOFEM 5 automatically uses the best available equation or model.
• Creates default inputs for vegetation and fuel types – so the user doesn’t have to collect data.
FOFEM 5: Tree mortality
• By species and size• 207 tree species• Estimates bark thickness from species and
diameter. • Predicts mortality from bark thickness, crown
scorch.• Mortality algorithm does not account for:
– season of burn, post-burn insect attack, drought, or resid. time
Tree mortality: inputs
Set fire severityChoose region
Define tree list
Set fire intensity
Select “mortality”
Tree mortality: outputs
PROBABILITY OF MORTALITY FOR EACH SPECIES/DIAMETER
Species Diameter Number Prob Mort Equ Code (inch) Trees Mort Number _____________________________________________
PSEMEN 1 300 1.00 1 PSEMEN 8 100 0.39 1 PINPON 20 25 0.07 1
STAND TREE MORTALITYPercent mortality: 49 Number of trees killed by the fire: 341Average tree diameter of firekilled trees: 1.9 Percent mortality for trees 4+ in DBH: 23 Total prefire number of trees: 425
FOFEM 5: Fuel consumption
• Inputs needed:– Fuel load by size class
(1,10,100,1000 hr fuels, etc.)
– Fuel moisture
• Outputs generated:– Fuel consumption by size
class– Post-burn fuel load
Fuel Consumption: inputs
• Fuel load
Select region & classifica-tionSelect
cover type
Select fuel category
Set fuel load adjustments
Select “Fuel”
Fuel Consumption: inputs
• Fuel load
Set percent 3”+ load that is rotten
Set percent crown fuel burned
Set season of burn
– Or you can input fuel load data directly.
Fuel Consumption: inputs
• Fuel moisture– Moisture condition (very dry, dry, moderate, wet)Choose
moisture condition
Or, you can input fuel moisture directly
Fuel Consumption: outputs
• Graph and report of pre-burn and post-burn fuel data.
Fuel Graph
Preburn Load Consumed Load Remaing Load
0
20
10
30+
tons
Litter 0-1/4 1/4-1 1-3 3+ Duff Herb Shrub Foliage Branch
FOFEM 5: Smoke production
• Predicts emission production rate.
• Gives proportion of flaming versus smoldering combustion
• Estimates production of:– PM10: affects visibility– PM2.5: trapped in human lungs
– CO2, CH4, NOx, SOx, CO: greenhouse gases
FOFEM 5: Smoke production
• Inputs needed:– Fuel load by size class– Fuel moisture– (Same as fuel consumption)
• Outputs generated:– Smoke production over time
for each emission molecule– Flaming and smoldering
combustion
Select “Smoke”
Smoke emissions: outputs
• Graph and tabular report of smoke production by component.
FOFEM 5: Soil heating
• Soil heating model:– predicts time,
temperature, depth profiles
Soil heating: inputs
• Soil heating inputs are the same as fuel consumption, with two additions…
Select “Soil”
Choose soil texture
Set soil moisture content (percent)
Soil heating: outputs
• Graph and tabular report of soil heating by depth.
25
50
75
100
0
Temperature
(C)50 100 150 200 250 300 350 400 450 500minutes
Max Tmp: 61(c) Post Fire Duff Depth: 1.31(in) Soil Moist:10.00% Type:Coarse-LoamLines represent temperatures at 1 centimeter intervals, starting at soil surface.
Soil Heating
FOFEM 5: Strengths
• Simple, easy to learn and use.
• Can be used for a variety of purposes.
• Accommodates variable level of input detail.
• Combines physical and empirical models from scientific research.
• Creates reports, graphs and data tables that can be incorporated into other documents, including GIS.
FOFEM: Weaknesses
• Outputs are only as good as the algorithms and default data in the fire literature.– Some defaults are only based on 2-3 studies– Some inputs are general (ex. moisture = low, medium,
high).
• Assumes a continuous, complete burn (not patchy), so it may overestimate the effects.
• Does not estimate second order effects (ecological interactions)
• Forest-centric – only a few grass and shrub models