Simulation tools to predict
wildfire behavior and to help
safety decision making
Marc Castellnou and Bruce Schubert
• Marc Castellnou, Fire Chief, Catalonia Fire Service
• Pau Costa Foundation, President
• Fire Behavior Analyst, GRAF
• Bruce Schubert, Owner, Emxsys
• Emxsys: Emergency Management Expert Systems
• Software Architect and Developer
If we want to use simulations and analysis of wildfires,
we can try:
• Numerical Simulation: Rothermel model in Missoula, Montana - BEHAVE
• Logical Simulation: Based in empirical firefighter knowledge, Doug Campbell
in USA and Marc Castellnou in Spain - CPS
• GIS Simulation: To show numerical models over maps and look for
correlations and have a better understanding with spatial analysis - FARSITE,
FLAMMAP
• Potential Simulation: Mix of logic, numeric and GIS, looking for chaotic and
random ocurrence to identify PATTERNS of behavior - WFA
The Huygens principle
Used in all wildfire GIS
simulations
Minimum Travel Time or Fire Paths
• Connection of ellipses are identified as „supposed fire paths‟
So.....
• Huygens principle of calculation makes one assumption: The fire spread is a
row of ellipses, and that’s the fire path.
• Minimum travel time (MTT) shows the fastest fire paths. Its an initial approach
to identifying major runs.
But......
• Reality shows us that fire moves using runs.
• Those runs start, grow, die, and then resume when the fire has alignments to
produce another run.
• Watch the video........................
WHY a new approach?
Fire simulation
doesen‟t actually
reflect how fire
moves
“Fire runs” or “fire
paths” can be
infered using MTT
adjustments - a
well used
technique in
wildfire analysis
today
However, this
method of
simulation doesn‟t
allow planning for
unpredictable
events.
Everything is
connected to the
initial assumptions
Unpredictable fire
behavior is linked
to long distance
spotting and fire
storms
Fire moves over
landscape fast
and erratically but
maintains the
physic principles
of radiation and
convection that
compose a fire
run
We need to
simulate real runs
possible over an
incident scenario
so we can plan for
the expected and
the unexpected
The standard approach for the unpredictable....
A probabilistic simulation:
• Thousands of simulations
using a variation of all data –
for example: wind +/- 25%,
humidity +/- 30 % etc...
• We can see the chances of
the fire spreading as
predicted, and what the
chances are of it doing
different things if the situation
becomes unpredictable.
How can we predict the unexpected?
• By not looking at just one single fire event
• By not complementing a single fire event simulation with a deterministic and
statistical aproach of multi-simulation
We try to fill the unpredictable gap using:
• Alignment concept to focus on the fire run getting worse or better
• Models to create identified fire behavior for every single fire run
• Random and chaotic ignitions to look for unpredictable events
• Mapping over 3D terrain to show the flux of runs
• Concentrate on looking for highways of fire over the landscape
• Create a tool that can show how these highways change when the
environment changes
New Vision
• We don‟t look a fire spreading, we don‟t look to GIS layers of fire
behavior....
• We improve the CPS fire path concept and bring it to a new level:
• Concentration of paths: highways
• Lack of paths: windows of opportunity
• Identification of new highways mapped when situations change
• Identification of slowing down areas that break highways: good for safety
and opportunity of operations
• When we look at the landscape, we look at the predictable and
unpredictable fire runs, not just the ones that we can see but also the ones
we don‟t see now--but could happen.
HOW TO READ THE MAPS WE ARE CREATING:
Big density of
runs area
Big density of
runs area
Target operation
sites to break
connections
Low density of
runs area
Polygons where
no Areas
runs happen,
identified
present
windows of
as a windows
of opportunity
opportunity to
to
stop
firespread
spread
stop
HOW TO READ THE MAPS WE ARE CREATING:
Highway of fire runs,
axis of spread of any
fire happening in this
landscape under this
condition
New highways
Almost all area have changed from fire that we can attack, to fire over our
threshold of control. Almost all slopes are burning extreme. Highways still stay
Highway of extreme behavior that is showing windows of opportunity after a while.
Those yellow breaks of high intensity are windows of heaven for firefighters inside the storm: