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.

Areas identified

as a windows of

opportunity to

stop spread

Big density of

runs area

Low density of

runs area

Big density of

runs area

Target operation

sites to break

connections

Polygons where

no runs happen,

present windows

of opportunity to

stop fire spread

HOW TO READ THE MAPS WE ARE CREATING:

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

under control.

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:

Safety.

They also identify areas where to perform fuel management during calm periods without fire. Cool.