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Wildfire Simulation Technology – Part 2

In the summer of 2003, a wildfire was threatening the Montana town of Hungry Horse. Several simulations were run by scientists who had combined data on the conditions of the fire, fuel, and weather to provide a forecast of what the fire would do.

The results of one of these simulations suggested that some spot fires could occur on the far side of Hungry Horse Reservoir. Firefighters were waiting when that occurred, quickly dousing the blazes. Instead of a conflagration that could have consumed thousands of acres, it was contained after scorching just 20 acres, sparing Hungry Horse and some key power lines in the fire’s path in the bargain.

Since that time, wildfire simulations have improved and multiplied considerably. With an estimated 40% of homes in the U.S. in the Wildland Urban Interface, even major cities need to have ways to predict wildfire activity. In this installment of our series on wildfire simulations, we will sample some of the more advanced software available to deal with wildfires worldwide developed by federal agencies and, in most cases, available as a free download.

U.S. Forest Service

U.S. Forest Service (USFS) scientists have a number of software tools that can be utilized to analyze and model wildfire behavior. But in order to properly use these tools, a bit of classwork is required, which falls under the aegis of the Geospatial Fire Analysis Interpretation and Application course, generally know by its catalog designation, S495. “This is an intense course whose intention is to train individuals to use several different decision support systems that fire managers use to model/simulate fire growth and fire behavior characteristics,” explained Chuck McHugh, a USFS Fire Spatial Analyst who does behavior modeling for wildland fire at the Rocky Mountain Research Station, Fire Sciences Laboratory in Missoula, MT. “It requires approximately 120-160 hours of distance learning material, and then 40 hours of residence (classroom) instruction.”

Users also need a solid foundation in understanding fire behavior to adequately assess the validity of modeling results. In order to attend the S495 course, applicants also have to have successfully completed S490 – Advanced Fire Behavior Calculations.

“During S495, students learn to use FireFamilyPlus to analyze historical weather,” said McHugh. “They also get a heavy dose of training in Geographic Information Systems (GIS) to analyze, critique, and edit geospatial data, and they are taught how to use several different fire modeling systems: FARSITE, FlamMap, and FSPro.”

Let’s take a closer look at the programs McHugh mentions.

FireFamilyPlus (FFP) is used for summarizing and analyzing daily weather observations and computing fire danger indices based on the United States National Fire Danger Rating System (NFDRS). It will also produce Fire Danger Indices for the Canadian Fire Danger Rating System (CFDRS). The guide that comes as part of the download provides details on obtaining historical fire weather and occurrence data, importing those data into FFP, and working with the analysis capabilities of the program. The nice thing about this program is that it can be downloaded to a personal computer for use anywhere. For more information, go to http://www.firemodels.org/index.php/national-systems/firefamilyplus.

FarSite is a fire behavior and fire growth simulator that incorporates both spatial and temporal information on topography, fuels, and weather. It incorporates existing models for surface fire, crown fire, spotting, post-frontal combustion, and fire acceleration into a two-dimensional fire growth model. This software is used by the USFS, National Park Service, and other federal and state land management agencies to simulate the spread of wildfires and fire use for resource benefit across the landscape. And best of all, it can be downloaded free to a personal computer! Visit http://www.firemodels.org/index.php/national-systems/farsite to get more information on this software.

FlamMap is a fire behavior mapping and analysis program that computes potential fire behavior characteristics (spread rate, flame length, fireline intensity, etc.) over a landscape under constant weather and fuel moisture conditions. This software creates digital maps of potential fire behavior characteristics like spread rate, flame length, and crown fire activity, for given environmental conditions (dead-fuel moistures, mid-flame wind speeds, and solar irradiance). These digital maps (which can include fire perimeters, fire behavior characteristics, and information regarding fuel moistures used during the simulation) can be viewed in FlamMap or exported for use in a GIS programs like ArcMap, as images, or to a word processor program (all of which would be handy for sharing with interested parties during an incident). As with FarSite, FlamMap can be downloaded to a personal computer for free. More information is available at http://www.firemodels.org/index.php/national-systems/flammap.

FSPro [Fire Spread Probability] is a different fire modeling system and is contained within the Wildland Fire Decision Support System (WFDSS),” explained McHugh. “Unlike the others, which you can install and run on a laptop or desktop computer, FSPro cannot.”

Also the output from the FSPro model is much different than the previously mentioned decision support system. “Rather than representation of fire growth, FSPro produces a probability surface that offers information about the probability of a fire reaching or impacting a point of concern within the specific time frame used for the simulation,” said McHugh. This probability surface can then be intersected with values of concern such as structures, powerlines or critical wildlife habitat, thus allowing for a true risk-based decision-making process. “It is very computationally intensive and utilizes very fast computers that are centrally located along with all the data required to run the model. Access to this system is limited and it is used to help in the decision-making process of real-time fires,” he added. To learn more about FSPro and WFDSS, visit the USFS website at https://wfdss.usgs.gov/wfdss/WFDSS_Home.shtml.

LandFire is the crucial “silent partner” in making these fire simulations possible. “We’re highly dependent on LandFire data for all the simulations we do, and the quality of the LandFire data is improving with each generation,” McHugh confirmed. “It provides seamless, consistent data layers, including fuel types, fire regime classification, and other geospatial layers of data critical to using geospatial decision support systems, such as FarSite, FlamMap, and FSPro.” Anybody can access LandFire data at http://www.landfire.gov.

And although these simulations are as realistic as software modelers can make them, there is still room for improvement. “Fire models don’t provide detailed information or ‘the answer,’ but rather information for the decision-maker to make a more informed decision. However, this does not mean that at times we will not have informed failure,” McHugh said, with a cautionary quote from George Box, “All models are wrong, but some are useful.

The picture wouldn’t be complete, however, without adding a couple of additional programs.

WindNinja simulates wind across the landscape using flow dynamics engineering that creates what you’d expect wind to do,” said Laurie Kurth, a Fire Applications Specialist in the Wildland Fire Management Research Development & Application group at Rocky Mountain Research Station, who leads the development of training for use in the S495 training program. “We also have a unit within the course for working with ArcMap.”

If you are interested in finding out more about how the S495 program can help you understand these advanced modeling tools, go to http://frames.nbii.gov/portal/server.pt/community/fire_behavior/212/s-495/2840.

Canada

With an average of 8,000 fires per year, costing between $500 million and $1 billion to extinguish, Canada has also been active in developing wildfire prediction software. Their answer to this problem is Prometheus, a deterministic wildland fire growth simulation model based on the Fire Weather Index (FWI) and Fire Behaviour Prediction (FBP) sub-systems of the Canadian Forest Fire Danger Rating System (CFFDRS). It produces a GIS model that contains spatially explicit fire behavior and spread outputs given heterogeneous forest fuel, topography and weather conditions. Fuel types and weather can be modified by users to evaluate a variety of scenarios and the data inputs can be imported from files or created manually.

Not only can Prometheus provide operational decision support by predicting wildfire behavior, users can also conduct “what-if” scenarios to determine the threat of potential wildfires to values at risk; it can assist in setting up fire management zones, and identifying opportunities for the use of prescribed fire; and supplement wildfire training and education programs, among other uses.

As with many of the USFS programs, Prometheus can be loaded onto a personal computer for use in the field or command post applications. The requirements for a computer to be able to run this modeling software fall within the parameters of most laptops/desktops and can be seen at http://firegrowthmodel.ca/requirements.html.

For more information on this software, visit http://www.firegrowthmodel.com.

Australia

The U.S. and Canada aren’t the only countries doing wildfire simulation research. CSIRO (Commonwealth Scientific and Industrial Research Organisation) is Australia's largest public research organization. It conducts strategic research in a wide range of areas, including bushfire simulations.

SiroFire, “The CSIRO Bushfire Spread Simulator,” was created by CSIRO’s former Bushfire Behaviour and Management Group (http://www.csiro.au/solutions/SiroFire-Overview.html) as a PC-based decision support application designed to assist fire controllers in predicting the likely spread of a fire under forecast weather conditions. Launched in 1994, SiroFire uses information such as temperature, relative humidity, wind speed and direction, fuel load and conditions, grass curing, slope, and the selected fire spread model to predict the spread of a bushfire and plot the perimeter on a map of the area of interest. Instead of performing laborious calculations with slide rules and plotting results manually on a map, fire controllers can use this system to perform the same task in seconds. Although primarily developed for use as an operation tool for real-world situations, a bonus of the software is that it can also be used for training and simulation.

But CSIRO doesn’t stop there. They also field a number of free computer programs for bushfire prediction and management, including:

  • McArthur MK 5 Forest Fire Danger Meter is assisting rural fire authorities across Australia. You can download an 855 KB zip file to use the CSIRO McArthur MK 5 Forest Fire Danger Meter as a computer program. To see more information and download a copy of McArthur, go to http://www.csiro.au/products/McArthur-Fire-Danger-Meter-Download.html.
  • CSIRO Fire Danger and Fire Spread Calculator is a computer program available as a 943 Kb zip file that can be downloaded for use in assisting rural fire authorities across Australia. Go to http://www.csiro.au/products/Fire-Danger-And-Spread-Calculator.html for more information and a downloadable file.
  • Grassland Fire Danger Meter is used by rural fire authorities to predict the risk of grassland fires. Go to http://www.csiro.au/products/Grass-Fire-Danger-Meter.html for more info.
  • CSIRO Grassland Fire Spread Meter is used by rural fire authorities to predict a fire’s potential rate of forward spread across continuous grassland in gently undulating terrain. More information can be found at http://www.csiro.au/products/GrassFireSpreadMeter.html.
  • CSIRO House Survival Meter provides homeowners with a guide to the probability of a house surviving a bushfire based on six important factors. More information can be found at http://www.csiro.au/products/HouseSurvivalMeter.html.
  • CSIRO Fire Spread Meter for Northern Australia predicts the rate of spread of fires in open grassland, woodland, and open forest with a grassy understory. Further information can be obtained at http://www.csiro.au/products/NthAustFireSpreadMeter.html.

For an overview of all of these products, go to http://www.csiro.au/science/Bushfires/Business--group-Product.html.

As can be seen from the preceding information, many software tools to help fire managers are available from various agencies. These agencies are not resting on their laurels, however, and new software will become available in the future, so it is wise to check in on the websites given above from time to time. Who knows, the next innovation may save your bacon (and someone’s home) the next time wildfires come calling!

MIKE ARCHER is an author, wildfire consultant, systems engineer, and public speaker who has been interviewed by CBS News, KABC-TV, USA Today, and the Associated Press on wildfire topics, and has been part of a delegation testifying before government bodies (including Congress and the California Senate) on fire-related issues. He runs the Wildfire News of the Day blog and Firebomber Publications.

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