Start a new topic
Answered

Scale limitations on fire behavior model?

Is there a minimum recommended analysis area size for fire modeling in IFTDSS? I'm wondering if the tool would be appropriate for small forested preserves less than 1000 acres in size.


Best Answer

Great Question Brian. 


The underlying data source for IFTDSS Fuels information is LANDFIRE. (www.LANDFIRE.gov).  LANDFIRE data are pixels at 30 m resolution. The LANDFIRE team recommends a minimum analysis area of at least 5 acres or approximately 22 pixels at 30 m resolution.  This reference provides a little more background information on this topic and recommendations for field validation of the data. https://www.landfire.gov/documents/EvaluatingLANDFIREFuelsData.pdf    IFTDSS does provide functionality to "edit" your initial landscape if your local expertise determines that the LANDFIRE Fuel Model mapping does not accurately portray conditions.  


In terms of the Fire Behavior Analysis, the outputs are also at a 30m resolution and directly tied to the Fuels Layer in terms of the outputs.  Currently, only the FLAMMAP Basic Model is in IFTDSS so keep in mind that the outputs for this model are independent at the pixel level and do not model spread from pixel to pixel.  In other words, the outputs for each pixel are independent and based primarily on the Fuel Model Classification in the LANDFIRE data. 


So this is a detailed answer to say that "yes", the tool would be appropriate at small preserve sizes well below 1000 acres in size.  It would be prudent to take a good look at how the Fuels have been classified and then whether the model outputs in terms of flame length, rate of spread, etc.  for that fuel model and given weather input match what you would expect based on your knowledge of these areas. 


Hope this is helpful and thanks for the question.




Thanks! That's extremely helpful, especially the part about FLAMMAP being pixel-independent.

Answer

Great Question Brian. 


The underlying data source for IFTDSS Fuels information is LANDFIRE. (www.LANDFIRE.gov).  LANDFIRE data are pixels at 30 m resolution. The LANDFIRE team recommends a minimum analysis area of at least 5 acres or approximately 22 pixels at 30 m resolution.  This reference provides a little more background information on this topic and recommendations for field validation of the data. https://www.landfire.gov/documents/EvaluatingLANDFIREFuelsData.pdf    IFTDSS does provide functionality to "edit" your initial landscape if your local expertise determines that the LANDFIRE Fuel Model mapping does not accurately portray conditions.  


In terms of the Fire Behavior Analysis, the outputs are also at a 30m resolution and directly tied to the Fuels Layer in terms of the outputs.  Currently, only the FLAMMAP Basic Model is in IFTDSS so keep in mind that the outputs for this model are independent at the pixel level and do not model spread from pixel to pixel.  In other words, the outputs for each pixel are independent and based primarily on the Fuel Model Classification in the LANDFIRE data. 


So this is a detailed answer to say that "yes", the tool would be appropriate at small preserve sizes well below 1000 acres in size.  It would be prudent to take a good look at how the Fuels have been classified and then whether the model outputs in terms of flame length, rate of spread, etc.  for that fuel model and given weather input match what you would expect based on your knowledge of these areas. 


Hope this is helpful and thanks for the question.




1 person likes this
Login or Signup to post a comment