Custom Fuel Model File (.FMD)

This is a optional ASCII text file for FARSITE.

The use of custom fuel models is supported in FARSITE. Models other than the standard 13 Fire Behavior models (Anderson 1982) must be supplied in a Custom Fuel Model (.FMD) File.

FARSITE 4.0 allows fuel model inputs in English or metric units. The units are selected by inserting the word ENGLISH or METRIC as the first line of the Custom Fuel Model (.FMD) File. If no option is found FARSITE defaults to English units.

Each Custom Fuel Model (.FMD) File must contain data in the space delimited ASCII format specified below. FARSITE has a Custom Fuel Model Editor (see below) to help you create or edit Custom Fuel Model (.FMD) Files. Or, a generic text editing application such as Notepad or WordPad, a spreadsheet, or the FARSITE Editor can be used to create or edit ASCII text files. The Custom Fuel Model (.FMD) File must be in the following space delimited format, and have fuel model numbers between 14 and 50.

FMod 1H 10H 100H LiveH LiveW 1HSAV LiveHSAV LiveWSAV Depth XtMoist DHt LHt

Sample .FMD file

ENGLISH
19 2.250 1.500 3.710 0.000 1.000 2000 1800 1500 0.600 25 8000 8000

Using the Custom Fuel Model Custom Editor

The Custom Fuel Model (.FMD) File Custom Editor is accessed through the "FARSITE Project" dialog box. The button to the right of the Custom Fuel Model (.FMD) File text box brings up the custom editor for generating or editing a Custom Fuel Model (.FMD) File.

Editing an Existing Custom Fuel Model File

If you currently have a Custom Fuel Model (.FMD) File loaded, this dialog box will allow you to edit the contents of that file. Only custom fuel models can be edited, the standard 13 Fire Behavior models cannot.

The Custom Editor allows direct editing in the text box by selecting text with the cursor, using the backspace key, and typing text similar to a text editor.

Testing Fuel Models

The Custom Fuel Model Editor can also test individual fuel models similar to a mini BehavePlus. First select a fuel model to test, wind, and slope in the spin boxes. Then select a low, moderate, or high fuel moisture scenario (the moisture values used for each scenario are shown below the radio buttons). Click the Calculate button to see the rate of spread, flame length, and critical crown base height.

Tuning Custom Fuel Models

You can also tune individual custom fuel models by changing the fuel model parameters to modify the predicted fire behavior. Wind, slope, and fuel moistures are entered as when testing (see above).

Select a tuning ratio in the Tuning spin box to see the effect on rate of spread, flame length, and critical crown base height. Test the tuning ratio for the three fuel moisture scenarios and over a range of winds and slopes. Clicking the Apply button will change the fuel model parameters to match the effect of the tuning ratio.

Using the tuning feature actually changes the fuel model so all fire behavior parameters, heat per unit area, fire intensity, etc. are changed. When using an Adjustment Factor (.ADJ) File only the rates of spread are modified.

Create a New Custom Fuel Model File

To generate a new Custom Fuel Model (.FMD) File click the New Model button. The following dialog box appears where you select a number for your new model and an existing model to base the new fuel model on.

The new fuel model is displayed in the custom editor text box to be edited, tested, or tuned as shown above.

Finally

For each custom fuel model, you must specify an initial fuel moisture in the Fuel Moisture (.FMS) File AND an adjustment factor in the Adjustment Factor (.ADJ) File.

Before clicking the Apply & Exit button make sure the modified file has been saved with the Save .FMD File button. If you don't save the changes, they will still be in effect for the current simulation, but they will be lost when the simulation is terminated. However if the Project (.FPJ) File is saved with an unsaved edited Custom Fuel Model (.FMD) File, the Custom Fuel Model (.FMD) File will then be automatically saved also.