Risk: Convert FLPs

A Flame Length Probability File (FLP) is a gridded text file that contains information about burn probability and fire intensity for each point. Fire intensity is expressed as Fire Intensity Level (FIL) classes. Each FIL is related to flame length classes (they differ for Metric and English FLPs, more below). The sum value of the FIL categories is 1, where the value within each FIL is the probability of the fire burning at that intensity.The FLP file is also referred to as the conditional flame intensity file, because it includes information on the intensity of any point on the landscape, given a fire occurs.

• FLP - 20 Bin Metric: Each of the 20 FIL is representative of a 0.5 m increment, so FIL1 is 0-0.5 m, FIL2 is 0.5-1 m, and FIL20 is >9.5 m.
  • In ArcFuels you have the option of defining value of the largest FIL for calculations. The default is 9.75 m.

• FLP - 6 Bin English: FIL1 is 0-2 ft, FIL2 is 2-4 ft, FIL3 is 4-6 ft, FIL4 is 6-8 ft, FIL5 is 8-12 ft, and FIL6 is >12 ft.
  • In ArcFuels you have the option of defining value of the largest FIL for calculations. The default is 20 ft.

Example of converted FLP shapefile attributes table (A) and shapefile (B) for an FLP with 20 FILs.

Conditional flame length (CFL) is the probability-weighted flame length given a fire occurs, and is a measure of wildfire hazard. It can be calculated during the conversion of the FLP file(s). The formula to calculate CFL is:

CFL = ∑ (BPi) (Fi)

where BPi is the probability of a fire at the ith flame length category (the FIL value) and Fi is the flame length midpoint of the ith FIL category (i.e., for the 20 bin Metric FLP 0.25 m, 0.75 m, etc.).

The Convert FLPs form combines multiple ArcGIS steps into one:

1. Adds the XY data as an events file, then exports the data as a shapefile while defining the projection (appended with_FLP),
2. Calculated the conditional flame length, and appends this to the shapefile attributes
3. Creates a burn probability raster (appended with _BP)
4. Creates rasters for each flame length intensity level (appended with the level, i.e. _1, _2)
5. Creates a conditional flame length raster (appended with _CFL)

Input File is the FLP text file to be converted.

Outputs:

• You can convert the FLP to a FLP point shapefile, FIL rasters, BP raster, and CFL raster.
  • The FLP point shapefile is used to complete Net Value Change and Expected Impacts calculations, and do Summary Statistics.
  • The FIL, BP and CFL rasters are rasters of all the fields within the FLP file.
• The Flame length to use for FIL6/FIL20 allows you to set the value for the highest FIL category.
  • The default for a FLP - 6 Bin English is 6 ft.
  • The default for a LP - 20 Bin Metric is 9.75 m.
• The Outputs base name must be less than 10 characters, does not start with a number, has no spaces, and has no special characters with the exception of an underscore.
• The Spatial reference is set using the drop-down list.
• The Cell size is the same as was used in the wildfire simulations.
• The Output format of the rasters can be Individual items, or Geodatabase
  • Individual items are output in the Target Folder. The default is the output folder specified when setting up a project in the Project Settings form.
  • Rasters output into a Geodatabase require the path and name of the Geodatabase and the Work folder. The default location of the Work folder is the same as the Target folder.

The Batch Convert FLPs form has the same functionality as the Convert FLPs form with the added benefit of converting multiple files at once.

The Source Folder is the path to the FLPs to be converted.

Exercise 24—Converting a single FLP

In this exercise, you will convert a single FLP file output from FlamMap5, into a projected point shapefile. The FLP is from a run completed at 90 m resolution for the entire Mt. Emily landscape.

Click the Risk button on the ArcFuels10 toolbar, then select Convert FLPs from the drop-down list.

Fill out the Convert FLP form following the figure below.

• Click the OK button.
• A progress meter will open tracking the conversion progress.
• A window will open indicating how many of the files were converted. Click the OK button to close the window.

Return to ArcMap.

• The newly created shapefile and rasters has been put under a new grouping, Conversion Results.
• Look at the different layers created to familiarize yourself with the outputs.

Converted files from the FLP for the Mt. Emily project area. The raster displayed is the FIL2 which represents the probability (0 to 1) of a flame length between 0.5 and 1.0 m (1.6 to 3.3 ft).

Exercise 25—Converting multiple FLPs

In this exercise, you will convert multiple FLP files output from FlamMap5 from two MTT random ignition (150 and 300) runs for a sub area of the Mt. Emily landscape.

Click the Risk button on the ArcFuels10 toolbar, then select Batch Convert FLPs from the drop-down list.

Fill out the Batch Convert FLPs form following the figure below.

• Click the Convert button.
• A window will open, indicating the name of the file(s) to be converted is too long. Type a shorter name in the text box and click the OK button.

• A progress meter will open tracking the conversion progress.
• A window will open indicating how many of the files were converted. Click the OK button to close the window.

• Click the Close button to close the Batch Convert FLPs form.

Return to ArcMap.

• The newly created shapefiles and rasters will be within the Layers directory of the Table of Contents in ArcMap
• They are also packaged within the geodatabase you created.

Geodatabase of batch converted FLP data for a sub area within Mt. Emily for both English FLP6 and Metric FLP20 file types.

If you try to convert an already converted file, you will get a series of error windows and warnings.

To continue to the next section go to Convert Fire Size List.

Open topic with navigation