Spatial datasets of probabilistic wildfire risk components for the United States (270m)

Metadata:

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Pixel

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: USA Contiguous Albers Equal Area Conic USGS version

Albers_Conical_Equal_Area:

Standard_Parallel: 29.5

Standard_Parallel: 45.5

Longitude_of_Central_Meridian: -96.0

Latitude_of_Projection_Origin: 23.0

False_Easting: 0.0

False_Northing: 0.0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.0000000037527980722984474

Ordinate_Resolution: 0.0000000037527980722984474

Planar_Distance_Units: meter

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: GRS 1980

Semi-major_Axis: 6378137.0000

Denominator_of_Flattening_Ratio: 298.257222101

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:

Below is a description of the files included in this data publication.

DATA FILES - BURN PROBABILITY (3)
All burn probablity data files are Georeferenced TIFF (GeoTIFF) files and include additional associated files (e.g., *.xml, *.tfw, and *.ovr).

1. \Data\I_FSim_CONUS_LF2020_270m\CONUS_BP.tif: Modeled national burn probability (BP) data for the conterminous United States at a 270-meter grid spatial resolution.

2. \Data\II_FSim_Alaska_LF2020_270m\AK_BP.tif: Modeled national BP data for Alaska at a 270-meter grid spatial resolution.

3. \Data\III_FSim_Hawaii_LF2020_270m\HI_BP.tif: Modeled national BP data for Hawaii at a 270-meter grid spatial resolution.

Values in the BP data layer indicate, for each pixel, the number of times that cell was burned by an FSim-modeled fire, divided by the total number of annual iterations simulated. The burn probability layer depicts only one component of wildfire risk, indicating the tendency of any given pixel to burn, given the static circa 2020 landscape conditions depicted by the LANDFIRE data, contemporary weather and ignition patterns, as well as contemporary fire management policies (entailing considerable fire prevention and suppression efforts). Pixels with burnable fuel types that did not burn in any simulation iterations (20,000-100,000 iterations depending on pyrome) were assigned a nominal burn probability value of 0.000008 (1 in 120,000). This value is lower than any value calculated through the simulations and prevents subsequent calculations of hazard or risk on these pixels from automatically being zero.

The BP data do not, and are not intended to, depict fire-return intervals of any vintage, nor do they indicate projected fire footprints or routes of travel. Nothing about the expected shape or size of any actual fire incident can be interpreted from the burn probabilities. Instead, the BP data, in conjunction with the FLP layers, are intended to support an actuarial approach to quantitative wildfire risk analysis (e.g., see Thompson et al. 2011).



DATA FILES - CONDITIONAL FLAME-LENGTH PROBABILITY (18)
All conditional flame-length probablity data files are Georeferenced TIFF (GeoTIFF) files and include additional associated files (e.g., *.xml, *.tfw, and *.ovr).

1-6. \Data\I_FSim_CONUS_LF2020_270m\CONUS_FLP#.tif: Conditional flame-length probability (FLP) data for the conterminous United States at a 270-meter grid spatial resolution (# = 1-6, which represents the different flame length probability levels described below).

7-12. \Data\II_FSim_Alaska_LF2020_270m\AK_FLP#.tif: Conditional FLP data for Alaska at a 270-meter grid spatial resolution (# = 1-6, which represents the different flame length probability levels described below).

13-18. \Data\III_FSim_Hawaii_LF2020_270m\HI_FLP#.tif: Conditional FLP data for Hawaii at a 270-meter grid spatial resolution (# = 1-6, which represents the different flame length probability levels described below).

Values in the FLP layers indicate, of all simulated fires that burned a given cell, the proportion in each Flame Length Probability (flame-length class). The six FLPs correspond to flame-length classes as follows:
FLP1 = < 2 feet (ft.)
FLP2 = 2 < 4 ft.
FLP3 = 4 < 6 ft.
FLP4 = 6 < 8 ft.
FLP5 = 8 < 12 ft.
FLP6 = 12+ ft.

Burnable fuel types that did not burn within simulation limits (20,000-100,000 annual weather scenarios modeled, depending on the pyrome) were assigned an average FLP value based on the pyrome-wide mean of similar pixels. The purpose of assigning FLP values in these cases is so subsequent calculations of wildfire hazard and risk will not automatically equal zero at these pixels. FLP rasters were divided into zones based on combination of pyrome, surface fuel model, and presence or absence of burnable canopy cover (defined as Canopy Cover > 0 and Canopy Base Height <= 30). Zonal means were calculated in ArcGIS for every combination, and pixels with burnable fuel models that did not burn during simulations were assigned the mean value from burned pixels with the same combination of pyrome, fuel model, and burnable canopy presence/absence. Values assigned in this manner were checked and adjusted where necessary to ensure that the six FLP rasters summed to one in all cases. The reliability of FLP estimations likely increases with the number of simulations where a pixel was burned.

The utility of the calibrated FSim BP and FLP data for quantitative geospatial wildfire risk assessment is described in Thompson et al. (2011) and Scott et al. (2013).



SUPPLEMENTAL FILES (6)
All supplemental files are Portable Network Graphics (PNG) files.

1. \Supplements\CONUS_LF2020_BP_270m.png: Burn probability (BP) map for the conterminous United States using class breaks on a full log (1/3-log) scale.

2. \Supplements\CONUS_ LF2020_ FLP#_270m.png: Conditional flame length probability (FLP) maps for each of the six flame length classes for the conterminous United States using class breaks of 0.1.

3. \Supplements\AK_LF2020_BP_270m.png: BP map for Alaska using class breaks on a full log (1/3-log) scale.

4. \Supplements\AK_ LF2020_ FLP#_270m.png: Conditional FLP maps for each of the six flame length classes for Alaska using class breaks of 0.1.

5. \Supplements\HI_LF2020_BP_270m.png: BP map for Hawaii using class breaks on a full log (1/3-log) scale.

6. \Supplements\HI_ LF2020_ FLP#_270m.png: Conditional FLP maps for each of the six flame length classes for Hawaii using class breaks of 0.1.

Entity_and_Attribute_Detail_Citation:

Thompson, Matthew P.; Calkin, David E.; Finney, Mark A.; Ager, Alan A.; Gilbertson-Day, Julie W. 2011. Integrated national-scale assessment of wildfire risk to human and ecological values. Stochastic Environmental Research and Risk Assessment 25:761-780. https://doi.org/10.1007/s00477-011-0461-0

Scott, Joe H.; Thompson, Matthew P.; Calkin, David E. 2013. A wildfire risk assessment framework for land and resource management. Gen. Tech. Rep. RMRS-GTR-315. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 83 p. https://doi.org/10.2737/rmrs-gtr-315

Metadata_Reference_Information:

Metadata_Date: 20230920

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: USDA Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory

Contact_Person: Greg Dillon

Contact_Position: Director, Fire Modeling Institute

Contact_Address:

Address_Type: mailing and physical

Address: Missoula Fire Sciences Laboratory

Address: 5775 US Hwy 10 W

City: Missoula

State_or_Province: MT

Postal_Code: 59808

Country: USA

Contact_Voice_Telephone: 406-329-4800

Contact_Electronic_Mail_Address: greg.dillon@usda.gov

Contact Instructions: This contact information was current as original publication date. For current information see Contact Us page on: https://doi.org/10.2737/RDS.

Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998