Identification Information
    Citation
        Originator: USDA Forest Service, Geospatial Technology and Applications Center, BAER Imagery Support Program
        Publication Date: 2023-10-06
        Title: Soil Burn Severity Dataset for the hayden Fire occurring on the Salmon-Challis National Forest National Forest
        Publication Information
            Publication Place: Salt Lake City, Utah, USA
            Publisher: USDA Forest Service
        Geospatial Data Presentation Form: raster digital data
        Online Linkage: https://fsapps.nwcg.gov/afm/baer/download.php
    Description
        Abstract: This soil burn severity dataset was derived from Sentinel 2 data and field validated by a Forest Service Burned Area Emergency Response (BAER) team. It is based upon an initial Burned
        Area Reflectance Classification (BARC) dataset created by analyzing satellite imagery. A pre-fire and post-fire Sentinel 2 scene were processed to develop a differenced 
        Normalized Burn Ratio (dNBR) image. The dNBR image attempts to portray the variation of burn severity within a fire and captures the combined effects of the fire to vegetation and soil
        components of the ecosytem. The preliminary BARC dataset was assessed by a Forest Service BAER team and modified, if necessary, based on field conditions. 
        Purpose: These data were created by the USDA Forest Service Geospatial Technology and Applications Center (GTAC) to support Burned Area Emergency Response (BAER) teams.    
    Supplemental Information
        Fire Name: hayden
        Agency: USDA Forest Service
        Type of assessment: Emergency
        Fire size (as mapped): 24169 acres
        Pre-Fire Imagery Date : 2023-07-12
        Post-Fire Imagery Date : 2023-08-13
        Output Dataset Projection: NAD_1983_UTM_Zone_12N
        Datum: D_North_American_1983
        Spheroid Name: GRS_1980
        Mapping Comments: None    
    Product List
        hayden_sbs.tif = Soil burn severity (SBS) dataset in raster format
        hayden_SBS thumb.jpg = JPEG version of the SBS
        
    
    Time Period of Content
        Multiple Dates/Times
            Single Date/Time
                Calendar Date: 2023-07-12 (pre-fire image)
            Single Date/Time
                Calendar Date: 2023-08-13 (post-fire image)
        Currentness Reference: Severity data correspond to the date of the post-fire image.
    Status
        Progress: Evaluation of methods in process
        Maintenance and Update Frequency: As needed
    Spatial Domain
        Bounding Coordinates
            West Bounding Coordinate: 277918.380077
            East Bounding Coordinate: 294698.380077
            North Bounding Coordinate: 4961663.37703
            South Bounding Coordinate: 4948363.37703
    Keywords
        Theme
            Theme Keyword Thesaurus: none
            Theme Keyword: Wildland Fire
            Theme Keyword: Wildfire
            Theme Keyword: Burned Area Emergency Response
            Theme Keyword: BAER
            Theme Keyword: dNBR
            Theme Keyword: Fire Severity
            Theme Keyword: Burn Severity
            Theme Keyword: USDA Forest Service
        Place
            Place Keyword Thesaurus: none
            Place Keyword: ID
            Place Keyword: hayden Fire
    Access Constraints: These data are publicly available. 
    Use Constraints:  There are no restrictions on use, except for reasonable and proper acknowledgement of information sources and limitations as preliminary/draft data.
    Data Set Credit: USDA Forest Service
    Native Data Set Environment: GeoTiff
Data Quality Information
    Positional Accuracy
        Horizontal Positional Accuracy
            Horizontal Positional Accuracy Report: Landsat data are terrain corrected using ground control points and processed to an RMSE of less than 1/2 pixel.
    Lineage
        Process Step
            Process Description: These data products are derived from Sentinel 2 data. Pre-fire and post-fire scenes are analyzed to create a differenced Normalized Burn Ratio (dNBR) image.
                The dNBR image portrays the variation of burn severity within the fire. The pre- and post-fire images are terrain corrected and further processed to convert top of atmosphere reflectance. 
                The Normalized Burn Ratio (NBR) is computed for the pre- and post-fire images using the following formula:
                (NIR Band - SWIR Band) / (NIR Band + SWIR Band) = NBR

                The Differenced NBR is computed to determine severity by subtracting the post-fire NBR from the pre-fire NBR:
                (PreNBR - PostNBR) = dNBR
    		
		Sequence of steps used to create Soil Burn Severity data:

		BARC data verification of burn intensity (defined as vegetative scorch) was conducted by the BAER Team during a field visit on 8/18/2023.  It was determined that the original BARC model had overestimated the amount of moderate burn intensity, particularly in open sagebrush cover types.  		Classification values of the BARC256 dataset were adjusted to better match observations made during field verification.  Despite these adjustments, some minor discrepancies still exist between observed burn intensity and the adjusted BARC model.

		Soil burn severity sampling was conducted during the 8/18/2023 field visit to establish a relationship between burn intensity as shown in the BARC model and the effects of the fire on the soil (burn severity).  The BAER Team determined that high soil burn severity occurred in areas of high burn 		intensity within forested cover types including lodgepole pine, spruce/fir, and Douglas fir.  High burn intensity within other cover types (open cover types such as sparse forest and sagebrush) generally resulted in only moderate soil burn severity, although small, isolated areas of high severity 		occurred where prolonged smoldering occurred on the ground.  Likewise, moderate burn intensity in forested cover types resulted in moderate burn severity, while moderate burn intensity in open cover types resulted in low burn severity.  Therefore, the burn intensity BARC classification thresholds 		were not changed, but the following assumptions were made and applied to the soil burn severity model:

			• All high intensity within lodgepole, spruce/fir, Douglas fir, and whitebark pine cover types is high severity. 
			• All high intensity within any other cover type is moderate severity. 
			• All moderate intensity within lodgepole, spruce/fir, Douglas fir, and whitebark pine cover types is moderate severity. 
			• All moderate intensity within any other cover type is low severity.
			• All low intensity is low severity.
			• The model does not show small, isolated areas of high severity.
			• Some discrepancies still exist because of error associated with the BARC model and cover type mapping.
    
   		Additional Comments:

		In the Hayden2023_BurnSeverity20230819" shapefile, The field "gridcode" is based on the adjusted thresholds shown above (burn intensity).  The field "SEVERITY" is the final soil burn severity after applying the rule set described above to the burn intensity values.

		
            Original BARC thresholds:
                Unburned/Low threshold = 91
                Low/Moderate threshold = 142
                Moderate/High threshold = 219

            Revised SBS thresholds:
                Unburned/Low threshold = 91
                Low/Moderate threshold = 169
                Moderate/High threshold = 222
                
                General descriptions of the severity classes are below:
                Unburned / Very low: The area after the fire was indistinguishable from pre-fire conditions. This does not always indicate the area did not burn
                    (i.e. canopy may be occluding the burn signal).
                Low:      Areas of surface fire with little detected change in cover and little detected mortality of the dominant vegetation. Little to no change in the soil color, structure and condition occured.
                Moderate: This severity class is between low and high and means there is a mixture of detected effects on the dominant vegetation.
                High:     Areas where the canopy has high to complete consumption. Changes to soil structure, color and condition are significant and hydrophobicity may have occured.
Spatial Data Organization Information
    Direct Spatial Reference Method: Raster
    Raster Object Information
        Vertical Count: 1
Spatial Reference Information
    Horizontal Coordinate System Definition
        Planar
            Map Projection
                Map Projection Name: NAD_1983_UTM_Zone_12N
                    Map Projection Parameters
                        Standard Parallel: 0.0
                        Standard Parallel: 0.0
                        Longitude of Central Meridian: -111.0
                        Latitude of Projection Origin: 1.0]];-5120900 -9998100 450445547.391054;-100000 10000;-100000 10000;0.001;0.001;0.001;IsHighPrecisio
                        False Easting: 500000.0
                        False Northing: 0.0
            Planar Coordinate Information
                Planar Coordinate Encoding Method: row and column
                Coordinate Representation
                    Abscissa Resolution: 20.0
                    Ordinate Resolution: 20.0
                Planar Distance Units: Meter
        Geodetic Model
            Horizontal Datum Name: D_North_American_1983
            Ellipsoid Name: GRS_1980
            Semi-major Axis: 6378137.0
            Denominator of Flattening Ratio: 298.257222101
Distribution Information
    Resource Description: Downloadable Data
Metadata Reference Information
    Metadata Date: 2023-10-06
    Metadata Contact
        Contact Information
            Contact Organization Primary
                Contact Organization: USDA Forest Service, Geospatial Technology and Applications Center (GTAC)
                Contact Person: Craig Baker
                Contact Address
                    Address Type: mailing address
                    Address: 125 S. Sate St., Suite 7105
                    City: Salt Lake City
                    State or Province: UT
                    Postal Code: 84138
                Contact Voice Telephone: 801 975 3763 
                Contact Electronic Mail Address: baerimagery@fs.fed.us
