Identification Information Citation Originator: USDA Forest Service, Geospatial Technology and Applications Center, BAER Imagery Support Program Publication Date: 2018-01-03 Title: Soil Burn Severity data for the THOmAS Fire occurring on the Los Padres National Forest - 2017 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?year=2017 Description Abstract:This is the final Soil Burn Severity (SBS) dataset for the Thomas fire, occuring on the Los Padres National Forest in California. The final SBS is based on a preliminary Burned Area Reflectance Classification (BARC) product which has been field-validated and modified by a U.S. Forest Service Burned Area Emergency Response (BAER) team. The BARC dataset is produced by first creating a Normalized Burn Ratio for both a pre and post-fire Sentinel 2 image and then differencing the two into a dNBR. The dNBR image attempts to portray the variation of burn severity within a fire. The severity rating is based upon a composite of the severity to the understory (grass, shrub layers), midstory trees and overstory trees. Because there is often a strong correlation between canopy consumption and soil effects, this algorithm works in many cases for BAER teams whose objective is a soil burn severity assessment. It is not, however, appropriate in all ecosystems or fires. Purpose: These data were created by the USDA Forest Service Geospatial Technology and Applications Center (GTAC) to support Burned Area Emergency Response (BAER) teams with post-fire condition assessment. Supplemental Information Fire Name: THOMAS Agency: USDA Forest Service Land Management Unit: Los Padres National Forest Type of assessment: Emergency Fire size (as mapped): 272,845 acres Pre-Fire Imagery Date: 2017-11-28 Post-Fire Imagery Date: 2017-12-28 Output Dataset Projection: UTM Zone 11N Datum: WGS84 Spheroid Name: WGS84 Product List thomas_soil_burn_severity.tif 1 = unburned / undetectable (Dark Green) 2 = low severity (Cyan) 3 = moderate severity (Yellow) 4 = high severity (Red) Time Period of Content Multiple Dates/Times Single Date/Time Calendar Date: 2017-11-28 (pre-fire image) Single Date/Time Calendar Date: 2017-12-28 (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: -119.686485 East Bounding Coordinate: -118.921365 North Bounding Coordinate: 34.646413 South Bounding Coordinate: 34.271207 Keywords Theme Theme Keyword Thesaurus: none Theme Keyword: Wildland Fire Theme Keyword: Wildfire Theme Keyword: Burned Area Emergency Response Theme Keyword: BAER Theme Keyword: differenced Normalized Burn Ratio Theme Keyword: dNBR Theme Keyword: Fire Severity Theme Keyword: Burn Severity Theme Keyword: USDA Forest Service Theme Keyword: Sentinel 2 Place Place Keyword Thesaurus: none Place Keyword: Los Padres National Forest Place Keyword: THOMAS Fire Access Constraints: Thresholded, preliminary severity estimates (BARC4 and BARC256) are only delivered to BAER teams. Further distribution is at the discretion of the BAER team leader. Pre-imagery, post-imagery, and unthresholded data are publicly available on http://activefiremaps.fs.fed.us/baer/download.php. Access to pre-imagery and post-imagery may be limited when sensors other than Landsat or other government remote sensing assets are used due to product licensing restrictions. 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: ERDAS Imagine, ESRI ArcGIS Data Quality Information Positional Accuracy Horizontal Positional Accuracy Horizontal Positional Accuracy Report: Data are terrain corrected to less than 1 pixel, relative mean-squared error. Lineage Process Step Process Description: These data products are derived from Sentinel 2B MSI data. Pre-fire and post-fire scenes were 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 The BARC products are a generalization of the raw, continuous dNBR dataset. Both BARC products have been resampled to unsigned 8-bit GeoTIFF and are easily viewed and edited within ArcGIS. General descriptions of the severity classes are below: Unburned / Undetectable: This means 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: This severity class represents areas of surface fire with little detected change in cover and little detected mortality of the dominant vegetation. Moderate: This severity class is between low and high and means there is a mixture of detected effects on the dominant vegetation. High: This severity class represents areas where the canopy has high to complete consumption. Spatial Data Organization Information Direct Spatial Reference Method: Raster Raster Object Information Vertical Count: 1 Spatial Reference Information Horizontal Coordinate System Definition Planar Grid Coordinate System Grid Coordinate System Name: WGS84_UTM_Zone_11N Universal Transverse Mercator UTM Zone Number: 11N Transverse Mercator Scale Factor at Central Meridian: 0.9996 Longitude of Central Meridian: -117.0 Latitude of Projection Origin: 0.0 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: WGS84 Ellipsoid Name: WGS84 Distribution Information Resource Description: Downloadable Data Metadata Reference Information Metadata Date: 2018-01-03 Metadata Contact Contact Information Contact Organization Primary Contact Organization: USDA Forest Service, Geospatial Technology and Applications Center (GTAC) Contact Person: Justin Epting Contact Address Address Type: mailing address Address: 2222 W. 2300 S. City: Salt Lake City State or Province: UT Postal Code: 84119 Contact Voice Telephone: 801 975 3755 Contact Electronic Mail Address: baerimagery@fs.fed.us