dNBR (burn severity)
The difference between a pre-fire and a post-fire normalized burn ratio, with the published severity ranges it is usually read against.
Experimental: not yet fully verified. How results are checked
dNBR is 0.48, in the moderate-high severity range.
- Severity class
Provenance
- Computed by
- raster.index.dnbr 1.0.0, core 0.1.0
- Model
- dNBR = NBR(pre-fire) - NBR(post-fire); classes from the Key and Benson (2006) ranges
- Accuracy
- Exact arithmetic. The class ranges are a published starting point, not a determination of severity.
- Notes
- 1 shown with the answer
- Cites
- Key, C. H., and Benson, N. C., USDA Forest Service, Rocky Mountain Research Station, Landscape Assessment (LA): sampling and analysis methods, in FIREMON: Fire Effects Monitoring and Inventory System
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: dNBR = NBR(pre-fire) - NBR(post-fire); classes from the Key and Benson (2006) ranges
Accuracy: Exact arithmetic. The class ranges are a published starting point, not a determination of severity.
When to use this: Use this once you have an NBR from before a fire and one from after it: the drop between them is what burn-severity mapping is based on, and it separates ground that burned from ground that was already bare. The class it names is the range the value falls in.
Limitations: The ranges come from western US conifer forests and do not transfer unchanged to other ecosystems; severity mapping normally calibrates them against field plots, and often uses the relativized form (RdNBR) where pre-fire cover varies. Both images need the same sensor, season, and processing, or the difference measures the images rather than the fire.
Worked example: A moderate-high severity burn. Source: Key and Benson 2006: a drop of 0.48 falls in the moderate-high range (0.44 to 0.66). It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.
You enter
- Post-fire NBR
- 0.13
- Pre-fire NBR
- 0.61
You get
- dNBR
- 0.48
- Severity class
- moderate-high severity
Review: Not yet independently reviewed by a GIS professional.
Last verified: 2026-09-22, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 10 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Landscape Assessment (LA): sampling and analysis methods, in FIREMON: Fire Effects Monitoring and Inventory System, Key, C. H., and Benson, N. C., USDA Forest Service, Rocky Mountain Research Station, General Technical Report RMRS-GTR-164-CD, pages LA-1 to LA-55. NBR and dNBR, and the burn-severity ranges offered as a starting point rather than a rule.
Terms
- NBR: normalized burn ratio
- The difference between near-infrared and the longer shortwave-infrared band over their sum. It falls sharply over recently burned ground. Source: Landscape Assessment (LA): sampling and analysis methods, in FIREMON: Fire Effects Monitoring and Inventory System
Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.