Enter the Near Infrared (NIR) and Red band values before and after the burn to calculate the Normalized Burn Ratio (NBR).

Normalized Burn Ratio (NBR) Calculation Formula

The following formula is used to calculate the Normalized Burn Ratio (NBR). 

NBR = ((NIRafter - Redafter) - (NIRbefore - Redbefore)) / ((NIRafter + Redafter) + (NIRbefore + Redbefore))

Variables:

  • NIRbefore is the Near Infrared value before the burn.
  • NIRafter is the Near Infrared value after the burn.
  • Redbefore is the Red band value before the burn.
  • Redafter is the Red band value after the burn.

To calculate the NBR, use the formula above by inputting the respective NIR and Red band values before and after the burn event.

What is Normalized Burn Ratio (NBR)?

The Normalized Burn Ratio (NBR) is a satellite-derived index used to identify burned areas and assess the severity of fire damage on vegetation. It leverages the differences in the reflectance properties of healthy vegetation and charred vegetation in the Near Infrared (NIR) and Red bands.

How to Calculate Normalized Burn Ratio (NBR)?

The following steps outline how to calculate the Normalized Burn Ratio (NBR) using the given formula.

  1. First, determine the Near Infrared (NIR) and Red band values before the burn.
  2. Next, determine the Near Infrared (NIR) and Red band values after the burn.
  3. Use the formula from above: NBR = ((NIRafter – Redafter) – (NIRbefore – Redbefore)) / ((NIRafter + Redafter) + (NIRbefore + Redbefore)).
  4. Finally, calculate the NBR by plugging in the values.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

NIRbefore = 0.5

NIRafter = 0.3

Redbefore = 0.2

Redafter = 0.1

FAQ

1. What is the Near Infrared (NIR) band?

The Near Infrared (NIR) band is a region of the electromagnetic spectrum with wavelengths just beyond the visible range. It is often used in remote sensing to assess vegetation health because healthy vegetation strongly reflects NIR light.

2. How is NBR different from other burn indices?

NBR specifically focuses on the changes in NIR and Red band reflectance due to burning. Other indices, like the Normalized Difference Vegetation Index (NDVI), are used to measure vegetation health but are not tailored to identifying burn severity.

3. How often should I use the NBR calculator?

It’s helpful to use the NBR calculator whenever you need to assess the impact of a burn event or monitor vegetation recovery over time.

4. Can this calculator be used for different regions?

Yes, the NBR formula is applicable globally, as it relies on the reflectance properties of vegetation, which are consistent across different regions.

5. Is the calculator accurate?

The calculator provides an estimate of the NBR based on the inputs provided. For precise analysis, it is best to use satellite imagery data and appropriate software tools.