Enter the near-infrared value and the shortwave-infrared value into the calculator to determine the normalized burn ratio (NBR).

NBR Formula

The following formula is used to calculate a normalized burn ratio: 

NBR = (NIR-SWIR) / (NIR + SWIR)
  • Where NBR is the normalized burn ratio
  • NIR is the near-infrared light value
  • SWIR is the shortwave infrared value

What is NBR (normalized burn ratio)?

NBR, or Normalized Burn Ratio, is a valuable tool used by scientists and researchers to assess the severity and extent of wildfires. It is a numerical index derived from satellite imagery that measures the difference in reflectance between pre- and post-fire conditions.

By comparing the reflectance values of different wavelengths before and after a fire, NBR provides a quantitative measure of the burn severity. It considers the changes in vegetation cover and the charred area caused by the fire, allowing scientists to assess the impact and intensity of the burn.

NBR is crucial because it provides valuable information about the ecological effects of wildfires. It helps scientists understand the severity of a fire and its potential impact on ecosystems, vegetation recovery, and soil erosion.

By analyzing NBR data, researchers can determine the extent of vegetative loss and assess the health and resilience of the affected ecosystem.

Additionally, NBR plays a vital role in post-fire management and planning. It helps identify areas that require immediate attention for restoration and rehabilitation efforts. By quantifying the burn severity, land managers can prioritize resources and allocate them effectively to needy areas.

NBR is essential for fire risk assessment and monitoring. By analyzing historical NBR data and patterns, researchers can develop models to predict future fire risks and anticipate areas prone to severe burns.

Example Problem

How to calculate NBR?

First, determine the value of the near-infrared light. For this example, the NIR is found to be .85.

Next, determine the shortwave infrared light value. For this example, the SWIR value is found to be .65.

Finally, calculate the NBR using the formula above:

NBR = (NIR-SWIR) / (NIR + SWIR)

NBR = (.85-.65) / (.85+.65)

NBR = .1333