The response depends on the intensity and behavior of a fire. Fires do not burn with uniform intensity across landscapesrather they leave a mosaic of altered habitats. Though some burned areas will respond naturally with vigorous re-growth, others demand more immediate and intensive efforts. Satellite maps help recovery teams to pinpoint the places where their efforts are most needed, and to determine the type of response that would be most appropriate.
Near the end of a fire's life, a Burned Area Emergency Response (BAER) team, including geographic information systems (GIS) specialists, wildlife biologists and hydrologists, assesses the condition of the land. Within a week of this assessment the team creates a prescription plan used by local fire response teams to protect the public and residences. A critical part of this assessment includes mapping soil burn severity, which the BAER team does using Landsat-derived maps provided by the RSAC.
To create the initial burn map used by the BAER team, the RSAC first generates Normalized Burned Ratio (NBR) maps from Landsat's near infrared and shortwave infrared data acquired before and after the fire. Next the RSAC creates a differenced NBR (dNBR) image by subtracting the post-fire NBR data from the pre-fire NBR data. The resulting map delineates the burned area and corresponding ecosystem changes. BAER teams use the RSAC's burn map to generate a soil burn severity map that is used to assess and identify potential hazards and risk, which often follow fires.
|Contact: Rob Gutro|
NASA/Goddard Space Flight Center