Fire Weather/Danger Terminology

 

ERC=Energy Release Component.  ERC in an indices of the National Fire Danger Rating System (NFDRS).   It is build up index; a measurement of potential energy in the fuel bed.  The longer it days hot and dry the greater the buildup of energy.  It is used to measure resistance to control. 

1000 hr=1,000 hour dead fuels.  This is a dead fuel 3 to 8 inches in diameter.  We use 1,000 hr fuels moistures to measure extended dry conditions. The lower the fuel moisture the drier it is.  Once we drop below 10% we know we are very dry. Traditional suppression methods may be ineffective. 

GSI=Growing Season Index.  We use >0.5 as indicators that live fine fuels are in a green up phase.  <0.5 indicates fine fuels will support active burning.  

KBDI = Keetch-Byron Drought Index.  It is a scale from 0 to 800.  The higher the number the drier we are.  A KBDI of 500 would mean we would need 5 inches of precip to fully saturate the soils.  

DSCI = The Drought Severity and Coverage Index is an experimental method for converting drought levels from the U.S. Drought Monitor map to a single value for an area.  

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