Fire Danger Index
Chandler Burning Index (CBI)
The Chandler Burning Index (CBI) uses the air temperature and relative humidity to calculate a numerical index of fire danger. That number is then equated to the Fire Danger severity of either extreme, very high, high, moderate, or low. It's based solely on weather conditions, with no adjustment for fuel moisture.
CBI < 50
|
Low |
50 < CBI < 75
|
Moderate |
75 < CBI < 90
|
High |
90 < CBI < 97,5
|
Very high |
CBI > 98
|
Extreme |
|
0
s-o-t
|
Current risk
Fuels do not ignite readily from small firebrands although a more intense heat source, such as lightning, may start fires in duff or punky wood. Fires in open cured grasslands may burn freely a few hours after rain, but woods fires spread slowly by creeping or smoldering, and burn in irregular fingers. There is little danger of spotting.
|
Formula --> CBI = (((110 - 1.373 * RH) - 0.54 * (10.20 - T)) * (124 * 10
(-0.0142 * RH)))/60
T = Air temperature |
[°C]
|
/ |
RH = Relative humidity |
[ %]
|
Application --> CBI = (((110 - 1.373 *
80.0 ) - 0.54 * (10.20 -
5.1)) * (124 * 10
(-0.0142 * 80.0 )))/60 ≅
0