Initial Spread Index

The ISI is an indicator of the head fire intensity, rate of fire spread and difficulty of control in grasslands. It is a combination of the effects of the wind speed and FFMC.

For the interpretation of the map, please refer to the explanation below :-

Class – Difficulty of Control Interpretation
Low Low fire intensity in grass. Fire will spread slowly or be self-extinguishing. Grassland fires can be successfully controlled using hand tools.
Moderate Moderate fire intensity in grass. Hand tools will be effective along the fire’s flanks, but water under pressure (pumps, hose) maybe required to suppress the head fire in grasslands.
High High fire intensity in grass. Direct attack at the fire’s head will require water under pressure, and mechanized equipment may be required to build control lines. (e.g: bulldozer)
Extreme Very high fire intensity in grass. Fire control will require construction of control lines by mechanized equipment and water under pressure. Indirect attack by back-burning between control lines and the fire may be required.

Low = 0 -1     Moderate = 2 - 3     High = 4 - 5     Extreme > 5

Build Up Index

The BUI values shown on the map are indicative values of the amount of fuel available for combustion. It combines DMC and DC which represent medium and heavy dead fuels respectively.

For the interpretation of the map, please refer to the table below :-

Class

Interpretation
Low Medium and heavy fuels are generally not combustible.
Moderate Very low amount of medium and heavy fuels available for combustion.
High Low to moderate amount of medium and heavy fuels available for combustion.
Extreme Moderate to high amount of medium and heavy fuels available for combustion.

Low = 0 - 6     Moderate = 7 - 19     High = 20 - 33     Extreme > 33

Fire Weather Index

The FWI values shown on the map are numerical ratings of fire intensity and general fire danger across the landscape that combine the ISI and BUI. This index is often used to indicate the difficulty of fire control based on the head fire intensity and fire fighting capability.

For the interpretation of the map, please refer to the table below :-

Class Interpretation
Low Fires will be self-extinguishing
Moderate Fire can be easily suppressed with hand tools
High Most fire can be successfully controlled using power pumps and hose

Extreme

Some fires will be difficult to control

Low = 0 - 1     Moderate = 2 - 6     High = 7 - 13     Extreme > 13

Acknowledgement

The output is one of the products of FDRS project under the cooperation programme of the SEA Nations and the Canadian International Development Agency (CIDA). Canadian Forest Service (CFS) is the executing agency appointed by CIDA to implement this project.

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