improver.fire_weather.fire_weather_index module

improver.fire_weather.fire_weather_index module#

Plugin to calculate the fire weather index (FWI).

class FireWeatherIndex[source]#

Bases: FireWeatherBase

Plugin to calculate the fire weather index (FWI).

The FWI combines the Initial Spread Index (ISI) and the Build Up Index (BUI) to provide a numerical rating of fire intensity. It represents the rate of fire spread and the amount of available fuel.

This process is adapted directly from:

Equations and FORTRAN Program for the Canadian Forest Fire Weather Index System (C.E. Van Wagner and T.L. Pickett, 1985). Pages 7-8, Equations 28-30.

Expected input units:

  • Initial Spread Index (ISI): dimensionless

  • Build Up Index (BUI): dimensionless

INPUT_CUBE_NAMES: list[str] = ['initial_spread_index', 'build_up_index']#
METADATA_SOURCE_CUBE: str = 'build_up_index'#
OUTPUT_CUBE_NAME: str = 'fire_weather_index'#
VALID_OUTPUT_RANGE: tuple[float | None, float | None] | None = (0.0, 100)#
_abc_impl = <_abc._abc_data object>#
_calculate()[source]#

Calculate the Fire Weather Index (FWI).

From Van Wagner and Pickett (1985), Page 8: Steps 4-6

Return type:

ndarray

Returns:

The calculated FWI values.

_calculate_extrapolated_duff_moisture_function()[source]#

Calculates the extrapolated Duff Moisture Function (extrapolated_DMF) from the Build Up Index (BUI).

From Van Wagner and Pickett (1985), Page 7-8: Equations 28a and 28b.

Return type:

ndarray

Returns:

The calculated extrapolated_DMF values.

_calculate_fwi(extrapolated_DMF)[source]#

Calculates the Fire Weather Index (FWI) from the Initial Spread Index (ISI) and the extrapolated Duff Moisture Function (extrapolated_DMF).

From Van Wagner and Pickett (1985), Page 7-8: Equations 29-30.

Return type:

ndarray

Returns:

The calculated FWI values.

build_up_index: Cube#
initial_spread_index: Cube#