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i.biomass

Computes biomass growth, precursor of crop yield calculation.

i.biomass fpar=name lightuse_efficiency=name latitude=name dayofyear=name transmissivity_singleway=name water_availability=name output=name [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

i.biomass fpar=name lightuse_efficiency=name latitude=name dayofyear=name transmissivity_singleway=name water_availability=name output=name

grass.script.run_command("i.biomass", fpar, lightuse_efficiency, latitude, dayofyear, transmissivity_singleway, water_availability, output, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

gs.run_command("i.biomass", fpar="name", lightuse_efficiency="name", latitude="name", dayofyear="name", transmissivity_singleway="name", water_availability="name", output="name")

grass.tools.Tools.i_biomass(fpar, lightuse_efficiency, latitude, dayofyear, transmissivity_singleway, water_availability, output, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

tools = Tools()
tools.i_biomass(fpar="name", lightuse_efficiency="name", latitude="name", dayofyear="name", transmissivity_singleway="name", water_availability="name", output="name")

This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.

Parameters

fpar=name [required]
    Name of fPAR raster map
lightuse_efficiency=name [required]
    Name of light use efficiency raster map (UZB:cotton=1.9)
latitude=name [required]
    Name of degree latitude raster map [dd.ddd]
dayofyear=name [required]
    Name of Day of Year raster map [1-366]
transmissivity_singleway=name [required]
    Name of single-way transmissivity raster map [0.0-1.0]
water_availability=name [required]
    Value of water availability raster map [0.0-1.0]
output=name [required]
    Name for output daily biomass growth raster map [kg/ha/d]
--overwrite
    Allow output files to overwrite existing files
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

fpar : str, required
    Name of fPAR raster map
    Used as: input, raster, name
lightuse_efficiency : str, required
    Name of light use efficiency raster map (UZB:cotton=1.9)
    Used as: input, raster, name
latitude : str, required
    Name of degree latitude raster map [dd.ddd]
    Used as: input, raster, name
dayofyear : str, required
    Name of Day of Year raster map [1-366]
    Used as: input, raster, name
transmissivity_singleway : str, required
    Name of single-way transmissivity raster map [0.0-1.0]
    Used as: input, raster, name
water_availability : str, required
    Value of water availability raster map [0.0-1.0]
    Used as: input, raster, name
output : str, required
    Name for output daily biomass growth raster map [kg/ha/d]
    Used as: output, raster, name
overwrite : bool, optional
    Allow output files to overwrite existing files
    Default: None
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

fpar : str | np.ndarray, required
    Name of fPAR raster map
    Used as: input, raster, name
lightuse_efficiency : str | np.ndarray, required
    Name of light use efficiency raster map (UZB:cotton=1.9)
    Used as: input, raster, name
latitude : str | np.ndarray, required
    Name of degree latitude raster map [dd.ddd]
    Used as: input, raster, name
dayofyear : str | np.ndarray, required
    Name of Day of Year raster map [1-366]
    Used as: input, raster, name
transmissivity_singleway : str | np.ndarray, required
    Name of single-way transmissivity raster map [0.0-1.0]
    Used as: input, raster, name
water_availability : str | np.ndarray, required
    Value of water availability raster map [0.0-1.0]
    Used as: input, raster, name
output : str | type(np.ndarray) | type(np.array) | type(gs.array.array), required
    Name for output daily biomass growth raster map [kg/ha/d]
    Used as: output, raster, name
overwrite : bool, optional
    Allow output files to overwrite existing files
    Default: None
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

Returns:

result : grass.tools.support.ToolResult | np.ndarray | tuple[np.ndarray] | None
If the tool produces text as standard output, a ToolResult object will be returned. Otherwise, None will be returned. If an array type (e.g., np.ndarray) is used for one of the raster outputs, the result will be an array and will have the shape corresponding to the computational region. If an array type is used for more than one raster output, the result will be a tuple of arrays.

DESCRIPTION

i.biomass calculates the biomass growth for a day after [1][2]. Input:

  • fPAR, the modified Photosynthetic Active Radiation for crops.
  • Light Use Efficiency [0.0-1.0], in Uzbekistan cotton is at 1.9 most of the time.
  • Latitude [0.0-90.0], from r.latlong.
  • DOY [1-366].
  • Transmissivity of the atmosphere single-way [0.0-1.0], mostly around 0.7+ in clear sky.
  • Water availability [0.0-1.0], possibly using direct output from i.eb.evapfr.

NOTES

i.biomass can use the output of i.eb.evapfr directly as water availability input.

TODO

Remove Latitude, DOY and Tsw from input and replace with a raster input compatible with r.sun output.

REFERENCES

[1] Bastiaanssen, W.G.M., Ali, S., 2002. A new crop yield forecasting model based on satellite measurements applied across the Indus Basin, Pakistan. Agriculture, Ecosystems and Environment, 94(3):321-340. (PDF)

[2] Chemin, Y., Platonov, A., Abdullaev, I., Ul-Hassan, M. 2005. Supplementing farm level water productivity assessment by remote sensing in transition economies. Water International. 30(4):513-521.

SEE ALSO

i.eb.evapfr, r.latlong, r.sun

AUTHOR

Yann Chemin, Bec de Mortagne, France

SOURCE CODE

Available at: i.biomass source code (history)
Latest change: Friday Aug 08 09:39:19 2025 in commit ed72c71