i.biomass(1)

NAME
i.biomass - Computes biomass growth, precursor of crop yield calculation.

KEYWORDS
imagery, biomass, FPAR, yield

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

  Flags:

--overwrite
    Allow output files to overwrite existing files

--help
    Print usage summary

--verbose
    Verbose module output

--quiet
    Quiet module output

--ui
    Force launching GUI dialog

  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]

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.

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

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.

AUTHOR
Yann Chemin, Bec de Mortagne, France

SOURCE CODE

Available at: i.biomass source code (history)

Accessed: Tuesday Jun 16 04:05:34 2026

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