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i.biomass(1grass) Grass User's Manual i.biomass(1grass)

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

Last changed: $Date: 2016-05-18 09:07:29 +0200 (Wed, 18 May 2016) $

SOURCE CODE

Available at: i.biomass source code (history)

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© 2003-2016 GRASS Development Team, GRASS GIS 7.2.0 Reference Manual

GRASS 7.2.0