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i.eb.eta

Actual evapotranspiration for diurnal period (Bastiaanssen, 1995).

i.eb.eta netradiationdiurnal=name evaporativefraction=name temperature=name output=name [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

i.eb.eta netradiationdiurnal=rnetday evaporativefraction=evapfr temperature=tempk output=name

grass.script.run_command("i.eb.eta", netradiationdiurnal="rnetday", evaporativefraction="evapfr", temperature="tempk", output, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

gs.run_command("i.eb.eta", netradiationdiurnal="rnetday", evaporativefraction="evapfr", temperature="tempk", output="name")

grass.tools.Tools.i_eb_eta(netradiationdiurnal="rnetday", evaporativefraction="evapfr", temperature="tempk", output, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

tools = Tools()
tools.i_eb_eta(netradiationdiurnal="rnetday", evaporativefraction="evapfr", temperature="tempk", output="name")

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

Parameters

netradiationdiurnal=name [required]
    Name of the diurnal net radiation map [W/m2]
    Default: rnetday
evaporativefraction=name [required]
    Name of the evaporative fraction map [-]
    Default: evapfr
temperature=name [required]
    Name of the surface skin temperature [K]
    Default: tempk
output=name [required]
    Name of the output actual evapotranspiration layer [mm/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

netradiationdiurnal : str, required
    Name of the diurnal net radiation map [W/m2]
    Used as: input, raster, name
    Default: rnetday
evaporativefraction : str, required
    Name of the evaporative fraction map [-]
    Used as: input, raster, name
    Default: evapfr
temperature : str, required
    Name of the surface skin temperature [K]
    Used as: input, raster, name
    Default: tempk
output : str, required
    Name of the output actual evapotranspiration layer [mm/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

netradiationdiurnal : str | np.ndarray, required
    Name of the diurnal net radiation map [W/m2]
    Used as: input, raster, name
    Default: rnetday
evaporativefraction : str | np.ndarray, required
    Name of the evaporative fraction map [-]
    Used as: input, raster, name
    Default: evapfr
temperature : str | np.ndarray, required
    Name of the surface skin temperature [K]
    Used as: input, raster, name
    Default: tempk
output : str | type(np.ndarray) | type(np.array) | type(gs.array.array), required
    Name of the output actual evapotranspiration layer [mm/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.eb.eta calculates the actual evapotranspiration (ETa ; mm/d) for diurnal period after [1], implemented in [3]. It takes input of Diurnal Net Radiation (see r.sun), evaporative fraction (see i.eb.evapfr) and surface skin temperature.

NOTES

Full ETa processing will need those:

  • i.vi, i.albedo, r.latlong, i.emissivity
  • i.evapo.potrad (GRASS Addon)
  • i.eb.netrad, i.eb.soilheatflux, i.eb.hsebal01
  • i.eb.evapfr, i.eb.eta

(for time integration: i.evapo.time_integration)

For more details on the algorithms see [1][2][3][4].

REFERENCES

[1] Bastiaanssen, W.G.M., 1995. Estimation of Land surface parameters by remote sensing under clear-sky conditions. PhD thesis, Wageningen University, Wageningen, The Netherlands. (PDF)

[2] Chemin Y., Alexandridis T.A., 2001. Improving spatial resolution of ET seasonal for irrigated rice in Zhanghe, China. Asian Journal of Geoinformatics. 5(1):3-11,2004.

[3] Alexandridis T.K., Cherif I., Chemin Y., Silleos N.G., Stavrinos E., Zalidis G.C. Integrated methodology for estimating water use in Mediterranean agricultural areas. Remote Sensing. 2009, 1, 445-465. (PDF)

[4] Chemin, Y., 2012. A Distributed Benchmarking Framework for Actual ET Models, in: Irmak, A. (Ed.), Evapotranspiration - Remote Sensing and Modeling. InTech. (PDF)

SEE ALSO

r.sun, i.eb.evapfr, i.eb.netrad

AUTHOR

Yann Chemin, Asian Institute of Technology, Thailand

SOURCE CODE

Available at: i.eb.eta source code (history)
Latest change: Thursday Jun 26 21:25:27 2025 in commit 3ec2b13