Skip to content

i.evapo.mh

Computes evapotranspiration calculation modified or original Hargreaves formulation, 2001.

i.evapo.mh [-zhs] netradiation_diurnal=name average_temperature=name minimum_temperature=name maximum_temperature=name [precipitation=name] output=name [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

i.evapo.mh netradiation_diurnal=name average_temperature=name minimum_temperature=name maximum_temperature=name output=name

grass.script.run_command("i.evapo.mh", netradiation_diurnal, average_temperature, minimum_temperature, maximum_temperature, precipitation=None, output, flags=None, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

gs.run_command("i.evapo.mh", netradiation_diurnal="name", average_temperature="name", minimum_temperature="name", maximum_temperature="name", output="name")

grass.tools.Tools.i_evapo_mh(netradiation_diurnal, average_temperature, minimum_temperature, maximum_temperature, precipitation=None, output, flags=None, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

tools = Tools()
tools.i_evapo_mh(netradiation_diurnal="name", average_temperature="name", minimum_temperature="name", maximum_temperature="name", output="name")

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

Parameters

netradiation_diurnal=name [required]
    Name of input diurnal net radiation raster map [W/m2/d]
average_temperature=name [required]
    Name of input average air temperature raster map [C]
minimum_temperature=name [required]
    Name of input minimum air temperature raster map [C]
maximum_temperature=name [required]
    Name of input maximum air temperature raster map [C]
precipitation=name
    Name of precipitation raster map [mm/month]
    Disabled for original Hargreaves (1985)
output=name [required]
    Name for output raster map [mm/d]
-z
    Set negative ETa to zero
-h
    Use original Hargreaves (1985)
-s
    Use Hargreaves-Samani (1985)
--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

netradiation_diurnal : str, required
    Name of input diurnal net radiation raster map [W/m2/d]
    Used as: input, raster, name
average_temperature : str, required
    Name of input average air temperature raster map [C]
    Used as: input, raster, name
minimum_temperature : str, required
    Name of input minimum air temperature raster map [C]
    Used as: input, raster, name
maximum_temperature : str, required
    Name of input maximum air temperature raster map [C]
    Used as: input, raster, name
precipitation : str, optional
    Name of precipitation raster map [mm/month]
    Disabled for original Hargreaves (1985)
    Used as: input, raster, name
output : str, required
    Name for output raster map [mm/d]
    Used as: output, raster, name
flags : str, optional
    Allowed values: z, h, s
    z
        Set negative ETa to zero
    h
        Use original Hargreaves (1985)
    s
        Use Hargreaves-Samani (1985)
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

netradiation_diurnal : str | np.ndarray, required
    Name of input diurnal net radiation raster map [W/m2/d]
    Used as: input, raster, name
average_temperature : str | np.ndarray, required
    Name of input average air temperature raster map [C]
    Used as: input, raster, name
minimum_temperature : str | np.ndarray, required
    Name of input minimum air temperature raster map [C]
    Used as: input, raster, name
maximum_temperature : str | np.ndarray, required
    Name of input maximum air temperature raster map [C]
    Used as: input, raster, name
precipitation : str | np.ndarray, optional
    Name of precipitation raster map [mm/month]
    Disabled for original Hargreaves (1985)
    Used as: input, raster, name
output : str | type(np.ndarray) | type(np.array) | type(gs.array.array), required
    Name for output raster map [mm/d]
    Used as: output, raster, name
flags : str, optional
    Allowed values: z, h, s
    z
        Set negative ETa to zero
    h
        Use original Hargreaves (1985)
    s
        Use Hargreaves-Samani (1985)
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.evapo.mh calculates the reference evapotranspiration (ET) after Hargreaves et al. (1985), Hargreaves and Samani (1985) and the Modified Hargreaves version found in Droogers and Allen (2002).

REFERENCES

  • Hargreaves GL, Hargreaves GH, Riley JP, 1985. Agricultural benefits for Senegal River Basin. Journal of Irrigation and Drainange Engineering, ASCE, 111(2):113-124.
  • Droogers P, Allen RG, 2002. Towards a simplified global reference evapotranspiration equation. Irrigation Science.
  • Droogers, P., Allen RG. 2002. Estimating reference evapotranspiration under inaccurate data conditions. Irrigation and Drainage Systems 16: 33-45.
  • Hargreaves GH, Samani ZA, 1985. Reference crop evapotranspiration from ambient air temperature. American Society of Agricultural Engineers (Microfiche collection)(USA). no. fiche no. 85-2517.

SEE ALSO

i.evapo.pt, i.evapo.pm, i.evapo.time, r.sun

AUTHOR

Yann Chemin, GRASS Development team, 2007-2016

SOURCE CODE

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