i.evapo.mh

Computes evapotranspiration calculation modified or original Hargreaves formulation, 2001.

Command linePython (grass.script)

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=False, verbose=False, quiet=False, superquiet=False)

Example:

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

Parameters

Command linePython (grass.script)

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: False
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

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.

AUTHOR

Yann Chemin, GRASS Development team, 2007-2016

SOURCE CODE

Available at: i.evapo.mh source code (history)
Latest change: Tuesday Apr 29 14:55:32 2025 in commit 4807e82