i.evapo.mh(1)

NAME
i.evapo.mh - Computes evapotranspiration calculation modified or original Hargreaves formulation, 2001.

KEYWORDS
imagery, evapotranspiration

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

  Flags:

-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

--ui
    Force launching GUI dialog

  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]

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: Friday Apr 17 01:04:26 2026 in commit: 5a31d549cc0150239894bd2b9e67250af87d38b5

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