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)

       Accessed: Friday Apr 04 01:20:51 2025

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       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                                   i.evapo.mh(1grass)