---
name: "i.evapo.mh"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "8.4.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/i.evapo.mh"
---

# i.evapo.mh(1grass)

Computes evapotranspiration calculation modified or original Hargreaves formulation, 2001.

## 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: Monday Feb 24 17:51:32 2025

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