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

# i.eb.evapfr(1grass)

Computes evaporative fraction and root zone soil moisture.

## NAME

**i.eb.evapfr**  - Computes evaporative fraction and root zone soil moisture.

## KEYWORDS

imagery, energy balance, soil moisture, evaporative fraction, SEBAL

## SYNOPSIS

**i.eb.evapfr**\
 **i.eb.evapfr --help**\
 **i.eb.evapfr** \[-**m**\] **netradiation**=*name* **soilheatflux**=*name* **sensibleheatflux**=*name* **evaporativefraction**=*name*  \[**soilmoisture**=*name*\]   \[--**overwrite**\]  \[--**help**\]  \[--**verbose**\]  \[--**quiet**\]  \[--**ui**\]

### Flags:

- **-m**

  Root zone soil moisture output (Makin, Molden and Bastiaanssen, 2001)

- **--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**=*name* **\[required\]**

  Name of Net Radiation raster map \[W/m2\]

- **soilheatflux**=*name* **\[required\]**

  Name of soil heat flux raster map \[W/m2\]

- **sensibleheatflux**=*name* **\[required\]**

  Name of sensible heat flux raster map \[W/m2\]

- **evaporativefraction**=*name* **\[required\]**

  Name for output evaporative fraction raster map

- **soilmoisture**=*name*

  Name for output root zone soil moisture raster map

## DESCRIPTION

*i.eb.evapfr* calculates the evaporative fraction after Bastiaanssen 1995. The main implementation follows Alexandridis et al. (2009). The module takes as input the net radiation (see *r.sun*, *i.eb.netrad*), soil heat flux (see *i.eb.soilheatflux*) and sensible heat flux (see *i.eb.hsebal01*). A flag adds a root zone empirical soil moisture output from the article of Bastiaanssen, et al. (2000).

## REFERENCES

Bastiaanssen, W.G.M., 1995. Estimation of Land surface parameters by remote sensing under clear-sky conditions. PhD thesis, Wageningen University, Wageningen, The Netherlands. (PDF)

Bastiaanssen, W.G.M., Molden, D.J., Makin, I.W., 2000. Remote sensing for irrigated agriculture: examples from research and possible applications. Agricultural water management 46.2: 137-155.

Chemin Y., Alexandridis T.A., 2001. Improving spatial resolution of ET seasonal for irrigated rice in Zhanghe, China. Asian Journal of Geoinformatics. 5(1):3-11.

Alexandridis T.K., Cherif I., Chemin Y., Silleos N.G., Stavrinos E., Zalidis G.C., 2009. Integrated methodology for estimating water use in Mediterranean agricultural areas. Remote Sensing. 1, 445-465. (PDF)

Chemin, Y., 2012. A Distributed Benchmarking Framework for Actual ET Models, in: Irmak, A. (Ed.), Evapotranspiration - Remote Sensing and Modeling. InTech. (PDF)

## SEE ALSO

*i.eb.hsebal01,* *i.eb.netrad,* *i.eb.soilheatflux,* *r.sun*

## AUTHOR

Yann Chemin, Asian Institute of Technology, Thailand

## SOURCE CODE

Available at: i.eb.evapfr source code (history)

Accessed: Monday Feb 24 17:51:31 2025

Main index \| Imagery index \| Topics index \| Keywords index \| Graphical index \| Full index

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