## 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: Thursday Oct 30 22:18:32 2025

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