---
name: "i.eb.hsebal01"
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.hsebal01"
---

# i.eb.hsebal01(1grass)

Computes sensible heat flux iteration SEBAL 01.

## NAME

**i.eb.hsebal01**  - Computes sensible heat flux iteration SEBAL 01.

## KEYWORDS

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

## SYNOPSIS

**i.eb.hsebal01**\
 **i.eb.hsebal01 --help**\
 **i.eb.hsebal01** \[-**ac**\] **netradiation**=*name* **soilheatflux**=*name* **aerodynresistance**=*name* **temperaturemeansealevel**=*name* **vapourpressureactual**=*name* **frictionvelocitystar**=*float*  \[**row\_wet\_pixel**=*float*\]   \[**column\_wet\_pixel**=*float*\]   \[**row\_dry\_pixel**=*float*\]   \[**column\_dry\_pixel**=*float*\]  **output**=*name*  \[--**overwrite**\]  \[--**help**\]  \[--**verbose**\]  \[--**quiet**\]  \[--**ui**\]

### Flags:

- **-a**

  Automatic wet/dry pixel (careful!)

- **-c**

  Dry/Wet pixels coordinates are in image projection, not row/col

- **--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 instantaneous net radiation raster map \[W/m2\]

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

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

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

  Name of aerodynamic resistance to heat momentum raster map \[s/m\]

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

  Name of altitude corrected surface temperature raster map \[K\]

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

  Name of the actual vapour pressure (e\_act) map \[KPa\]

- **frictionvelocitystar**=*float* **\[required\]**

  Value of the height independent friction velocity (u\*) \[m/s\]\
   Default: *0.32407*

- **row\_wet\_pixel**=*float*

  Row value of the wet pixel

- **column\_wet\_pixel**=*float*

  Column value of the wet pixel

- **row\_dry\_pixel**=*float*

  Row value of the dry pixel

- **column\_dry\_pixel**=*float*

  Column value of the dry pixel

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

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

## DESCRIPTION

*i.eb.hsebal01* will calculate the sensible heat flux map (h0), given both maps of Net Radiation and soil Heat flux (Rn, g0) at instantaneous time, the surface roughness (z0m), a map of the altitude corrected temperature (t0dem), a point data of the frictional velocity (u\*), a value of actual vapour pressure (ea\[KPa\]) and the (x,y) pairs for wet and dry pixels. Full process will need those:

- •

  *i.vi*, *i.albedo*, *r.latlong*, *i.emissivity*

- •

  *i.evapo.potrad* (GRASS Addon)

- •

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

- •

  *i.eb.evapfr*, *i.eb.eta*

(for time integration: *i.evapo.time\_integration*)

*i.eb.hsebal01* performs the computation of *sensible heat flux* \[W/m2\] after Bastiaanssen, 1995 in \[1\], used in this form in 2001 by \[2\]. Implemented in this code in \[3\].

## NOTES

- •

  z0m can be alculated by *i.eb.z0m* or *i.eb.z0m0* (GRASS Addons).

- •

  ea can be calculated with standard meteorological data.\
   eoTmin=0.6108\*EXP(17.27\*Tmin/(Tmin+237.3))\
   eoTmax=0.6108\*EXP(17.27\*Tmax/(Tmax+237.3))\
   ea=(RH/100)/((eoTmin+eoTmax)/2)

- •

  t0dem = surface temperature + (altitude \* 0.627 / 100)

## REFERENCES

\[1\] 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)

\[2\] Chemin Y., Alexandridis T.A., 2001. Improving spatial resolution of ET seasonal for irrigated rice in Zhanghe, China. Asian Journal of Geoinformatics. 5(1):3-11,2004.

\[3\] Alexandridis T.K., Cherif I., Chemin Y., Silleos N.G., Stavrinos E., Zalidis G.C. Integrated methodology for estimating water use in Mediterranean agricultural areas. Remote Sensing. 2009, 1, 445-465. (PDF)

\[4\] 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.soilheatflux,* *i.eb.evapfr*

## AUTHOR

Yann Chemin, International Rice Research Institute, Los Banos, The Philippines.

Contact: Yann Chemin

## SOURCE CODE

Available at: i.eb.hsebal01 source code (history)

Accessed: Monday Feb 24 17:51:32 2025

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