i.eb.hsebal01(1)

📦
version 8.4.2 · 8 versions
, in fedora 44

✨ i.eb.hsebal01 ✨

okay bestie, welcome to the GRASS GIS User's Manual 💖 you're looking at i.eb.hsebal01(1) — the little module that does the sensible heat flux iteration SEBAL 01 thing. yes she's niche. yes she's iconic. let's go 🫶

🏷️ 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 — and literally, careful! that's not me being dramatic, that's what the manpage says 💀
  • -c — the Dry/Wet pixel coordinates are given in image projection, not in row/col
  • --overwrite — lets your output files overwrite files that already exist, no cap
  • --help — prints the usage summary, the classic
  • --verbose — verbose module output, she talks a lot
  • --quiet — quiet module output, she says nothing
  • --ui — force launches the GUI dialog, main character energy 🎀

🧸 Parameters

  • netradiation=name [required] — name of the instantaneous net radiation raster map, in [W/m2]
  • soilheatflux=name [required] — name of the instantaneous soil heat flux raster map, in [W/m2]
  • aerodynresistance=name [required] — name of the aerodynamic resistance to heat momentum raster map, in [s/m]
  • temperaturemeansealevel=name [required] — name of the altitude corrected surface temperature raster map, in [K]
  • vapourpressureactual=name [required] — name of the actual vapour pressure (e_act) map, in [KPa]
  • frictionvelocitystar=float [required] — value of the height independent friction velocity (u*), in [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 the output sensible heat flux raster map, in [W/m2]

💅 DESCRIPTION

so i.eb.hsebal01 will calculate the sensible heat flux map (h0) for you, and to do that it needs: both the 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. the full process is gonna want all of these:

  • 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]. 🧚 she's got lore.

📝 NOTES

  • z0m can be alculated by i.eb.z0m or i.eb.z0m0 (GRASS Addons). (yes, "alculated" — that's the original typo and I refuse to gaslight you about it 🙈)
  • 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: Saturday Jan 17 05:41:39 2026

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okay that's the whole page bestie, and for the cute sign-off: this is GRASS 8.4.2 vibes, accessed Saturday Jan 17 05:41:39 2026, manual page i.eb.hsebal01(1) — slay, go compute that heat flux, periodt 💖✨🌸

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