i.eb.hsebal01(1grass)

💖 i.eb.hsebal01 — the i.eb.hsebal01 manual page, but make it make sense 💖

okay so bestie, this is a page from the GRASS User's Manual for the module i.eb.hsebal01, and we are gonna get you comfy with it. pull up a chair, grab a snack 🍓, let's go.

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✨ NAME ✨

i.eb.hsebal01 — Computes sensible heat flux iteration SEBAL 01. that's the whole job, she's a one-trick pony and she slays at it 💅

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🎀 KEYWORDS 🎀

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

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🦋 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!). yes the exclamation mark is theirs, they are warning you fr fr 😭
• -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]

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💜 DESCRIPTION 💜

so i.eb.hsebal01 will calculate the sensible heat flux map (h0), and to do that it needs a whole little friend group of inputs: 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. yeah. it's giving "bring the whole group chat" energy 🫶

full process will need 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]. academic lineage? immaculate. 👑

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🌸 NOTES 🌸

• z0m can be calculated 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)

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🌈 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)

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⭐ SEE ALSO ⭐

i.eb.soilheatflux, i.eb.evapfr

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👑 AUTHOR 👑

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

Contact: Yann Chemin

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🔥 SOURCE CODE 🔥

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

Latest change: Thursday Jul 10 08:15:30 2025 in commit: 221d8f7997f68cab15a84350d572e77b6e6bdc37

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© 2003-2026 GRASS Development Team, GRASS 8.5.0 Reference Manual

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and that's the whole thing bestie 🫶 this page lives in GRASS 8.5.0 (GRASS 8.5.0, no cap), it's part of the 2003-2026 GRASS Development Team copyright situation, and the last time anybody touched it was Thursday Jul 10 08:15:30 2025 in commit 221d8f7997f68cab15a84350d572e77b6e6bdc37. go compute some sensible heat flux, you absolute icon 💖✨