i.eb.hsebal01.1grass man page

i.eb.hsebal01 — Computes sensible heat flux iteration SEBAL 01.


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


i.eb.hsebal01 --help
i.eb.hsebal01 [-ac] netradiation=name soilheatflux=name aerodynresistance=name temperaturemeansealevel=name frictionvelocitystar=float vapourpressureactual=float [row_wet_pixel=float] [column_wet_pixel=float] [row_dry_pixel=float] [column_dry_pixel=float] output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]


Automatic wet/dry pixel (careful!)
Dry/Wet pixels coordinates are in image projection, not row/col
Allow output files to overwrite existing files
Print usage summary
Verbose module output
Quiet module output
Force launching GUI dialog


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]
frictionvelocitystar=float [required]
Value of the height independent friction velocity (u*) [m/s]
Default: 0.32407
vapourpressureactual=float [required]
Value of the actual vapour pressure (e_act) [KPa]
Default: 1.511
Row value of the wet pixel
Column value of the wet pixel
Row value of the dry pixel
Column value of the dry pixel
output=name [required]
Name for output sensible heat flux raster map [W/m2]


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].


z0m can be alculated by i.eb.z0m or i.eb.z0m0 (GRASS Addons).
ea can be calculated with standard meteorological data.
t0dem = surface temperature + (altitude * 0.627 / 100)

See Also

i.eb.soilheatflux, i.eb.hsebal01, i.eb.evapfr


[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)


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

Contact: Yann Chemin

Last changed: $Date: 2015-01-25 18:56:33 +0100 (Sun, 25 Jan 2015) $

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