.TH i.eb.hsebal01 1grass "" "GRASS 7.8.5" "GRASS GIS User's Manual"
.SH NAME
\fI\fBi.eb.hsebal01\fR\fR  \- Computes sensible heat flux iteration SEBAL 01.
.SH KEYWORDS
imagery, energy balance, soil moisture, evaporative fraction, SEBAL
.SH SYNOPSIS
\fBi.eb.hsebal01\fR
.br
\fBi.eb.hsebal01 \-\-help\fR
.br
\fBi.eb.hsebal01\fR [\-\fBac\fR] \fBnetradiation\fR=\fIname\fR \fBsoilheatflux\fR=\fIname\fR \fBaerodynresistance\fR=\fIname\fR \fBtemperaturemeansealevel\fR=\fIname\fR \fBvapourpressureactual\fR=\fIname\fR \fBfrictionvelocitystar\fR=\fIfloat\fR  [\fBrow_wet_pixel\fR=\fIfloat\fR]   [\fBcolumn_wet_pixel\fR=\fIfloat\fR]   [\fBrow_dry_pixel\fR=\fIfloat\fR]   [\fBcolumn_dry_pixel\fR=\fIfloat\fR]  \fBoutput\fR=\fIname\fR  [\-\-\fBoverwrite\fR]  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-a\fR" 4m
.br
Automatic wet/dry pixel (careful!)
.IP "\fB\-c\fR" 4m
.br
Dry/Wet pixels coordinates are in image projection, not row/col
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-help\fR" 4m
.br
Print usage summary
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.IP "\fB\-\-ui\fR" 4m
.br
Force launching GUI dialog
.SS Parameters:
.IP "\fBnetradiation\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of instantaneous net radiation raster map [W/m2]
.IP "\fBsoilheatflux\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of instantaneous soil heat flux raster map [W/m2]
.IP "\fBaerodynresistance\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of aerodynamic resistance to heat momentum raster map [s/m]
.IP "\fBtemperaturemeansealevel\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of altitude corrected surface temperature raster map [K]
.IP "\fBvapourpressureactual\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of the actual vapour pressure (e_act) map [KPa]
.IP "\fBfrictionvelocitystar\fR=\fIfloat\fR \fB[required]\fR" 4m
.br
Value of the height independent friction velocity (u*) [m/s]
.br
Default: \fI0.32407\fR
.IP "\fBrow_wet_pixel\fR=\fIfloat\fR" 4m
.br
Row value of the wet pixel
.IP "\fBcolumn_wet_pixel\fR=\fIfloat\fR" 4m
.br
Column value of the wet pixel
.IP "\fBrow_dry_pixel\fR=\fIfloat\fR" 4m
.br
Row value of the dry pixel
.IP "\fBcolumn_dry_pixel\fR=\fIfloat\fR" 4m
.br
Column value of the dry pixel
.IP "\fBoutput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name for output sensible heat flux raster map [W/m2]
.SH DESCRIPTION
\fIi.eb.hsebal01\fR 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:
.RS 4n
.IP \(bu 4n
\fIi.vi\fR, \fIi.albedo\fR, \fIr.latlong\fR, \fIi.emissivity\fR
.IP \(bu 4n
\fIi.evapo.potrad\fR (GRASS Addon)
.IP \(bu 4n
\fIi.eb.netrad\fR, \fIi.eb.soilheatflux\fR, \fIi.eb.hsebal01\fR
.IP \(bu 4n
\fIi.eb.evapfr\fR, \fIi.eb.eta\fR
.RE
(for time integration: \fIi.evapo.time_integration\fR)
.PP
\fIi.eb.hsebal01\fR performs the computation of \fIsensible heat flux\fR
[W/m2] after Bastiaanssen, 1995 in [1], used in this form in 2001 by [2]. Implemented
in this code in [3].
.SH NOTES
.RS 4n
.IP \(bu 4n
z0m can be alculated by \fIi.eb.z0m\fR or \fIi.eb.z0m0\fR (GRASS Addons).
.IP \(bu 4n
ea can be calculated with standard meteorological data.
.br
eoTmin=0.6108*EXP(17.27*Tmin/(Tmin+237.3))
.br
eoTmax=0.6108*EXP(17.27*Tmax/(Tmax+237.3))
.br
ea=(RH/100)/((eoTmin+eoTmax)/2)
.IP \(bu 4n
t0dem = surface temperature + (altitude * 0.627 / 100)
.RE
.SH SEE ALSO
\fI
i.eb.soilheatflux,
i.eb.evapfr
\fR
.SH REFERENCES
.PP
[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)
.PP
[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.
.PP
[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)
.PP
[4] Chemin, Y., 2012.
A Distributed Benchmarking Framework for Actual ET Models,
in: Irmak, A. (Ed.), Evapotranspiration \- Remote Sensing and Modeling. InTech.
(PDF)
.SH AUTHORS
Yann Chemin, International Rice Research Institute, Los Banos, The
Philippines.
.PP
Contact: Yann Chemin
.SH SOURCE CODE
.PP
Available at: i.eb.hsebal01 source code (history)
.PP
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.PP
© 2003\-2020
GRASS Development Team,
GRASS GIS 7.8.5 Reference Manual