1i.eb.hsebal01(1)            GRASS GIS User's Manual           i.eb.hsebal01(1)
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NAME

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

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

12       i.eb.hsebal01
13       i.eb.hsebal01 --help
14       i.eb.hsebal01  [-ac]  netradiation=name soilheatflux=name aerodynresis‐
15       tance=name temperaturemeansealevel=name vapourpressureactual=name fric‐
16       tionvelocitystar=float           [row_wet_pixel=float]            [col‐
17       umn_wet_pixel=float]   [row_dry_pixel=float]   [column_dry_pixel=float]
18       output=name  [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]
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20   Flags:
21       -a
22           Automatic wet/dry pixel (careful!)
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24       -c
25           Dry/Wet pixels coordinates are in image projection, not row/col
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27       --overwrite
28           Allow output files to overwrite existing files
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30       --help
31           Print usage summary
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33       --verbose
34           Verbose module output
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36       --quiet
37           Quiet module output
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39       --ui
40           Force launching GUI dialog
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42   Parameters:
43       netradiation=name [required]
44           Name of instantaneous net radiation raster map [W/m2]
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46       soilheatflux=name [required]
47           Name of instantaneous soil heat flux raster map [W/m2]
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49       aerodynresistance=name [required]
50           Name of aerodynamic resistance to heat momentum raster map [s/m]
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52       temperaturemeansealevel=name [required]
53           Name of altitude corrected surface temperature raster map [K]
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55       vapourpressureactual=name [required]
56           Name of the actual vapour pressure (e_act) map [KPa]
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58       frictionvelocitystar=float [required]
59           Value of the height independent friction velocity (u*) [m/s]
60           Default: 0.32407
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62       row_wet_pixel=float
63           Row value of the wet pixel
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65       column_wet_pixel=float
66           Column value of the wet pixel
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68       row_dry_pixel=float
69           Row value of the dry pixel
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71       column_dry_pixel=float
72           Column value of the dry pixel
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74       output=name [required]
75           Name for output sensible heat flux raster map [W/m2]
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DESCRIPTION

78       i.eb.hsebal01  will  calculate  the  sensible heat flux map (h0), given
79       both maps of Net Radiation and soil Heat flux (Rn, g0) at instantaneous
80       time, the surface roughness (z0m), a map of the altitude corrected tem‐
81       perature (t0dem), a point data of the frictional velocity (u*), a value
82       of actual vapour pressure (ea[KPa]) and the (x,y) pairs for wet and dry
83       pixels.  Full process will need those:
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85           •   i.vi, i.albedo, r.latlong, i.emissivity
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87           •   i.evapo.potrad (GRASS Addon)
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89           •   i.eb.netrad, i.eb.soilheatflux, i.eb.hsebal01
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91           •   i.eb.evapfr, i.eb.eta
92       (for time integration: i.evapo.time_integration)
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94       i.eb.hsebal01 performs the computation of sensible heat flux [W/m2] af‐
95       ter Bastiaanssen, 1995 in [1], used in this form in 2001 by [2]. Imple‐
96       mented in this code in [3].
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NOTES

99           •   z0m can be alculated by i.eb.z0m or i.eb.z0m0 (GRASS Addons).
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101           •   ea can be calculated with standard meteorological data.
102               eoTmin=0.6108*EXP(17.27*Tmin/(Tmin+237.3))
103               eoTmax=0.6108*EXP(17.27*Tmax/(Tmax+237.3))
104               ea=(RH/100)/((eoTmin+eoTmax)/2)
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106           •   t0dem = surface temperature + (altitude * 0.627 / 100)
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REFERENCES

109       [1] Bastiaanssen, W.G.M., 1995.  Estimation of Land surface  parameters
110       by  remote  sensing  under clear-sky conditions. PhD thesis, Wageningen
111       University, Wageningen, The Netherlands.  (PDF)
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113       [2] Chemin Y., Alexandridis T.A., 2001. Improving spatial resolution of
114       ET  seasonal  for  irrigated  rice  in Zhanghe, China. Asian Journal of
115       Geoinformatics. 5(1):3-11,2004.
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117       [3] Alexandridis T.K., Cherif I., Chemin Y.,  Silleos  N.G.,  Stavrinos
118       E.,  Zalidis  G.C.  Integrated  methodology for estimating water use in
119       Mediterranean agricultural areas. Remote  Sensing.  2009,  1,  445-465.
120       (PDF)
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122       [4]  Chemin, Y., 2012.  A Distributed Benchmarking Framework for Actual
123       ET Models, in: Irmak, A. (Ed.), Evapotranspiration - Remote Sensing and
124       Modeling. InTech.  (PDF)
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SEE ALSO

127        i.eb.soilheatflux, i.eb.evapfr
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AUTHOR

130       Yann  Chemin,  International  Rice  Research  Institute, Los Banos, The
131       Philippines.
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133       Contact: Yann Chemin
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SOURCE CODE

136       Available at: i.eb.hsebal01 source code (history)
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138       Accessed: Saturday Jan 21 21:16:36 2023
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140       Main index | Imagery index | Topics index | Keywords index |  Graphical
141       index | Full index
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143       © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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147GRASS 8.2.1                                                   i.eb.hsebal01(1)