i.eb.hsebal01(1grass)

1i.eb.hsebal01(1)              Grass 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    frictionvelocitystar=float
16       vapourpressureactual=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       frictionvelocitystar=float [required]
56           Value of the height independent friction velocity (u*) [m/s]
57           Default: 0.32407
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59       vapourpressureactual=float [required]
60           Value of the actual vapour pressure (e_act) [KPa]
61           Default: 1.511
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63       row_wet_pixel=float
64           Row value of the wet pixel
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66       column_wet_pixel=float
67           Column value of the wet pixel
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69       row_dry_pixel=float
70           Row value of the dry pixel
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72       column_dry_pixel=float
73           Column value of the dry pixel
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75       output=name [required]
76           Name for output sensible heat flux raster map [W/m2]
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DESCRIPTION

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

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

113       [1] Bastiaanssen, W.G.M., 1995.  Estimation of Land surface  parameters
114       by  remote  sensing  under clear-sky conditions. PhD thesis, Wageningen
115       University, Wageningen, The Netherlands.  (PDF)
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117       [2] Chemin Y., Alexandridis T.A., 2001. Improving spatial resolution of
118       ET  seasonal  for  irrigated  rice  in Zhanghe, China. Asian Journal of
119       Geoinformatics. 5(1):3-11,2004.
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121       [3] Alexandridis T.K., Cherif I., Chemin Y.,  Silleos  N.G.,  Stavrinos
122       E.,  Zalidis  G.C.  Integrated  methodology for estimating water use in
123       Mediterranean agricultural areas. Remote  Sensing.  2009,  1,  445-465.
124       (PDF)
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126       [4]  Chemin, Y., 2012.  A Distributed Benchmarking Framework for Actual
127       ET Models, in: Irmak, A. (Ed.), Evapotranspiration - Remote Sensing and
128       Modeling. InTech.  (PDF)
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AUTHORS

131       Yann  Chemin,  International  Rice  Research  Institute, Los Banos, The
132       Philippines.
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134       Contact: Yann Chemin
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136       Last changed: $Date: 2015-01-25 18:55:23 +0100 (Sun, 25 Jan 2015) $
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SOURCE CODE

139       Available at: i.eb.hsebal01 source code (history)
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141       Main index | Imagery index | Topics index | Keywords index |  Graphical
142       index | Full index
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144       © 2003-2019 GRASS Development Team, GRASS GIS 7.4.4 Reference Manual
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148GRASS 7.4.4                                                   i.eb.hsebal01(1)