1i.eb.hsebal01(1)            GRASS GIS User's Manual           i.eb.hsebal01(1)
2
3
4

NAME

6       i.eb.hsebal01  - Computes sensible heat flux iteration SEBAL 01.
7

KEYWORDS

9       imagery, energy balance, soil moisture, evaporative fraction, SEBAL
10

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]
19
20   Flags:
21       -a
22           Automatic wet/dry pixel (careful!)
23
24       -c
25           Dry/Wet pixels coordinates are in image projection, not row/col
26
27       --overwrite
28           Allow output files to overwrite existing files
29
30       --help
31           Print usage summary
32
33       --verbose
34           Verbose module output
35
36       --quiet
37           Quiet module output
38
39       --ui
40           Force launching GUI dialog
41
42   Parameters:
43       netradiation=name [required]
44           Name of instantaneous net radiation raster map [W/m2]
45
46       soilheatflux=name [required]
47           Name of instantaneous soil heat flux raster map [W/m2]
48
49       aerodynresistance=name [required]
50           Name of aerodynamic resistance to heat momentum raster map [s/m]
51
52       temperaturemeansealevel=name [required]
53           Name of altitude corrected surface temperature raster map [K]
54
55       vapourpressureactual=name [required]
56           Name of the actual vapour pressure (e_act) map [KPa]
57
58       frictionvelocitystar=float [required]
59           Value of the height independent friction velocity (u*) [m/s]
60           Default: 0.32407
61
62       row_wet_pixel=float
63           Row value of the wet pixel
64
65       column_wet_pixel=float
66           Column value of the wet pixel
67
68       row_dry_pixel=float
69           Row value of the dry pixel
70
71       column_dry_pixel=float
72           Column value of the dry pixel
73
74       output=name [required]
75           Name for output sensible heat flux raster map [W/m2]
76

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:
84
85           ·   i.vi, i.albedo, r.latlong, i.emissivity
86
87           ·   i.evapo.potrad (GRASS Addon)
88
89           ·   i.eb.netrad, i.eb.soilheatflux, i.eb.hsebal01
90
91           ·   i.eb.evapfr, i.eb.eta
92       (for time integration: i.evapo.time_integration)
93
94       i.eb.hsebal01 performs the computation of  sensible  heat  flux  [W/m2]
95       after  Bastiaanssen,  1995  in  [1],  used in this form in 2001 by [2].
96       Implemented in this code in [3].
97

NOTES

99           ·   z0m can be alculated by i.eb.z0m or i.eb.z0m0 (GRASS Addons).
100
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)
105
106           ·   t0dem = surface temperature + (altitude * 0.627 / 100)
107

SEE ALSO

109        i.eb.soilheatflux, i.eb.evapfr
110

REFERENCES

112       [1] Bastiaanssen, W.G.M., 1995.  Estimation of Land surface  parameters
113       by  remote  sensing  under clear-sky conditions. PhD thesis, Wageningen
114       University, Wageningen, The Netherlands.  (PDF)
115
116       [2] Chemin Y., Alexandridis T.A., 2001. Improving spatial resolution of
117       ET  seasonal  for  irrigated  rice  in Zhanghe, China. Asian Journal of
118       Geoinformatics. 5(1):3-11,2004.
119
120       [3] Alexandridis T.K., Cherif I., Chemin Y.,  Silleos  N.G.,  Stavrinos
121       E.,  Zalidis  G.C.  Integrated  methodology for estimating water use in
122       Mediterranean agricultural areas. Remote  Sensing.  2009,  1,  445-465.
123       (PDF)
124
125       [4]  Chemin, Y., 2012.  A Distributed Benchmarking Framework for Actual
126       ET Models, in: Irmak, A. (Ed.), Evapotranspiration - Remote Sensing and
127       Modeling. InTech.  (PDF)
128

AUTHORS

130       Yann  Chemin,  International  Rice  Research  Institute, Los Banos, The
131       Philippines.
132
133       Contact: Yann Chemin
134

SOURCE CODE

136       Available at: i.eb.hsebal01 source code (history)
137
138       Main index | Imagery index | Topics index | Keywords index |  Graphical
139       index | Full index
140
141       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
142
143
144
145GRASS 7.8.5                                                   i.eb.hsebal01(1)
Impressum