## DESCRIPTION

i.eb.h_sebal01 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, i.latlong, i.emissivity
- i.evapo.potrad
- i.eb.netrad, i.eb.soilheatflux, i.eb.h_sebal01
- i.eb.evapfr, i.eb.eta

(for time integration: i.evapo.time_integration)

i.eb.h_sebal01 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].

## NOTES

- z0m can be alculated by i.eb.z0m or i.eb.z0m0 (grass-addons).
- ea can be calculated with standard meteorological data.
  eoTmin=0.6108*EXP(17.27*Tmin/(Tmin+237.3))
  eoTmax=0.6108*EXP(17.27*Tmax/(Tmax+237.3))
  ea=(RH/100)/((eoTmin+eoTmax)/2)
- t0dem = surface temperature + (altitude * 0.627 / 100)

## SEE ALSO

i.eb.soilheatflux, i.eb.h_sebal01, i.eb.evapfr

## REFERENCES

[1] Bastiaanssen, W.G.M., 1995. Estimation of Land surface paramters by remote sensing under clear-sky conditions. PhD thesis, Wageningen University, Wageningen, The Netherlands.

[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, 1(3):445-465, 2009.

## AUTHORS

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

Contact: Yann Chemin

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