Dear Sirs,
Please I am estimating evapotranspiration (i.evapo.pt) from satellite imagery
using GRASS 7.0.2. However, I have the following concerns that I will be glad
if you could help me solve:
1. I used the relation i.evapo.pt [-z] net_radiation=name
soil_heatflux=name air_temperature=name atmospheric_pressure=name
priestley_taylor_coeff=float output=name
I have image file of the net_radiation, soil_heatflux, air_temperature (Which
I assume is the same as the surface temperature)
The priestley_taylor_coeff constant 1.26 is used.
However, I don't know how to compute or derive a map for the
atmospheric_pressure
Can you help me out with it?
2. I also computing the sensible heat flux ( i.eb.hsebal01)
I have successfully obtained all of the other parameters except the
aerodynresistance.
I will be glad if you can direct me on how to obtain this also
Thank you,
Best regards
Benjamin Ghansah
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International Water Management Institute
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