Behzad,

I think that Prof. Ana Barros (Duke University) has worked (or is still
working) in the same direction as yours. You may contact her through
the following e-address:

ana.barros@...

You may also wish to contact Prof. Dirk Raes (one of the co-authors of
the FAO-56 report), who could give you an additional piece of advice,
through the following e-address:

dirk.raes@...

Furthermore, I advise you to get the following publications where you
may obtain detailed information about references suggested in earlier
messages by other colleagues, such as the ASCE 70 handbook, the FAO-56
report, the FAO-24 report, as well as other relevant and useful set of
references.

Vázquez R. F. and J. Feyen, 2004. Potential Evapotranspiration for the
Distributed Modeling of Belgian Catchments. (ASCE) Journal of
Irrigation and Drainage Engineering, 130(1): 1-8.

Vázquez R. F. and J. Feyen, 2003. Effect of potential
evapotranspiration estimates on effective parameters and performance of
the MIKE SHE-code applied to a medium-size catchment. Journal of
Hydrology, 270(4): 309-327.

Success with your investigation.

Cordially,

--
Raul Vazquez Z, Ph.D. MSc. Eng.
Katholieke Universiteit Leuven
Department of Civil Engineering - Hydraulics Laboratory
Kasteelpark Arenberg 40
B-3001 Leuven (Belgium)
Tel.: +32 16 32 16 63 - 32 16 56
Fax: +32 16 32 19 89
URL: http://www.kuleuven.ac.be/hydr/Index.html
http://www.geocities.com/raulito_vz/


Quoting behzad@...:

> Dear friends,
> I am looking for (mathematical) models for evapotranspiration rate.
> A literature review regarding evapotranspiration methods also is
> useful.
> In reality, I need to develop one model for evapotranspiration rate
> of trees which should be related to soil suction and properties.
> Would you please if you know any useful references let me know?
> Regards,
> Behzad