SEBAL is generally found quite satisfactory and largely accurate in estimating evapotranspiration. It is validated in Spain, Italy, Turkey, Pakistan, India, Sri Lanka, Egypt, Niger and China by Bastiaanssen et al. in 1998, Bastiaanssen and Bos in 1999 and Bastiaanssen et al. in 2003. In Idaho (U.S.) where a good network of electronic agricultural weather stations is in place, SEBAL has been found to perform satisfactory to a great degree. However, if one wants to refine its accuracy, may incorporate extensions as those by Allen et al., (2002), Trezza, (2002) and Tasumi, (2003). Of course, a software is needed to run it. But, equation may also be used as effectively.

SEBAL is generally found quite satisfactory and largely accurate in estimating evapotranspiration. It is validated in Spain, Italy, Turkey, Pakistan, India, Sri Lanka, Egypt, Niger and China by Bastiaanssen et al. in 1998, Bastiaanssen and Bos in 1999 and Bastiaanssen et al. in 2003. In Idaho (U.S.) where a good network of electronic agricultural weather stations is in place, SEBAL has been found to perform satisfactory to a great degree. However, if one wants to refine its accuracy, may incorporate extensions as those by Allen et al., (2002), Trezza, (2002) and Tasumi, (2003). Of course, a software is needed to run it. But, equation may also be used as effectively.

Ilwis

We must have a software or a program for SEBAL model because it is a bit complicated. For its implementation, we have programmed a series of C language program. for more details see "Regionalization of surface flux densities and moisture indicators in composite terrain : a remote sensing approach under clear skies in Mediterranean climates": 

http://library.wur.nl/WebQuery/groenekennis/918192

or

http://edepot.wur.nl/206553

best regards.

Hamimed

Dear Iman

By using remote sensed data (satellite images)  evapotranspiration can be calculated  with the help of Arc GIS software. see this link

http://www.usask.ca/4E24F5CA-F0E8-4DF6-8AFE-3BBE413B5C43/FinalDownload/DownloadId-A83F9AC049E4A05692E62E4E400F85C7/4E24F5CA-F0E8-4DF6-8AFE-3BBE413B5C43/watershed/pdf/Aberdeen_lab_readings_2015/sebal_Manual_2000.pdf

I am here attaching a few papers freely available on the internet. I hope these paper would be considerably helpful in understanding in using SEBAL to calculate Et from remotely sensed images.

thanks Mohammad Firoz Khan i use your information attache met pdf

it is good