I'll try to address your issues in a single post.
>I am at step 6, writing SWAT input files, but I cannot select.
>Although I have delineation, discretization and parametrization, and swat ppt file.
Once a parameterization is complete, the ability to select a watershed in the Write SWAT Input Files step should be available. If it is not available, the reason is because the parameterization step failed, which is what your next message seems to indicate. Once a parameterization is complete without an error popping up like "Weighting the soil intersection failed" or being written to the textbox in the Parameterizer form with the message "Land Cover status: failed" or "Soil status: failed", then a watershed should be selectable to write model input files for.
>okay, I get it, it said parameterization completed.>But was also showing soil status: FAILED.
>how can I fix this?
>Also, I obtained the soil data from FAO. ESRI file formate but in the video of AGWA support on youtube I saw how Microsoft >access was used but there is a loophole in my case that I didn't did anything like that since I didn't receive any Microsoft >access file.
An Access file is used as the soils database when using SSURGO or STATSGO2 soil data within the U.S. When using FAO soils, an Access database is not used because the FAO soils look-up tables are included in the AGWA\datafiles\fao\ directory.
>Can you tell me why this is happening, and how can I fix this? It would be a huge help.
We may need to iterate a few times to solve this, or if you can send me your input data I can take a look at it myself. To help troubleshoot, in the ArcMap document you're working in, open the Results window accessed via the Geoprocessing menu on the menu bar of ArcMap. After the parameterization has failed, see if there are any entries in the Geoprocessing window that also failed, indicated by a red X. Also, send me the the errors.txt file, which is located in the same directory as your ArcMap document for the project.
If you can send the input data, I will need the geodatabase containing the delineation and discretization, as well as your land cover raster.
>For a study area outside the US, Is it correct to use this landcover lookup database?