SSURGO and watershed delineation problems

[Jim]

Hello, everyone,

I encountered an error when creating HRUs. See the screenshot below. I am using SSURGO data as input, and according to documentation, the soil lookup table is already built in the program. When I click "create HRU", it throws out this error. I initially used gSSURGO, but I double checked the polygon shp file, which also has a soil MUKEY of 31047821. I am curious if the built-in soil dataset is incomplete? Any thoughts would be greatly appreciated. 

Another questions I have is that the SWAT (TauDEM) delineated watershed is always a bit off with the watershed boundary from NHDPLUS. While it is not off too much, and only in plain areas so I don't think it would affect the simulated discharge too much, I wonder how do we normally treat this difference?

Thank you for your time and inputs.

[Jim]

Still waiting for help. Any thoughts?

[Aida Yahyavi Rahimi]

Did you change the string Mukey to integer in your shape file?

[Andrew Hillman]

A similar error happened to me. I ended up going into the soils shapefile, finding the offending polygon, and manually changing its soil to a neighboring value. Not sure if this is the best way...

[Michael Demanche]

I do not see that muid in the SSURGO data table included with the most recent version of SWAT, which indicates that you are correct that the included database is not complete. I have encountered also encountered other soil types listed in the SSURGO data available on Web Soil Survey which are not included in the built-in soils databases. The database only included MUKEYs with 7 digits (max = 3242432), so any 8 digit MUKEYs like yours won't be there. I've also seen missing 7 digit MUKEYs (specifically for soils in the Caribbean).

I have dealt with this the same way that adhi...@wisc.edu approached the problem, by replacing these soils with nearby, similarly situated soils which I assume to have similar properties. I believe that this could more appropriately be solved by creating a usersoils dataset to include the properties, but I don't have good guidance on how to get the information needed to do so out of the SSURGO data downloaded from WSS. If anyone has guidance on how to do that I would love to hear about it since I'm working on another model for a small watershed where all of the soils are missing from the included database.

Best,

Mike

[Daff gul]

Hello all, 

While I was searching with a missing soil part, can any one please guide me with how did you use the neighbering soil for the missing? did you use interpolation for vector and then rasterize it? 

I appericate your help. 

Thank you.