Use NHD dataset to delineate watershed

[Haley]

Hello everyone,

I am trying to use the option of having a predefined watershed (NHDPlus) for delineation. However, the final step I am struggling with is assigning downstream channel link numbers for the NHD reach shapefile. It seems these should exist in the dataset but I am having trouble finding them. Is there a more specific/comprehensive tutorial on how to use the NHDPlus data to set up a SWAT+ watershed?

Thanks in advance,

Haley

[Haley]

Update: I realize now you have to download the NHD hydrography dataset-- which contains the information needed to prepare the shapefiles for SWAT+. However, there are a lot of issues/ inconsistencies within the NHD data (e.g., subbasin having 2 outlets) that QSWAT+ is struggling to make sense. Does anyone have any recommendations for how to deal with inconsistencies in the NHD data to prepare the data for SWAT+?

Thanks in advance,

Haley

[natalja....@gmail.com]

Hello Haley,

You will have to go thru a lot of manual "cleaning" of the NHD+ data for it to be usable via the interfaces. If you are working on a particular HUC8 watershed: we have the entire US setup with SWAT+. See here : 

• DOI: 
• 10.1111/1752-1688.13056 and here: 

• DOI: 
• 10.1016/j.agsy.2023.103695

We can share whichever HUC8 you want. All were build on the NHD+ data (which was severely cleaned).

Best,

Natalja

[Mohamed Aboelnour]

Hi Natalja,

This thread is extremely helpful and confirms what I have been encountering with the NHDPlus data. I am currently trying to delineate a HUC8 watershed using predefined subbasins and streams, but I keep running into errors during the delineation step, likely due to inconsistencies in the raw NHD topology. I am working specifically on HUC8 04050001.

If it would be possible to share the SWAT+-ready subbasins and stream network you prepared for this HUC8, I would greatly appreciate it. Having a vetted version would help me move past these delineation issues and ensure the setup follows established best practices.

Thank you again for offering to share these datasets, they are very informative.

Moh

[Mohamed Aboelnour]

Hi Natalja,

This thread is extremely helpful and confirms what I have been encountering with the NHDPlus data. I am currently trying to delineate a HUC8 watershed using predefined subbasins and streams, but I keep running into errors during the delineation step, likely due to inconsistencies in the raw NHD topology. I am working specifically on HUC8 04050001.

If it would be possible to share the SWAT+-ready subbasins and stream network you prepared for this HUC8, I would greatly appreciate it. Having a vetted version would help me move past these delineation issues and ensure the setup follows established best practices.

Thank you again for offering to share these datasets, they are very informative.

Moh

On Wednesday, December 13, 2023 at 1:18:59 PM UTC-5 natalja....@gmail.com wrote: