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CUAHSI / domain-subsetter

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Subset shapefile is is not georeferenced correctly #36

Open Castronova opened 3 years ago

Castronova commented 3 years ago

https://groups.google.com/a/ucar.edu/g/wrf-hydro_users/c/Te8T6Kuk0cc/m/eVWjx4rUAgAJ?utm_medium=email&utm_source=footer

I am Jongkwan Kim working at the Stevens Institute of Technology. I am trying to apply the WRF-Hydro model over the Northern-east areas of US. I downloaded a WRF-Hydro subset via web site: https://subset.cuahsi.org, but I have an issue with WRF-Hydro preprocessing GIS tool. I was trying to create groundwater inputs using WRF-Hydro preprocessing GIS tool, but it does not work properly with the downloaded geogrid file. The error was from Map Projection within the downloaded geogrid file (geo_em.d0x.nc). I was checking the geogrid file and I came to know that the geogrid file does not include correct coordination information, even though a basin shape file from the same website has a proper coordination system. I displayed subset basin of shape file using ArcGIS and it looks fine. However, when I doing "Create Domain Boundary Shapefile" and "Export grid from GEOGRID file" using WRF-Hydro Preprocessing GIS tool with Geogrid file, I could not display the data sets in the correct position. Please refer to the attached file. My final goal is to generate groundwater input files (GWBASINS.nc and GWBUCKPARM.nc) with WRF-Hydro Preprocessing GIS tool. If you have any questions or suggestions, please feel free to contact me.

Castronova commented 3 years ago

Jongkwan,

You have correctly identified the issue. The CUAHSI group has build a subsetting tool that is incompatible with the WRF-Hydro GIS pre-processing toolsets. This is because the WRF-Hydro GIS tools rely on the 'corner_lats' and 'corner_lons' global attributes in the Geogrid netCDF file in order to properly georeference the file. The CUAHSI subsetter does not re-calculate these coordinates when performing a spatial subset. We simply need to reset these values to the correct corner coordinates for the subset you are using and you will be able to continue using this subsetted Geogrid file with the WRF-Hydro GIS tools. I have code to re-calculate these coordinates, but it is not publicly available. You can send me your geogrid file and I can return the correct coordinate strings.

Thanks,

Kevin