HEC-Geo HMS Curve number grid problem

Question

Hi, i'm trying to create a curve number grid and have followed this guide (https://web.ics.purdue.edu/~vmerwade/education/cngrid.pdf), however i'm at the last stage and when i go to create the curve number grid it just runs and doesnt finish. Both the HydroDEM and Soil/Land use polygon are in the same coordinate system (British National Grid). I tried to clip the DEM to the Soil/LU polygon by converting the polygon to raster then using Clip, however the DEM doesn't Clip and stays the same. I had similar problems with Flow Accumulation weight grid, however clipping the weight grid worked in that instance. I'm not sure if the DEM not being the same exent would make a difference but does anyone have an idea to what is wrong?

Thanks

DanPatterson_Retired · Answer

glad it worked

MS10 · Answer

Hi,I imported the Soil /LU polygon and DEM into the Geodatabase that contained the CN Look up table and it seems to have worked. Thanks again.

DanPatterson_Retired · Answer

the extents of the files are indeed important.  You need to examine and report those.  Also when using the clip tool in Arctoolbox, the environments (bottom of every tool dialog) need to be explicitly set regarding cell size, the extent and snap raster if appropriate.