Zonal statistics - empty table

[Shannon Wing Belmont]

Question:
So I'm attempting to do the Zonal Statistics as a table for the landcover layer.  As first input I use the study area file, then the second input the landcover file.  I calculate all statistics and that produces an empty table.  If I change the zone field from Id to FID I can at least get something in the table, but I'm not sure how useful it is.  My majority value is 62 which corresponds with Inter Mountain Sagebrush Steppe.  Just by looking at the map, visually I don't think this is the most dominant land cover within the study area.  Am I missing a step or should I trust my table?

Response:

1. Don't trust ArcGIS (i.e. your table).
You are right to evaluate the results and question the emptiness of the table.
Your troubleshooting idea (changing ID to FID) is a sound one.
Good to try to make sense of the values output.

I think your output sounds reasonable. Looks to me like value 62 is heavily dominating the eastern portion of the polygon area and plays a large role in the western portion. I think you are right on.

2. If you aren't in the habit of using the Tool Help, get in the habit.With that side window open, if you click on the different names of the tool parameters, the tool help updates to describe what each thing means.

[Ben]

I'm having even worse trouble with this. I've run this at least a 15 times, now, changing every setting I can think of that might matter, and the table still comes up empty. I've changed the zone field, toggled the 'ignore no data' box'. selected different statistics other than "ALL, "converted the study area polygon to a raster with an attribute table for input, messed with the raster settings in the environments dialog, and whatever else the tool help file indicated. 

I'm kind of at a loss. I bet what's actually wrong is something silly and simple. Any ideas? 

Ben

[Ben]

It may be worth adding that I'm having a somewhat similar problem with the zonal statistics. No matter what I do, I get a block 191 pixels big, that's coincidentally  in the shape of Utah:

[Shannon Wing Belmont]

Wow, Ben. This is sounding like a good old ArcGIS haunting.

Have you done the first rule of troubleshooting? Save your project, quit arcmap, start a new empty project, add only the file(s) you need, rerun the tools?

The key is to get out of the ArcMap project you've been working in. You need a clean slate.

Your efforts to troubleshoot are all sound. Changing the value field to FID should do the trick.

You might also try unzipping the downloaded folder again in case something glitched out during the extraction process.

If that doesn't work, I can send you a different version of the data and see if we can get around whatever glitch is holding you back. Stay in touch.

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Shannon Belmont

Quinney College of Natural Resources
Utah State University
5210 Old Main Hill
Logan, UT 84322-5210