I am working with a DEM that has a bit more data than I actually need. Specifically, even the lowest resolution version is 100ft and I'm trying to reduce it down to 500ft or even 1000ft intervals. I should disclose here that I am pretty much a total noob to both ArcMap and geodata generally at this point.
After digging around on the internet, I think the steps to doing this are:
- Double click on the 100 Foot layer in the table of contents window
- Click on the definition query tab
- Click the Query Builder button
- Create a query like ELEVATION%500 = 0
Unfortunately that doesn't seem to work. Taking a look at the data (right click on 100 Foot layer -> open attribute table) it appears that the elevation for each layer is not simply a number ("0"). Instead, it is a number and the unit of measure that every number in that column uses ("0 ft"). I assume this is what is preventing me from coming up with any matches.
If I am, in fact, on the right path here, is there a way to construct a query that ignores the " ft" portion of the data (or just strips out " ft" from the field)? Alternatively, if I am not, in fact, on the right path here, does anyone have any suggestions for a potentially more fruitful line of inquiry?