How to spatially merge two raster files? Failed to execute (Combine).

Question

Hi all,

I'm pretty new to arcGIS Pro so go easy on me.  I'm trying to combine two rasters (.tif format) using the Combine tool in arcGIS Pro 2.4.  The first raster is a map of US land cover at a 30x30m resolution (roughly 8 billion pixels).  The second raster is US counties.   There most common error I get when I try to do this is:

ERROR 010159: Unable to open VAT file of C:\cdl\combine_cdl.tif.

ERROR 010067: Error in executing grid expression.
 Failed to execute (Combine).

I've tried shortening path lengths and making sure I have permissions to the drive.  Also when the tool fails no file, VAT or anything else, is created.  I've also tried moving files inside a local geodatabase with similar results.

Essentially, I'm trying to spatial merge the two files so that I have County FID's associated with land cover.  Next steps involve joining data based on FID and landcover to heatmap.  If there is a better way to go about this please let me know.  I've tried vectoring the land cover raster by doing Raster to Point>Fishnet>Feature to Polygon to get a shapefile to work with, but the 8 Billion values exceeds arcGIS Pro's limit.

Any input is much appreciated.

MasonUnger · Answer

The heat map is the end goal of this project.  Essentially I have a table of dollar amounts by land cover type and county FIPS.  I'm trying to use the 30x30m raster land cover file as the resolution for the dollar amount heat-map.  I was trying to somehow merge my dollar data table with a counties raster file and then merge that to the land cover file so that I would have dollars associated with each land cover pixel for heat-maping.  All land cover dollar values are the same within each county.

I have created a mosiac dataset of the two raster files (counties and land cover) but am struggling how to merge my dollar data to them and how to create a heatmap from this.

DavidPike · Answer

Combine is likely not a good idea as it would generate unique IDs for every land cover /county combination, and be pretty meaningless unless you were doing it within a scripting environment/workflow.

I would really question why you need to do this is the first place, is the heat-map already created? If so - I think back-filling everything into the heatmap is much much harder than recreating it.