I have this big land use map. I extracted shapes associated with mountains so that I can improve the classification (for example, I corrected clouds in the mountains to be forest, among other things). Now I want to flatten the two layers with the extracted layer over-writing the info on the original map. I tried union, merge and other things, but the info I want overwritten is still there (ex. the clouds are still there).

I checked for instance the result of the union and I saw that the all the data columns of both shapefiles were appended together. The effect I want is for the data of the top layer to replace the data of the lower layer. In Photoshop, this is just basic flattening (i.e. pixel value of higher layer replaces all pixel values of underlying layers).

  • Have you tried the Update tool (requires an Advanced license)? – GISGe Jun 17 '14 at 10:51
  • Unfortunately, I don't have an Advanced license. – Nomisugi Jun 17 '14 at 10:53
  • I think the tool that you would ideally use is Erase but this requires an Advanced license. However, with a Basic license you can easily achieve the same result. gis.stackexchange.com/questions/80376/… is a Q&A where how to do this has been mentioned. – PolyGeo Jun 17 '14 at 11:04
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    If you remember the selection rules you used to make the subsets you can simply save the non-exported rows to an additional file and append that to the edited subsets. – Vince Jun 17 '14 at 11:11
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    Is the original land use map in raster format, or polygons? – Erica Jun 17 '14 at 11:41

If you don't have an Advanced license:

  1. Union the old and the updated polygons.
  2. Select the features having FIDs from both input feature classes and delete them.
  3. Merge the updated feature class with the output of the previous step.

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