I have three layers I need to try match up at the borders. This is not a projection problem, all layers are projected to Albers NAD83. The base layer (Green) is 30m DEM, with a US boundaries layer on top of the DEM and finally a polygon "layer of interest" on top (Red). As you can see in the figure below, none of these layers match up at the borders.

What is the best way to get these layers to match up in ArcMap 10.1? This is mainly for aesthetics, as I have it the red layer is transparent and it just looks bad.


So figure 2 (bottom) is what I have done thus far. (Note: I have changed the colors around in figure 1 just to make the different layers easier to distinguish for you all.)

As you can see, the problem with the layers lining up isn't all that bad at this scale.. but I'm picky like that. Figure 1 is zoomed in to an area on the coast of South Carolina (apologies for no scale bar).

@Kevin, the state boundaries were requested because this project spans many states and the hillshade (while not required) was also requested and adds some pizaz.

Thanks everyone for comments so far. enter image description here

enter image description here

  • 6
    They appear to all have been produced with a different resolution/scale in which case I don't think you will get them to line up
    – user681
    Aug 28, 2013 at 17:06
  • 5
    @DanPatterson is correct. Also, these (apparent) coastline features are likely ephemeral. Even datasets produced at the same resolution may have been produced at different dates and/or have been digitized from different basemaps. If is essential for your application that these layers correspond better, you could try calculating the envelope of the higher-resolution layer, or dissolving/generalizing a copy of it.
    – Arthur
    Aug 28, 2013 at 17:29
  • I find this confusing because the DEM is raster and would have a rectangular edge. (perhaps the data values are null or out of scale) the state boundary could certainly be moved (not optimal for accuracy unless you find a state_dtl_bndy) It all comes down to the third LOI. If it is vector based then directions can be given to help you. please edit the original question with more information.
    – Brad Nesom
    Aug 28, 2013 at 20:39
  • The DEM may have had pixels set to NoData, or some uniform value like 0, in the water, and the "DEM" vector is a boundary of those pixels. If you look closely you can see rectangular edges on that boundary: probably artifacts of a raster-to-vector conversion.
    – user3461
    Aug 28, 2013 at 23:57
  • The DEM is 30m NED with ocean areas set to no data. The LOI is a vector.
    – derelict
    Aug 29, 2013 at 17:48

1 Answer 1


It seems to me that your question is really about cartography/design. You've got three datasets that were produced at different scales/resolutions for different purposes and you need to get them to work together to convey some information.

I would use the DEM to show the landmass areas, perhaps as a shaded relief/hillshade and change the state boundary to look like a boundary, so it's more clear from the outset what it is. Then for your layer I would experiment with using a pattern fill with an empty background to indicate which portions of the landmass if covers. Also, consider if you really need all three layers. Are they all relevant to the data your map is intended to convey? If the administrative extent of the state boundary isn't relevant to what you're trying to show, maybe you can pull it without consequence. What about the DEM?

My point is that there isn't really one answer to this. You're struggling with a fundamental challenge of GIS/cartography. The good news is - you've already done the hard part. Your data is all in the right place. Making it look nice is now a wholly different problem.

If you're feeling like trying something really different - perhaps you could turn your layer into a raster and then try this: http://blogs.esri.com/esri/arcgis/2012/03/08/an-alternative-to-overlaying-layer-tints-on-hillshades/

That might make an interesting way to show the landmass and the variable(s) represented by your layer without having to deal with the washout from a transparent polygon.

  • Thanks for the comments, I'll probably settle with what I have.. for now.
    – derelict
    Aug 29, 2013 at 19:20

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