4

I'm working with ArcGIS and the following image is showing the polygons that I have in my shapefile. The seleted polygon should actually be this selected one + the blank area right below it.

This blank area has no attribute related to it. I mean, it isn't a polygon. It is just a hole in my shapefile.

Eventually, how do I use this shape to be part of my selected polygon?

I forgot to mention, but I have many holes like this in my shapefile. I'm wondering if there is a faster way of filling these holes than digitizing all those individual polygons!

Poligon Missing area

  • 1
    For further reading, you could check the ArcGIS Help Guide for Filling in holes in polygons – Joseph Jun 29 '15 at 15:09
  • If you don't want to add it to your existing polygon, per @Brad_Nesom's answer, you're kind of out of luck. Since there is nothing there, you can't add it to anything. You could create a new polygon for the hole and set it's symbology to No Color and border width to 0, then select both. This works to keep your display as is, but may not be appropriate for the rest of your workflow. – recurvata Jun 29 '15 at 15:11
  • The other option is to edit existing polygon but this method is much easier unless you know what you are doing.. i.e. delete existing vertices, and add vertices along the new edge... – Brad Nesom Jun 29 '15 at 15:36
  • automating this would take some more advanced knowledge and the production editing tools... desktop.arcgis.com/en/desktop/latest/guide-books/extensions/… – Brad Nesom Jun 29 '15 at 15:43
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    I feel like you should be able to create a big polygon that covers the area of interest, and union the input fc with it. That should create polys in the gap areas which could then be merged with neighbors, etc. Can someone more knowledgeable say whether this is a valid workflow? – mkennedy Jun 29 '15 at 16:41
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Depend what means 'many holes', but if it's not hundreds/thousands you can always use Auto Complete polygon tool. All you have to do is start edit session, select the tool, draw the line across a hole and merge created polygons to required polygon. It is better than digitising and Trace but still semi manual…
see screenshots:

Select Auto complete tool and Draw a line across the hole enter image description here Double click to finish enter image description here Select polygon you want to merge newly created polygons enter image description here and use Merge tool (under edit toolbar) enter image description here

  • 2
    ChrisL If you don't go all the way across the gap it will autofill and no double polygon to select for merge. – Brad Nesom Jun 29 '15 at 15:59
  • Hey @ChrisL, this is exactly what I was looking for! Thank you so much for giving me the instructions! =D – Matt_Geo Jun 29 '15 at 16:04
2

You can start editing on the selected polygon and snap the new vertices to the boundaries of the polygons surrounding the hole, effectively increasing the "selected polygon" to the area contained by the hole. You will also have recalculate the area in the attribute table to update the entire area. This can be accomplished using the tools in the editor toolbar, specifically the trace tool.

enter image description here

The trace tool is the third from the left.

  • Thank you so much for introducing me the Trace tool!I did not know about it! It helped me a lot! =D – Matt_Geo Jun 29 '15 at 15:58
2

This sort of problem is what the topology tool was made for:

  • Create a topology for this layer using the "No Gaps" rule
  • Validate the topology
  • Add it the TOC

Use the fix topology tool to Create Features. You can do this one by one or all at once.

1

I would

  1. edit the polygon layer.
  2. trace the missing polygon boundary.
  3. merge the selected polygon and the newly created one.

screenshots

  1. edit
    edit
  2. Trace
    create a new feature using the autocomplete polygon tool.
    Create feature
    Autocomplete @ChrisL is correct...
    You can simply draw a line crossing one of the edges (justone single segment from one existing polygon into the missing hole and double click. no tracing needed.
    Then merge them
    single line

EDIT: I am leaving the trace instructions here. It helps to know the old way. Switch to tracing mode (instead of line)
Trace
select an existing polygon edge on the missing polygon edge.
Begin tracing...
Trace until you get to an intersection and single click the exact intersection point (zoom in with the wheel mouse).
intersection
Pick the next edge to begin tracing it.
trace 2
Continue until you have returned to the beginning point. Stop one vertex short and double click (autocomplete will finish the polygon).
complete
switch to the edit tool...
edit tool
use the edit tool and the shift to select the polygon you want to merge with.
selection
use the merge command to merge the two.
Merge

  • Man, this is awesome! Thank you so much! I really appreciated that! =D – Matt_Geo Jun 29 '15 at 15:56
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Fastest alternative if you have many holes to cover in a single file is a slight modification of mkennedy's comment suggestion using Union. There is no need to create a second layer that covers the extent of the one you're working with. Simply Union the layer to itself (add only the one layer to the Union tool) and be sure to uncheck the box at the bottom that says Gaps Allowed. The result will be a new layer, with new polygons filling in all the holes. Note this won't work if a 'hole' is along the outside edge - it must be fully enclosed/surrounded by other shapes.

enter image description here

0

Another option, faster than detailed tracing depending on how complex your boundaries are:

Edit the layer and either reshape the feature you want to enlarge to cover the hole using the Reshape Feature tool on the Editor toolbar (left side of image) or draw a whole new feature over the hole (right side of image). In both cases just ensure overlap with neighbors - don't worry about detailed snapping to the existing edges.

enter image description here

Select the now overlapped adjacent polygons one at a time and use the Editor dropdown Clip tool with no buffer and discard area of intersect. This only works on one selected polygon at a time, and be aware it will clip all visible/editable layers. Because it only works on one polygon at a time, if you have many holes or many adjacent polys you can create a temporary copy of your shape layer and merge them all into a single polygon to use for the clipping operation - but this requires use of some extra layers. See my answer at Creating feature class from area in one layer not covered by another layer using ArcGIS? for a detailed outline of this.

enter image description here

In the below image you can see I've clipped using two of the adjacent polys and I have three more to go (using the reshape method from above).

enter image description here

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