neighboring polygons to a group including 2nd, 3th etc generations

[John]

Hi,

I'm looking for a solution to assign all neighboring polygons to a group. all polygons in a group should have the same number, including neighbors 2nd, 3rd etc. generations. Because there are hundreds of cells (polygons) and groups, manual assignment by assigning a value or editing is not an option. Unfortunately, with the nearest neighbor tool, I can only see the first-order neighbors and no groups.

Does anyone have a solution to my problem? 🙂

Polygon 2084 and 26073 should have the same number because they are connected and so they form a group. 26067, 26070, 26066,26068,... form another group....

[DavidPike · Accepted solution]

You could use the 'dissolve' tool Dissolve (Data Management)—ArcGIS Pro | Documentation to dissolve on a shared boundary, i.e. features that share a boundary are merged into a single feature.

Then perform a spatial join Spatial Join (Analysis)—ArcGIS Pro | Documentation to join the ObjectID field of the dissolved features to all coincident original features.

This would create a new copy of the original features, but with an additional ObjectID field showing which 'group' each feature belongs to.

[DanPatterson]

How Polygon Neighbors Works—ArcGIS Pro | Documentation provides a certain perspective if you are looking for subgrouping contiguity.  The visual examples in the link may help if you have the appropriate attributes in your table

[John]

Thanks a lot for your solutions! 

I have one more question: Is it possible to dissolve on a shared edge additionally to a shared boundary?

[DavidPike]

Hi John,

I'm not sure what the difference is between a shared edge and a shared boundary if I'm honest.  Bit rusty on topology.

[John]

Sorry, of course an edge can also be a boundary.  What I meant, if you look at the picture the polygons with a shared boundary on a complete side are dissolved (this group for example got the number 1063) but I also need the polygon 1066 included. 

[DavidPike]

Ah OK I think you man sharing a 'node'.  If you look at @DanPatterson 's reply you can probbaly identify these with with that tool and 'Node Neighbour'.