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I want to delete all the internal roads which exists in Block2. These roads don't have any attribute data. It is a single polygon. I need to extract only external roads. Block 2 should be made as Block 1. Block 1 is done by removing internal roads manually using "Cut polygon" tool.

I have so many block to work on. So, wanted to find an easier method

closed as unclear what you're asking by gisnside, ahmadhanb, ArMoraer, mgri, Vince Oct 25 '17 at 10:32

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  • First, thanks for your concern. I want to delete all the internal roads which exists in Block2. These roads don't have any attribute data. It is a single polygon. I need to extract only external roads. Block 2 should be made as Block 1. I have so many block to work on. So, wanted to find an easy method. Please help. – Anu Oct 25 '17 at 9:13
  • Are the external roads Always wider than the internal like in your screenshot? – BERA Oct 25 '17 at 9:23
  • No, some of the internal road's width match with external road's width but don't exceed. But, mostly external roads are wider. – Anu Oct 25 '17 at 9:29
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I would say it is very difficult since they are all the same polygon so you cant identify them by some attribute. If the external roads are wider you could try:

  1. Feature Vertices To Points (Advanced license required):

Creates a feature class containing points generated from specified vertices or locations of the input features

  1. Generate Near Table with the Points as input and with the Location parameter checked:

Calculates distances and other proximity information between features in one or more feature class or layer

  1. From the Near Table select rows/Point pairs with a specified small distance between them, for example all below a distance of just wider than the internal roads and then execute XY To Line:

Creates a new feature class containing geodetic line features constructed based on the values in a start x-coordinate field, start y-coordinate field, end x-coordinate field, and end y-coordinate field of a table.

You should now have created something like the red lines:

enter image description here

  1. Split Polygons With Lines on roads with the lines created:

This modelbuilder tool allows you to split polygons with lines in a geoprocessing operation

  1. Select and delete polygons below a certain area. If external roads get deleted you could try deleting small polygons and not to very elongated (ratio of shape area and shape lenght)
  • I will come back once I get succeeded with your process. Thank you in advance.:) – Anu Oct 25 '17 at 9:38
  • I have got stuck at the 1st step. There are many unnecessary points/vertices generated on a single road. As these may create problem for the next step, I'm trying to remove them by using Simplify polygon tool. But, cannot remove all. I've been trying to add a screenshot in the comment section, but could not do so. Could you also suggest me how to add an image? – Anu Oct 25 '17 at 9:58
  • Then doing it like this might not be possible. – BERA Oct 25 '17 at 10:36
  • Generate Near Table with the Points as input and with the Location parameter checked: What would be the input for "Near features", -polygon? – Anu Oct 25 '17 at 11:09
  • The Points from feature vertices as Points as both in_features and near_features ("The same feature class or layer may be used as both input and near features.") – BERA Oct 25 '17 at 11:11

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