[GIS] Grouping corner-touching contiguous polygons using ArcGIS Desktop

arcgis-10.0arcgis-desktopdissolvepolygon

Using ArcGIS 10, I have a Feature Class which I converted from a Raster (GRID) (Raster To Polygon Tool).

  • There are approx. 180,000 polygons.
  • The attribute table contains a [grid_code] field which I need to preserve.
  • If one or more polygons are contiguous with corners touching AND they have the same [grid_code] value, then I'd like to group them (a dissolve basically) into one polygon (record).
  • Then I need to calculate the grouped polygon's area.

Using the Select By Location Tool, I'm able to successfully select the polygons that I need to group, but how do I then convert them into ONE polygon, while preserving the [grid_code] ?

Best Answer

You can dissolve contiguous polygons with common id values by using the Dissolve Tool.

  1. Select your Grid code field as your "Dissolve_Field (optional)"
  2. At the bottom of the tool form, check the "Unsplit lines (optional)" checkbox.
  3. Create area field
  4. Right click area field and select Calculate Geometry
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