Dissolve (Coverage)

This tool only works with an ArcInfo license and will only be available in ArcToolbox if you have installed ArcInfo Workstation.

Creates a new coverage by merging adjacent polygons, lines, or regions that have the same value for a specified item.


Dissolve illustration

Usage tips


Dissolve_arc (in_cover, out_cover, dissolve_item, feature_type)
Parameter Explanation Datatype
Input Coverage (Required)

The coverage containing features to be dissolved.

Output Coverage (Required)

The coverage to be created.

Dissolve Item (Required)

The item in the in_cover feature attribute table that is used to dissolve features.

  • Dissolve_item—An item name will be used to perform the dissolve. The item may be a redefined item.
  • #ALL—All items past the Cover-ID in the PAT, AAT, or region subclass PAT will be used as a single dissolve_item. If there are no items past the Cover-ID, then the Cover-ID will be used.

ArcInfo Item
Feature Type (Optional)

The feature classes to be preserved in the out_cover:

  • POLY—Polygons will be dissolved; an AAT will not be created for the out_cover. This is the default option.
  • LINE—Nodes will be dissolved; a PAT will not be created for the out_cover.
  • NET—Polygons will be dissolved, and both a PAT and AAT will be created for the output coverage.
  • REGION.subclass—Region subclass will be dissolved, and all existing attributes of the in_cover will be maintained in the output coverage.

Data types for geoprocessing tool parameters

Script Example

# Dissolve vegetation coverage features into unique regions

# Create the Geoprocessor
import arcgisscripting
gp = arcgisscripting.create()

# Local variables...
workspace = "C:/project93/data/"
vegtype = "vegtype"
veg_holland95 = "veg_holland95"

    # Set the current workspace (to avoid having to specify the full path to the feature classes each time)
    gp.workspace = workspace

    # Process: Dissolve coverage features...
    gp.Dissolve_arc(vegtype, veg_holland95, "HOLLAND95", "region.vegtype")

    # If an error occurred when running the tool, print out the error message.
    print gp.GetMessages()

See Also

  • Dissolve (Data Management)
  • Aggregate Polygons (Coverage)
  • Aggregate Polygons (Data Management)
  • Eliminate (Coverage)