ArcMap

MergeDissolve

Available with Production Mapping license.

Summary

Dissolves lines and polygons that touch based on field values.

Discussion

This function can be used to merge smaller features within the same feature class so they are all part of the correct subtype. For instance, suppose you have shrub and grass next to each other. At a larger scale, it may be easier to see the grass symbol beneath other features than the shrub. In this case, you could merge the shrub with the grass so it is easier to see on larger-scale maps.

Syntax

MergeDissolve (input_feature_layer, field, order)
ParameterExplanationData Type
input_feature_layer

The features that are going to be merged.

Layer
field

The field used to merge features. Features are only merged if the field values match.

Field
order

Indicates whether the field values are prioritized in ascending or descending order. For instance, suppose you have two building features—one with a subtype of 0 and a description of Unknown—and another with a subtype of 1 and a description of Education. If you use the subtype field to determine the merging, ascending order would cause the features to be merged as part of an Unknown building feature. Descending order would cause the features to merge as part of an Education feature.

  • ASC —The field values are prioritized in ascending order.
  • DESC —The field values are prioritized in descending order.
String

Code sample

MergeDissolve example

This example merges park features.

import arcpy
import arcpyproduction
from arcpyproduction import generalization

# set environment
arcpy.env.workspace="c:/Data/LocalGovernment.gdb"

# Check out Production Mapping license
arcpy.CheckOutExtension("Foundation")

# Define variables
inFeatures="ReferenceData/FacilitySite"
field='fcode'
where="FCODE='Park'"

# Create a feature layer
inFeatLayer=arcpy.MakeFeatureLayer_management(inFeatures,"Facilitieslyr",where)

# Execute the MergeDissolve function
generalization.MergeDissolve(inFeatLayer,field,'ASC')

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