Buffer (Analysis)

Creates buffer polygons to a specified distance around the Input Features. An optional dissolve can be performed to remove overlapping buffers.

Learn more about how Buffer works


Buffer illustration

Usage tips


Buffer_analysis (in_features, out_feature_class, buffer_distance_or_field, line_side, line_end_type, dissolve_option, dissolve_field)
Parameter Explanation Datatype
Input Features (Required)

The feature layer or feature class to be buffered.

Feature Layer
Output Feature Class (Required)

The feature class that will be created and to which the resulting features will be written.

Feature Class
Distance [value or field] (Required)

The distance used to create buffer zones around Input Features. Either a value or a numeric field can be used to provide buffer distances.

If a negative buffer distance is specified, the buffer offsets will be generated inside, instead of outside, of the input features. This is only valid for polygon feature classes.

If the distance units are not specified, or entered as 'Unknown', the units of the Input Features are used (or if the Output Coordinate System environment has been set, its units will be used).

Linear unit | Field
Side Type (Optional)

Options to buffer to one side of a line or outside polygons

  • FULL—A buffer will be generated on both sides of the line. If the input is a polygon the result will include the area inside the polygon. This is the default.
  • LEFT—the buffer will be generated on the LEFT side of the line.
  • RIGHT—the buffer will be generated on the RIGHT side of the line.
  • OUTSIDE_ONLY—the area inside of the input polygon features will excluded from the resulting buffer.

These options are not available with an ArcView or ArcEditor license.

End Type (Optional)

For lines, the shape of the buffer at the line end points.

  • ROUND—End will be in the shape of a half circle. This is the default.

  • FLAT—Creates rectangular line endings with the middle of the short side of the rectangle coincident with the end point of the line.

These options are not available with an ArcView or ArcEditor license. Line buffers will always have ROUND ends.

Dissolve Type (Optional)

Specifies whether a dissolve will be performed to remove buffer feature overlap.

  • NONE—Individual buffer for each feature is maintained, regardless of overlap. This is the default.
  • ALL—Dissolves all the buffers together into a single feature and removes any overlap.
  • LIST—Dissolves by a given list of fields.

Dissolve Field(s) (Optional)

List of field(s) for the dissolve. Buffer polygons that share the same set of values in their Dissolve Field(s) will be dissolved together.

The Add Field button, which is used only in ModelBuilder, allows you to add expected field(s) so you can complete the dialog and continue to build your model.

Data types for geoprocessing tool parameters

Script Example

import arcgisscripting
gp = arcgisscripting.create()
gp.workspace = "c:/basedata"
gp.toolbox = "analysis"

# Buffer roads.shp based on each road feature's value in the Distance field,
#  and dissolve buffers into groups according to values from Road_Type field.
gp.buffer("roads.shp", "buffered_roads.shp", "Distance", "FULL", "ROUND", "LIST", "Road_Type")

See Also

  • Buffer (Coverage)
  • Dissolve (Coverage)
  • Eliminate (Data Management)
  • Eliminate (Coverage)