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NAME

v.rmarea - Toolset for cleaning topology of vector map.

KEYWORDS

vector, topology, geometry, snapping

SYNOPSIS

v.rmarea
v.rmarea --help
v.rmarea [-bn] input=name [layer=string] [cats=range] [where=sql_query] columns=name[,name,...] output=name [error=name] threshold=float [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-b
Do not build topology for the output vector
-n
Only remove areas along boundaries of reference areas
At least one neighboring area must have selected attributes different from the current area
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog

Parameters:

input=name [required]
Name of input vector map
Or data source for direct OGR access
layer=string
Layer number or name
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Default: 1
cats=range
Category values
Example: 1,3,7-9,13
where=sql_query
WHERE conditions of SQL statement without 'where' keyword
Example: income < 1000 and population >= 10000
columns=name[,name,...] [required]
Name of attribute column(s)
output=name [required]
Name for output vector map
error=name
Name of output map where errors are written
threshold=float [required]
Minimum area size in square meters

Table of contents

DESCRIPTION

v.rmarea removes small areas similar to v.clean. The main difference is that small areas are merged with a neighboring area with identical attributes in the specified columns. An error map is optionally written which stores the erroneous geometries.

Remove small areas

tool=rmarea

The rmarea tool attempts to remove areas <= thresh. The longest boundary with an adjacent area with identical attributes is removed. If there is no adjacent area with identical attributes, the area is left unchanged, even if it is smaller than thresh.

Threshold must always be in square meters, also for latitude-longitude projects or projects with units other than meters.

NOTES

The user does not have to run v.build on the output vector, unless the -b flag was used. The -b flag affects only the output vector - topology is always built for error vector.

EXAMPLES

Remove areas smaller than 10 m2

v.rmarea input=testmap output=cleanmap threshold=10 columns=label

SEE ALSO

v.clean, v.info, v.build, g.gui.vdigit, v.edit, v.fill.holes, v.generalize

AUTHORS

David Gerdes, U.S. Army Construction Engineering Research Laboratory
Radim Blazek, ITC-irst, Trento, Italy
Martin Landa, FBK-irst (formerly ITC-irst), Trento, Italy
Markus Metz, mundialis

SOURCE CODE

Available at: v.rmarea source code (history)

Accessed: Monday Jul 27 12:30:48 2026

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© 2003-2026 GRASS Development Team, GRASS 8.5.1dev Reference Manual