[GIS] Filling holes in polygons automatically using QGIS

polygonqgis

Is there an option in QGIS to fill holes in polygons automatically by setting parameters e.g. maximum area, distance between borderlines?

I want to delete/fill holes that a very "thin"/small.

Best Answer

Using QGIS 2.10.1-Pisa with Processing version 2.10.2, there are a couple of tools available from the Processing Toolbox:

Fill holes tool which you can specify the maximum area.
Delete holes tool which would be applied to the whole input layer.

For QGIS 3.x, the Delete Holes tool combines both of the above functionalities. You can optionally specify a maximum area of hole to delete. If left as 0.0, the tool will delete all holes of any size.

Related Solutions

[GIS] How to delete rings automatically using QGIS/Grass

I am assuming that these small rings are "donut holes", or gaps within the polygon (and am mostly writing this for better search result hits, as the title is a bit ambiguous to me).

My solution to this using GRASS GIS is as follows:

# (optional before starting: clean features
v.clean in=original_import out=original_map tool=bpol,rmdup
v.build map=original_map

# 1. Add centroids to the holes
v.centroids in=original_map out=map_with_centroids
# 2. Drop the current table and and one that includes the 
#    areas that now have centroids and a value column that
#    you will use to dissolve the areas
v.db.droptable map=map_with_centroids -f
v.db.addtable map=map_with_centroids columns='value INT'
# 3. Update this "value" column with the same value everywhere
v.db.update map=map_with_centroids col=value value=1
# 4. Now combine the areas by dissolving them together
v.dissolve in=map_with_centroids out=map_noholes column=value

If you rename "original import" to your input map name and "map_noholes" to your desired output map name, you should be able to just copy/paste this block.

[GIS] Adjusting polygons to boundary and filling holes

Use ST_DumpPoints to get a set of vertices for each polygon in 3.
From that construct Voronoi Polygons around your vertices
Dissolve the Voronois by grouping
Clip the resulting shapes with your department boundary.

Best Answer

Related Solutions

[GIS] How to delete rings automatically using QGIS/Grass

[GIS] Adjusting polygons to boundary and filling holes

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