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I am editing a map using QGIS. Here my steps

1. Select multiple polygons

Select multiple polygons for merging

2. Merge them into one new polygon

Merged polygon with some line in middle

Question: How can I remove those line (in blue circle) and one polygon fully cover the area without any lines or space in between? (this case it only a line but there could be chance that I want to fill some space in between)

Sinh Nguyen
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  • A "quick and dirty" method is to simply use the node tool to select those unwanted vertices (draw a box around them) and then delete them. – John May 10 '22 at 20:17

3 Answers3

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There are different possibilities for manually removing a hole. Easiest is probably solution 1:

  1. Use the Delete ring icon and click on the gap to make it disappear:

enter image description here

Other possibilities:

  1. Draw another polygon that covers the hole and merge again.

  2. Activate vertex tool, mark and delete all vertices of the hole.

Babel
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2

Still another option is the use the tool Delete holes: Menu Processing > Toolbox > Delete holes

Babel
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1

To automatically remove all interior rings, use QGIS expressions with the function exterior_ring() that returns just the exterior ring (boundary), than convert this to a polygon. Like this, all interior rings are automatically deleted. Use this expression to get polygons without holes:

make_polygon (exterior_ring ($geometry))

Use this with either Geometry Generator (visualization only) or Geometry by Expression (for actual geometries). See here for more details about both options.

Initial polygon with hole (yellow) and polygon created with the expression, covering the hole (red lines): enter image description here

Babel
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