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3

This is a classic example revealing the (slight) inconsistency of the spatial predicates compared to the spatial overlay operations (in PostGIS, and the underlying GEOS and JTS geometry libraries). The reason for this is due to numerical precision issues with finite floating-point representation of real numbers. Because the spatial predicates return ...


6

Resolving spatial relationships between adjacent geometries which do not share exactly same vertices tends to be a bit unreliable because of inaccuracy of floating point computing. In this case the first polygon (on the right) does not have a vertex around the top-right corner of the second polygon. The ST_Overlaps and ST_Intersection must create an ...


5

You can use select by expression to select features on the same layer using the expression get_feature. The expression in this case is (see screenshot where the labels show the valule of the Seeding_Ra attribute for each polygon): overlaps( geometry ( get_feature ( @layer, 'Seeding_Ra', 33500 ) ), ...


1

If you have a point layer and a line layer, then you can count the lines near by the points using field calculator: Open the attribute table of point layer Open the field calculator dialog (abacus icon) Enter the following expression aggregate( layer:='line', aggregate:='count', expression:="ATTR",filter:= intersects( buffer(geometry(@parent)...


1

So, your raw data in text format is shown below: P1 MULTIPOLYGON((( 20.0857554080356 49.1905790194619, 20.0887585780746 49.1908207752517, 20.0913701395045 49.1907900830797, 20.0919317359928 49.1903683481409, 20.0914538692795 **49.189904400853**, 20.0901285682587 **49.189850570172**, 20.0894706448357 49.1896357656678, 20.0895286338877 49.1890226017499, ...


3

I can't say how to correct the topology automatically but these images should show what happens. These are the vertices of the left side polygon (clipped1) and the location of the overlap. These are the vertices of the right side polygon (clipped2) and the location of the overlap. The overlap is in the middle of the segment of the right side polygon. The ...


3

The methods mentioned by @Michael Stimson work very well. I tried both ArcGIS and QGIS. The "feature to polygon" in ArcGIS and "Polygon self-intersection" in QGIS do the same thing. They "return a new layer with sub-divided polygons (while only one of the duplicated overlapping area is retained)". The only difference is that in ...


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