In this project, I have three polygons, see the image below

  1. "Polygons_From", includes input attributes, i.g. "Value_1", "Value_2", "Value_3", and $area for each quadrate (on the image there are two types of them).
  2. "Polygons_To" polygons for which new values "Value_1_new", "Value_2_new", "Value_3_new" need to be defined
  3. "Border" defines an area where the calculation should be done.


My task is to transfer values from "Polygons_From" into "Polygons_To" based on a certain aspect/ratio. Of course, I can simply achieve it with 'Union' function as was suggested in this thread.

It uses $area-factor, but perhaps there are better approaches that will lead me to a much more efficient output?

So, I am asking for a recommendation regarding the technique/workflow that can be applied in QGIS 2.18. Shall I consider only $area or there are some other criteria?

Moreover, I looking forward to finding some papers that may improve my general understanding of the methodology.



Some "Polygons_To" are in more than one "Polygons_From" so you should decide to:

  • Duplicate polygons in "Polygons_To" to match number of intersections with "Polygons_From" layer. To do this You can use 'Join atributes by location' with one to many option selected.

  • Or use Union tool from 'Vector' menu to split "Polygons_To" that intersect with more than one poylgon in "Polygons_From".

Think its also possible to list atributes of all intersecting layers into one column but havent tried it yet.

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