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kind of solved: it appears I need QGIS for this task.

Joining attributes by the biggest overlapping areas in QGIS

• Largest overlap—The feature in the join features will be matched with the target feature with the largest overlap.

It appears I want the opposite: The feature in the Target Features will be matched with the Join Feature with the largest overlap.

Situation explanation

I've a Target-Features layer with many small polygons. And a Join Feature layer with larger polygon features. I would like to join the Name from the larger 'join features layer', to each smaller polygon in the Target Feature, but only the Name from the Join Features layer with the largest overlap with the Target Feature. What could happen is that a smaller polygon from the Target Feature layer, overlaps a bit with two polygons from the Join Feature layer. Then I want the name of the polygon feature with the largest overlap in the Join Features layer.

problem

Now I get only one join from the Join Features to the largest small polygon in the Target Feature layer probably because that one has the 'largest overlap'.

partly solution

In Fields, there is an option to Concatenate the name(s) of overlapping polygons from the Join Feature layer to one Target Feature.

It is not sure whether the overlap is 99% or 1%, but at least there is something.

Edit Field map: Concatenate

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An alternative approach that gives you control over what you select is to use the Union tool with a little bit of post processing, this can be easily wrapped up in a model which I show below.

Test data below are polygons from the joining layer labelled polygon A and B. You can clearly see that polygon B fully overlaps target polygon #1.

Sample data

Model is:

Model

The output of the model is a table which you could pass though a summary statistics again to further filter for maximum value by id and name.

Output table

You could use this table in a relate or join it to the target layer.

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