I am using QGIS for the first time.

I have a map of an aquifer with 2 different vector layers that split the aquifer differently into several polygons. In the first layer, I used some points(measuring stations) to create Voronoi polygons, in the other layer I got the polygons from vectorizing a Raster that has some land attributes, now I want to know how much area of each of the colorized layer fits into each of the Voronoi polygons.

For example, how much green, blue and light green are in each of the Thiessen polygons below?

I need to know for each one, not the total sum, because each Voronoi polygon has some different values that I will have to use later.

Both layers joined with union tool

  • 2
    You probably have assigned an ID to each of your Voronoi-Polygons. If yes, then use the intersect tool, then calculate the $area of your smaller polygons, then either run statistics or copy & paste everything into excel, where you dissolve/sum by the ID.
    – Erik
    Dec 14, 2020 at 15:13
  • 1
    Please edit your question trying to quit the context of hydrology and going to more specific terms of GIS. Is the erik's comment clear? Dec 14, 2020 at 17:39
  • Thanks Erik, it worked out!
    – Andrés RD
    Dec 14, 2020 at 20:50


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