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I have to create Thiessen polygons with the spatially weighted averages for specific contaminate concentrations from different borings. I have the Thiessen polygons created but this only shows me the polygons based on the point locations not actually point concentration values that I would like. What tool can I use to get this info?

I only have ArcGIS free trial which limits the amount of tools I have access too. I also have QGIS and could use either to do solve the problem.

Chris W
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rkc1316
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  • You can give the Thiessen polygons the attributes of the points using Feature to Polygon and include the points as centroids... is that what you're after? – Michael Stimson Feb 24 '15 at 22:56
  • I'm only aware of one VB based tool for Arc to do this linked in the answer at http://gis.stackexchange.com/questions/123317/. There is mathematical discussion of the problem at http://gis.stackexchange.com/questions/17282/. Solutions frequently go into raster-based territory. However I stand by my comment in your earlier question that Thiessen/Voronoi is the wrong approach for your data, and you really want to be doing interpolation. Even weighted, the polygon approach doesn't give accurate depiction of the variation in contamination between points. – Chris W Feb 25 '15 at 01:24
  • Euclidean allocation produces a result too (requires spatial analyst). Can you clarify what you're after (a picture would be nice)? Is it that you want the cells to be smaller around less/more weight or do you want to see your contaminant values in the polygons? – Michael Stimson Feb 25 '15 at 03:06
  • I think you should focus your question on one GIS product, otherwise you are effectively asking two questions (one per product) when the [Tour] says there should be only one. – PolyGeo Jul 18 '16 at 05:44

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