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I am a beginner in ArcGIS Pro. I asked a question before (Expanding IDW interpolation to borders of country in ArcGIS Pro?), but I feel like I do not understand the basics enough, so a more basic question now.

I have a dataset with concentrations measured at 20 locations in the Netherlands. I want to cover all of the Netherlands with IDW interpolation/extrapolation, using the Geostatistical Wizard.

So not like this, but everything up until the borders:

enter image description here

I understand I have to set Analysis/Environments/Processing extent to the border of the Netherlands.

How can I make a shapefile of the border of the Netherlands so that I can use it to define the processing extent?

I used this, but that doesn't work:

https://learn.arcgis.com/en/projects/cartographic-creations-in-arcgis-pro/lessons/add-and-symbolize-countries.htm

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    The symbology only affects the appearance, it does not create any kind of processing extent. You need to use a shapefile of the Netherlands, It looks like you have one. But as you mentioned that you have been playing with symbology I also suspect you are just using a basemap. Basemaps are just a background image. You need a polygon. If you dont have it, you can download it from this site : diva-gis.org/datadown . Check the projection. Once you have done that, go back to your previous post and use IDW using the shapefile as a mask. Good luck! – Roberto Zeeland Nov 9 '18 at 9:09
  • Thanks for your answer! This works very well when I use the normal IDW tool, but still not in the Geostatistical Wizard. Maybe it is just not possible to define the borders with a shape file while using that application? – Qeshet Nov 20 '18 at 9:00
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I inquired in your question and your previous question. Hence, I couldn't add a anwer there because you marked it as answered. Anyway, you dont create a shapefile, you download a shapefile for further processing. Sources can vary, OSM provides with good data, geofabrik.de too. In order to be helpful for this and your previous question I replicated the situation only to realize that my ArcGIS Pro Geostatistical Wizard was not licensed. But I did it in QGIS and here I have the result. So, my step to step procedure.

  1. Downloaded a shapefile of http://www.diva-gis.org/datadown , selecting the Netherlands (adm boundary 0)
  2. Created a random point file with random values (in your case not necessary)
  3. Imported both files into QGIS
  4. Selected the IDW Interpolation tool
  5. Selected a cell size value of 600 and had a look at here just to make sure I was on the right track.watch
  6. Had a look what the coefficient value was here
  7. Reviewed the options, cell size 600 and extent of the raster adjusted to layer extent. I believe this is a error you would have to correct in your statistical wizard as your raster is bounded by the points at the extremes . Hence, you have no buffer around your points. See below.
  8. Ran the algorithm just to get this image below. test1
  9. Clipped the raster by mask layer, in this case the shapefile with country borders. (Dont overlook the data types, a shapefile is vector based.)
  10. Played with the symbology (transparency 80%, background map) Test2.

I had no time to look for a better bounding shapefile. Notice that in my test case the islands are too narrow and the Ijsselmeer is not land but is marked as land (not useful in case you want to make land surface comparisons) etc.

In case you want a fast solution follow these steps. In case you want to give a go to your ArcGIS solution, try to make the raster size bigger, so it overlaps the whole country. Once you get a result to your liking, extract by mask.

  • Thanks for this very clear explanation. A very late reaction from me... I have tried this and it works very well. I stopped using the Geostatistical Wizard in ArcGIS, because apparently that wizard does not extrapolate. – Qeshet Apr 4 at 7:22
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As you are using ArcGIS Pro one of the improved things is it's ability to draw data from online portals. You don't need to go anywhere to get any data as generic datasets such as country boundaries are all accessible right inside ArcGIS Pro!

Open up the Catalog pane, select Portal, Living Atlas and type "Netherlands", second dataset is a Netherlands Country Boundary for 2017.

Living atlas

  • Thanks for your answer. I tried this, but it did not work in the Geostatistical Wizard. – Qeshet Nov 20 '18 at 8:09
  • Just an idea, once you have found the layer and loaded it into your map, try saving it off to a local file geodatabase? – Hornbydd Nov 20 '18 at 11:16

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