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Question

Area gap and overlap cleaner

  • June 29, 2023
  • 7 replies
  • 57 views

pabloolivaresm
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I am working with a forest geopackage, in which small forest roads, rocky areas and other surfaces are not included in the forest layer. What I am looking to do is to make all these spaces part of the forest area. I tried with Area gap and overlap cleaner but I didn't get results, because the problem is that there are roads that I would like to keep as such or other surfaces that I don't want to be converted to forest. Any idea how to proceed?

7 replies

redgeographics
Celebrity
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How do you identify the roads etc that you want to keep? Is there a rule that you can can build in FME?


daveatsafe
Safer
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  • Safer
  • June 29, 2023

Hi @pabloolivaresm​,

I am attaching an annotated workspace template that uses the TopologyBuilder to create arc/node topology, then tests the resulting edges to determine which can be removed to merge the small polygons into the larger ones. Finally, it rebuilds the polygons from the remaining edges. Please try it out and see if it is useful for your case.Screen Shot 2023-06-29 at 11.32.10 AM


pabloolivaresm
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How do you identify the roads etc that you want to keep? Is there a rule that you can can build in FME?

Hi, I have a landcover layer, so i just made a tester to keep only the four categories of forest that im interested


pabloolivaresm
Supporter
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Hi @pabloolivaresm​,

I am attaching an annotated workspace template that uses the TopologyBuilder to create arc/node topology, then tests the resulting edges to determine which can be removed to merge the small polygons into the larger ones. Finally, it rebuilds the polygons from the remaining edges. Please try it out and see if it is useful for your case.Screen Shot 2023-06-29 at 11.32.10 AM

Hi @daveatsafe​, thank you for your response. I will try but i must confese its a little bit confuse. Also, the layer i have it contain just the forest landcover, maybe will not be possible to try your template


redgeographics
Celebrity
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Hi, I have a landcover layer, so i just made a tester to keep only the four categories of forest that im interested

An alternative transformer you can try is the AreaAmalgamator. Based on what you're telling me I think that that would probably be a better solution.


daveatsafe
Safer
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  • Safer
  • July 4, 2023

Hi @daveatsafe​, thank you for your response. I will try but i must confese its a little bit confuse. Also, the layer i have it contain just the forest landcover, maybe will not be possible to try your template

It should work for the forest landcover. Quite a bit of the complexity is to allow you to designate polygons that you don't want merged (ie. road polygons), but you can also set all the the polygons to dissolvable in the AttributeValueMapper, and it will still work OK.


pabloolivaresm
Supporter
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thanks you all, I found another solution before FME processing. The roads its still a problem but its ok for i wanted.