topic Re: Remove not suitable area from polygon in ArcGIS Pro Questions

Remove not suitable area from polygon

Lorenz — Fri, 06 May 2022 11:22:14 GMT

Hey all,

I'm trying to remove not suitable areas from my polygon. To be more specific, I'm trying to identify (and erase) areas ("islands") <23ha, because they are not suitable (too small) for wind energy systems. The goal is to have an overall area on which wind energy systems can be employed.

The image illustrates my problem; e.g., the small 'islands' are not suitable and should therefore be removed. However, it would not make sense to clip them manually, as there are just too many. Therefore: How can I identify these areas and have them removed from my polygon?

Thanks so much for your answers!

Re: Remove not suitable area from polygon

TomGeo — Fri, 06 May 2022 12:20:16 GMT

I take it your polygon is a multipart geometry... In the geoprocessing tools you find 'Multipart To Singlepart', did you try that to separate the multipart input features into singlepart features?

You can then filter the singlepart features by their area and delete those you find not to fit your demands.

If your question is only about on how to filter and delete features based on their attributes... The 'Select By Attributes' tool is your friend to specify your terms, then you simply delete the selection.

Re: Remove not suitable area from polygon

ArchTim — Fri, 06 May 2022 13:30:11 GMT

Alternatively you could select by attributes and export the feature class. That way you don't have to delete the attributes all together and you would still have them for alternate analysis.

Re: Remove not suitable area from polygon

Lorenz — Fri, 06 May 2022 14:28:39 GMT

For which attributes would I filter? It's not really clear to me, how I could select the areas <23ha via Select by Attributes, I've already tried but it did not really work out. Thanks again for your help.

Re: Remove not suitable area from polygon

Lorenz — Fri, 06 May 2022 14:36:05 GMT

Thanks for your help! Just one more question: What would 23ha (230000 square meters) be in the Attribute Table? I don't really get the comma value.

Re: Remove not suitable area from polygon

RhettZufelt — Fri, 06 May 2022 16:10:07 GMT

The Shape_Area field is reporting square map units.

You should be able to use the Calculate Geometry Attributes GP tool to add a new field and calculate area as Hectares. Then you just select where Hectares < 23 and delete. Or, do the math on how many square map units are in 23 ha, then select, etc.

Re: Remove not suitable area from polygon

TomGeo — Fri, 06 May 2022 20:36:46 GMT

The geometry attributes calculation tool can be started by right-click on the attribute tables column header…