topic Re: Seeking to select all polygons capable of containing a circle of a certain dia in Geoprocessing Questions

Seeking to select all polygons capable of containing a circle of a certain dia

DodyAdkins-Perry — Wed, 16 Mar 2011 16:10:58 GMT

Hi,
My boss the town planner is trying to select all parcels of land in our town capable of containing a circle 1,004 feet in diameter. Is there any way of doing this, on ArcView 10 desktop?
Many thanks,
Dody

Re: Seeking to select all polygons capable of containing a circle of a certain dia

JimW1 — Thu, 17 Mar 2011 14:15:44 GMT

Dody,

I got asked this same question by a planner a couple of years ago while working in Urban Planning for SWM ponds or CSO tanks or something stormwater related.

I never really made a full solution to this but what I did do was first query the parcels greater than the area of the circle and make a subset. Then I added a centroid to each of these parcels - irregular shapes got the 'inside' centroid. I then buffered the centriods by 250m (my criteria). I then used the Select by Location tool for all circle features completely in the parcel subset.

Although this was not a complete set of available parcels, it returned something like 80% of the true number based on my visual inspection. I then selected the undeveloped parcels made a pretty map for the planners.

In my case the question really being asked was "Are there any parcels?" not "How many parcels?" but I am fluent in planner (especially senior planner). The planners were happy with the results.

I did the same approach with another set of planners for placing a Municipal Bus Depot and they were also happy.

Hope that gives you a start and it is all doable at an ArcView level.

Re: Seeking to select all polygons capable of containing a circle of a certain dia

DanLee — Wed, 23 Mar 2011 20:08:48 GMT

The following steps may work for you:

1. Select polygons larger than the circle size.
2. Run Buffer tool with a negative value - the value should be the radius of your circle. This will create buffers inside polygons. If a polygon is too narrow, no buffer can be created. If a buffer is created inside a polygon, it means that the polygon has enough room to contain a circle of the radius.
3. Run Spatial Join tool with CONTAINES as the match_option. This should give you all of the polygons in the selection that contain the buffer polygons.

Does this help? Thanks.

Re: Seeking to select all polygons capable of containing a circle of a certain dia

BruceHarold — Fri, 25 Mar 2011 13:42:53 GMT

Hi

Please also see this tool:

http://resources.arcgis.com/gallery/file/geoprocessing/details?entryID=E51354B2-1422-2418-A0F6-8E4F8975BDAD

The comment re. the tool getting some circles wrong appears to be a bug in the Buffer function, this is still being investigated.

Regards