topic Creating multiple non-overlapping buffers in ArcGIS Pro Questions

Creating multiple non-overlapping buffers

GeoQuest4567 — Thu, 17 Apr 2025 19:07:56 GMT

Dear Community,

I am trying to use the Multiple Ring Buffer tool to create a set of non-overlapping buffers (e.g., 100 m, 200 m, 300 m, 400 m) around 50 polygons, which are different sites. I am running into a few challenges:

The non-overlapping option of the dissolve parameters creates multipart buffers, whereas I need them to be singleparts (i.e., each buffer around each site should be a separate polygon). Trying the multipart to singlepart tool does not work because some of these buffers overlap, as some sites are somewhat close to one another.
Whereas the overlapping option of the dissolve parameter returns the attributes of the original polygons (around which buffers are formed), the non-overlapping option does not return the attributes of the original polygon.

To sum up, I am trying to generate a series of non-overlapping buffers (rings) around multiple sites. Then, I need to know which buffer is associated with each site, so I would ideally have an attribute in the buffer shapefile that corresponds to the site id.

I would be grateful for any suggestions on how to achieve this!

Re: Creating multiple non-overlapping buffers

BobBooth1 — Thu, 17 Apr 2025 19:38:06 GMT

Might try using the multi-ring buffer tool in a ModelBuilder model with an Iterator.

https://pro.arcgis.com/en/pro-app/latest/help/analysis/geoprocessing/modelbuilder/iterators-for-looping.htm

Use Inline Variable Substitution so each of the output feature classes (one for each of the sets of buffers) has a unique name.

https://pro.arcgis.com/en/pro-app/latest/help/analysis/geoprocessing/modelbuilder/inline-variable-substitution.htm

Append the feature classes together.

https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/append.htm

Re: Creating multiple non-overlapping buffers

Ed_ — Thu, 17 Apr 2025 19:46:17 GMT

For this part "Then, I need to know which buffer is associated with each site" maybe try: the buffer, since it's a circle, its centroid should be pretty close to the site centroid. So, with those centroids you can do a nearest spatial join to get the site id to know which buffer goes with which site. I am sure there might be a better straight froward way to do this.

For the sites that are completely within its buffer with no other site overlapping that buffer, you may try a completely within spatial join

Re: Creating multiple non-overlapping buffers

DavidPike — Thu, 17 Apr 2025 23:55:46 GMT

I think you have a simple option of a spatial join to the original points with 'Have their Center in'. the Centroid of any buffer ring will have a centroid coincident with the site.

Re: Creating multiple non-overlapping buffers

AlfredBaldenweck — Mon, 21 Apr 2025 16:17:14 GMT

Multiring buffer should include data with the original feature. Unfortunately, as you have found out, that doesn't work if the Donut option is chosen. Here's a relevant Idea: Analysis Tools: Multiple Ring Buffer: Don't dissol... - Esri Community

To Ed's point, it turns out the centroids of each buffer are different, which is super frustrating.

So, here's a toolbox with two tools to fix that.

They turn the disc output of multiring into donuts without sacrificing the attributes.


Before	After

One tool (Punch out buffers) works after you've made the buffers, while Clean Donuts buffers the input feature and gets the nice donut result all in one go.

I've only lightly tested these, so your mileage may vary, but it's worked for me so far.

I'll be sharing this toolbox to that Idea as well.

Re: Creating multiple non-overlapping buffers

DavidPike — Mon, 21 Apr 2025 16:36:22 GMT

I don't understand how or why the Centroids would be different for a donut annulus, even for multipart polygons.

Re: Creating multiple non-overlapping buffers

AlfredBaldenweck — Mon, 21 Apr 2025 17:52:25 GMT

I don't know why either, but here's the proof:

When I was figuring out the code, my initial thought was to go by centroid.

Note that the buffers and the original point are in this coordinate system.

Original point at the bottom, with the other three buffer centroids above.

You also get different stuff if you check arcpy geometry.

So, anyway. They do not have the same centers, which means that if you try to match centroids, you won't get any results.

My solution was to check the ORIG_FID field and work with that. You can check my code to see how I did it.

Full disclosure, I have a hard time with coordinate systems and stuff, so that may be another wrinkle to this, but I tried to keep everything consistent while testing this.

Re: Creating multiple non-overlapping buffers

AlfredBaldenweck — Mon, 21 Apr 2025 17:55:56 GMT

Also, to be fair. That initial test I just showed was buffered geodesic. Buffering planar (again, keeping spatial references consistent) gives a much tighter spread, but a spread regardless.

Re: Creating multiple non-overlapping buffers

DavidPike — Mon, 21 Apr 2025 18:18:25 GMT

I've done the same using a 'normal' coordinate system and all the Centroids are the same as I'd expect. Calculate Geometry Attributes and Spatial Join 'Have their Centre in' work as expected.

I think this may be Aerial distortions from using WMAS coordinate system. I would guess that if you did the same experiment in the Southern Hemisphere that you would see the opposite drift of Centroids.

Or it's some difference in versions causing the default to be 'inside' which seems a bit unwanted to me.

Re: Creating multiple non-overlapping buffers

AlfredBaldenweck — Tue, 22 Apr 2025 14:03:17 GMT

Well, I repeated the experiment and here's what I got:

I ran it twice: once on a point in NAD 1983 (GCS, WKID: 4269), and once on NAD 1983 UTM Zone 13N (PCS, WKID: 26913)

Steps:

Set map to the spatial reference
Create point feature class in matching spatial reference
Create point feature
Calculate its XY in the same spatial reference
Use multiple ring buffer tool on point, once using planar and once using geodesic
Calculate the centroid of each buffer
Compare buffer centroids to point.

Here's what I found:

NAD 1983 (Geographic)
- Calculating the centroid for the geodesic and planar buffers yielded the exact same results.
- That said, they were not the original point
NAD 1983 UTM Zone 13N (Projected)
- The centroids of the planar buffers matched the original point exactly.
  - Well, except for it rounded the X.
- The centroids of the geodesic buffers varied from each other and from the original point.
  - Interestingly enough, they spread out on the X axis this time

Re: Creating multiple non-overlapping buffers

DavidPike — Tue, 22 Apr 2025 20:48:00 GMT

how I understand it is that the the Geodesic buffer in NAD1983 Geographic is not a regular annulus or circle. The circle or annulus will be like a squash ball squished against the poles. This greater area of the buffer above the buffer origin point (for Northern Hemisphere) then forces the Centroid up to account for the changed centre-of-mass. This will increase non linearly as you increase the buffer distance.
I'd use a big (1000km) geodesic buffer and then visualise it in the same geographic projection. I think when you see that it would make sense what's occurring.

For the UTMZ13 coordinate system I may be wrong in this one as this topic is admittedly very confusing - but it seems to me that it's showing the distance distortion away from the central meridian of the transverse mercator projection (105 West?). I would then say your buffer point is West of -105 degrees, and if you recreated the example with a point East of -105 degrees you would see the centroid shift in the opposite direction.

Re: Creating multiple non-overlapping buffers

BobBooth1 — Wed, 23 Apr 2025 20:56:48 GMT

You could set up a model to use the ordinary buffer tool. Buffer the input polygons once. Then buffer the resulting features, and then buffer the next set of resulting features. Then, append two of the result feature classes into the other one.

Seems like it works.