topic Buffer distance inconsistency in ArcGIS Pro Questions

Buffer distance inconsistency

YesimSungu-Eryilmaz — Mon, 02 Sep 2024 00:56:54 GMT

Hello,

I am using ArcGIS version 3.3 and have encountered an issue. I created a 0.5-mile buffer around a point, but when I use the "Measure Distance" tool to check the distance, it shows 0.68 miles. My layer is projected in State Plane NAD1983 FIPS 2001. Could you please advise on how to resolve this discrepancy? Any assistance would be greatly appreciated.

Best,

Yesim

Re: Buffer distance inconsistency

DanPatterson — Mon, 02 Sep 2024 01:28:17 GMT

open a new map, without any basemap

add the buffer layer and only that layer to the map

the map coordinate system should match your featureclass

add the point featureclass to the map and measure the distance now

do you still get the 0.68 mi buffer?

if so, buffer the point again within that map and report what you get

measure the buffer

Re: Buffer distance inconsistency

ChristopherCounsell — Mon, 02 Sep 2024 07:52:08 GMT

When running the buffer tool it will respect the output coordinate system and any transformations.

https://pro.arcgis.com/en/pro-app/latest/tool-reference/analysis/buffer.htm#GUID-E3EA0491-1E80-418B-A884-626F979DC934

This means that the buffer may run and generate in the desired coordinate system (0.5 miles).

But the map may be measuring in the map coordinate system e.g. WGS84 web mercator would throw a different measurement.

As Dan Patterson hinted at, adding the layer to a new map will default to the layer's coordinate system and show the measurements in that.

But one other thing to consider is that you can do planar or geodesic buffers. By default the planar method will be used. Double check what mode is being used in your map when using the measure tool.

https://pro.arcgis.com/en/pro-app/latest/help/mapping/navigation/measure.htm#ESRI_SECTION1_AA3FBCB332934D84993C6EE58ACB6BBC

Re: Buffer distance inconsistency

YesimSungu-Eryilmaz — Mon, 02 Sep 2024 13:56:20 GMT

I changed the map's coordinate system to State plane as it was set to WGS84 and that solved the problem.

Re: Buffer distance inconsistency

YesimSungu-Eryilmaz — Mon, 02 Sep 2024 13:57:09 GMT

Thank you! I changed the map's coordinate system to State plane as it was set to WGS84 and that solved the problem.