topic Re: Polygons in Mapping Questions

Polygons

AquilesSaz — Fri, 28 Aug 2015 20:34:02 GMT

Hello there,

Do you know an easy way to increase the size of a polygon uniformly and maintain its shape? I am using ArcMap 10.2 version.

Re: Polygons

DarrenWiens2 — Fri, 28 Aug 2015 21:24:56 GMT

You can use the top-secret Scale editing tool, which is in the Editor category of tools, although not added to the Editor toolbar by default. Follow the instructions on the Scaling a feature help page to add the button.

Re: Polygons

AquilesSaz — Fri, 28 Aug 2015 22:18:21 GMT

Thank you for this great tip.

Sorry but I did not place the right question, this is my case:

I drawn a polygon following an hydro survey sheet, said polygon ends with 15.0 acres of land. Now I have to adjust the polygon shape from 15.0 acres of land to 14.0 acres of water rights, do you think this is possible in ArcGIS?

Thank you in advance for any help you can provide

Re: Polygons

XanderBakker — Sat, 29 Aug 2015 00:32:23 GMT

Could you visualize what you are trying to obtain? There are possibly many ways that could provide what you are looking for, spatial adjustment, buffer, etc, but a picture would help to understand the specifics of your question.

Re: Polygons

DanPatterson_Retired — Sat, 29 Aug 2015 01:24:50 GMT

as what has been said by Xander and Darren...particular since you imply a spatial shift in the land to water mention. Is the land adjacent to the water ?(not mention, perhaps implied) Does water rights mean surficial water of subsurface water?

Re: Polygons

AquilesSaz — Mon, 31 Aug 2015 14:24:44 GMT

Thank you for your advice. Basically, I am trying to reduce an existing polygon area from 15 acres to 14 acres at the same time I need to keep its shape. See the attached image

Re: Polygons

AquilesSaz — Mon, 31 Aug 2015 14:25:32 GMT

Thank you for your advice. Basically, I am trying to reduce an existing polygon area from 15 acres to 14 acres at the same time I need to keep its shape. See the attached image

Re: Polygons

DanPatterson_Retired — Mon, 31 Aug 2015 15:14:11 GMT

A negative buffer by area should keep the shape the same as one would have to do in the field by producing normals to the original outline and then connecting the points. The trick is to find the offset distance which produces an area reduction of the desired size. This has to be done iteratively since it isn't a regular geometric shape. In fact if the buffer size is large relative to the original shape, you can collapse the polygon in on itself so that the original shape will be unrecognizable. I can't find any references to current tools except this one

http://www.arcgis.com/home/item.html?id=10b2645c4fcd4daf97100720d417424c

but I am not sure if it does negative buffere

Re: Polygons

AquilesSaz — Mon, 31 Aug 2015 19:44:28 GMT

Thank you Dan!