topic Re: Problems creating realistic polygons for soil management zones using arcGIS 10.2 raster to polygon in Data Management Questions

Problems creating realistic polygons for soil management zones using arcGIS 10.2 raster to polygon

AndrewWindham — Fri, 29 May 2015 21:34:41 GMT

I am using ArcGIS 10.2 in order to create soil management zones for farmers. The above image represents realistic looking management zones however when I use the raster to polygon tool it create small triangles and very unrealistic looking zones. See image below. I have used the smooth polygon tool, as well as the nibble, focal statistics and majority filter while the files is still a raster in order to reduce the number of zones. Any ideas on an effective way to do this?

Thanks

Re: Problems creating realistic polygons for soil management zones using arcGIS 10.2 raster to polygon

IanMurray — Fri, 29 May 2015 21:56:42 GMT

Have you tried not simplifying the polygons when converting from raster to polygon(No_Similify)? You would have a more complex geometry, but as long as you are viewing at the same scale as the raster, it should look near identical to your existing raster. Once you zoomed it would look more jagged of course, but at a farther out scale, it would work.

You said your original raster looked like realistic management zones, so that might work for you. If you wanted more organic looking polygons at a zoomed in level, you could use the smooth polygon tool or smooth in the advanced editor toolbar

Re: Problems creating realistic polygons for soil management zones using arcGIS 10.2 raster to polygon

FilipKrál — Fri, 29 May 2015 21:57:57 GMT

Interesting, I wouldn't expect this to happen either.

Looks like you used Geostatistical Analyst to get the surface in your first image. Outputs of Geostatistical Analyst tools are not a rasters as such, but geostatistical layers. For further processing with Spatial Analyst tools it is better to export this layer to an actual raster. Then you can use whatever tools you need (although which tools to use a question in itself) and possibly Reclassify and eventually run Raster to Polygon with simplify="NO_SIMPLIFY". This should produce polygons with boundaries following cell edges exactly. Then you can Smooth Polygon or Simplify Polygon for better cartographic representation.

Forgive me if you have done all that and your results are as you posted.

Hope this helps,

Filip.

Re: Problems creating realistic polygons for soil management zones using arcGIS 10.2 raster to polygon

DanPatterson_Retired — Mon, 01 Jun 2015 19:38:30 GMT

Your cell size may be coarse relative to what you want...have you tried to resample to a finer grid size prior to conversion and applying other suggestions