topic Re: Polygon to raster conversion - how to sum values of overlapping polygons in ArcGIS Pro Questions

Polygon to raster conversion - how to sum values of overlapping polygons

LizanneRoxburgh — Mon, 11 Dec 2023 10:39:13 GMT

I have a shapefile with a few hundred overlapping polygons (these are minimum bounding polygons that were fitted around species distribution points). Each polygon has a value. I need to end up with a raster in which each raster cell has a value that is the summed value of the polygons that overlap with that cell. Can anyone advise on the workflow I could use in ArcGIS pro to achieve this? Polygon to Raster does not seem to allow summing the values of the overlapping polygons.

Re: Polygon to raster conversion - how to sum values of overlapping polygons

Remi_Foicik — Mon, 11 Dec 2023 11:08:52 GMT

Hello Lizianne,

I don't know if I understood correctly but you can try the following workflow.

Create a Polygon Feature class like a Grid (each polygon would be a cell in your raster).

Use "the summarize within" tool where you can apply SUM on the fields in you shapefile.
https://pro.arcgis.com/en/pro-app/latest/tool-reference/analysis/summarize-within.htm

Then you can translate you feature class "grid" to a raster with "the feature to raster" tool.

It may not be the most beautiful solution, but it can work 🙂

Another solution : you can transform each polygon into a raster and then apply a raster calculation with all your raster.

Rémi

Re: Polygon to raster conversion - how to sum values of overlapping polygons

DanPatterson — Mon, 11 Dec 2023 11:13:12 GMT

An elegant solution which works is provided here

Counting and rasterizing polygon overlaps in ArcGIS Desktop? - Geographic Information Systems Stack Exchange

which entails union, dissolve and convert to raster

That will give you the counts within each overlapping area.

otherwise,

Split by attribute to get individual layers from the polygon input

Convert to raster

reclass nodata to 0

add the rasters together (Plus tool or just + )

paying attention to cell size, alignment and snap raster

Re: Polygon to raster conversion - how to sum values of overlapping polygons

LizanneRoxburgh — Mon, 11 Dec 2023 12:49:33 GMT

Thanks Remi, that worked perfectly, as we had already set up a grid polygon for processing other layers, so this was the quickest solution.