topic Urgent question on data transfer in ArcMap in 911 GIS Questions

Urgent question on data transfer in ArcMap

BrandonBastiaans — Thu, 10 Jan 2019 14:32:44 GMT

I have a neighbourhood shapfile which also has the population/number of citizens per neighbourhood. My question is:

Can I transfer this data on population to a polygon grid? The grid polygon borders ofcourse don't align with the neighbourhood borders, so can ArcMap automatically transfer percentages of the population size to the grid polygons, so that every polygon in the grid will have a population size (assuming that citizens are perfectly dispersed over the neighbourhoods).

Re: Urgent question on data transfer in ArcMap

Anonymous User — Thu, 10 Jan 2019 15:29:32 GMT

Hi Brandon,

It can! Run the neighborhood shapefile through the Make Feature Layer tool with the Use Ratio Policy enabled on the population field (and on any other fields you might want to output in this manner). When Use Ratio Policy is enabled, whenever a feature in an overlay operation is split, the attributes of the resulting features are a ratio of the attribute value of the input feature. The output value is based on the ratio in which the input feature geometry was divided. For example, if the input geometry was divided equally, each new feature's attribute value is assigned one-half of the value of the input feature's attribute value. Use Ratio Policy only applies to numeric field types.

Then run a Spatial Join on the grid with the neighborhoods as the join and whatever statistics you'd like (probably Sum for total population):

This or some version of this should work, I think. Here's some documentation on joins and the Make Feature Layer tool:

Make Feature Layer—Help | ArcGIS Desktop

About joining and relating tables—Help | ArcGIS Desktop

Essentials of joining tables—Help | ArcGIS Desktop

Others may have other suggestions as well, but I hope that helps!

-Lauren

Re: Urgent question on data transfer in ArcMap

deleted-user-qpvAI3Fo0MKR — Thu, 10 Jan 2019 16:30:50 GMT

Every day I learn a new capability of the software. Thank you kindly, Lauren Dreyfuss‌

Re: Urgent question on data transfer in ArcMap

BrandonBastiaans — Fri, 11 Jan 2019 14:44:41 GMT

Hey Lauren,

Thanks for the quick reply! I tried to follow your advice but for some reason the join function won't join all grid polygons: