Need to display data by zip code inside county boundaries. Help Please!

[MaryMiller1]

Hi,
I have been working with GIS for a few months. I need help with a map request for my boss. I need to display data by county in a state map, However the data was given to me by zip codes. When I display the data for zip codes sometimes overlap county boundaries. How can I display the data for that county by zip code without overlapping the boundaries. Also, how can I just dissolve the zip code inside the county.
Please, I will really appreciate all the help anyone can give me.
Thank you very much,
Mary

[ValerieCribbs]

Hi, Can you give us a few more details on your data and what you would like to achieve? What is the main feature in the map that you're trying to display? The zip codes themselves or some other info that happens to be arranged by zip code? Why is it a problem that the zip code boundaries cross the county lines if this reflects the reality of the situation? Or are you creating each county map separately and wish to hide all data outside the county line? Thanks.

[MaryMiller1]

Hi,
I have to create a state map by county with counts given by zip code. Not all the zip codes are in the list. I also have to break 3 counties down to inset boxes with zip level detail. I have to color grade the counts. I have created a map with zip level detail for the whole state and I don't know how to just display or dissolve the count for each county so it does not display each zip code area for the whole county and only the color of the count per county.

[ValerieCribbs]

I'm sorry but can you explain in detail what you mean by "counts"? (As in "with counts given by zip code".)

[ValerieCribbs · Accepted solution]

Hi Mary,

I spoke to another team member here and she suggested that you try using the Identity tool. If you make the input feature the zipcode layer and the identity feature the county layer you will end up with a combination county/zipcode layer that has the zipcodes split along the county lines.

I hope this helps.

[MaryMiller1]

Thank you so very much!!!

[LareinaLa_Flair]

Good afternoon,

I have the opposite problem -- dissolving the county boundaries between zip codes -- and came across this post while searching for a solution.  Background: I created a study area of zip code polygons using a union between county shape files.  I'd like to dissolve the county boundaries in my study area such that zip codes that cross county boundaries are not duplicated when I aggregate counts of [my feature of interest] per zip code polygon.  For example, if zip code 12345 is split between two adjacent counties A and B, I currently would have two counts of [feature of interest], one for the portion that lies in county A and another for the portion of 12345 that lies in county B.  Does anyone have any guidance for how to dissolve the county boundaries?  Many thanks!