1

I need to somehow "join" information from two shape files:

  1. zoning - these are large polygons indicating the zoning code for a moderately large area, typically hundreds of separately owned parcels (see #2) are fully contained in each. The boundary files of zoning seem pretty "rough hand drawn", with boundaries typically running down the MIDDLE of the streets. They are however completely closed and do not overlap.

  2. parcels - these are relatively small polygons, with precise lot boundaries, one for each separately owned parcel. None of these polygons extend out into the street. Related to each parcel id is a lot of useful tabular data, however.... that data doesn't include the actual zoning code (eg residential, commercial, industrial, office/residential, etc, etc, etc.) Ideally I'd like to just "compute" or "look that up" from the more aggregate zoning shapefiles and add a column to the parcels tabular data (unless of course there is a better way...)

Totally new to vector->geo processing tools->

Gave Union a quick whirl but got odd results, long processing time, and a very large output file, perhaps due to the fact the darn zone file borders run down the center of the street vs. the strict property boundaries contained in the parcels file.

4

Assuming the screenshot of my interpretation of your data is correct - you could try the following: interpretation
1) Select menu Vector>Data Management Tools>Join attribute values by location: Join attributes values by location - target-parcels, join-zones

Result: - New poly dataset same as parcels but with additional field(s) from zones. Labels here include both id fields from parcels and zones. result

  • Very good illustrations, works great! Thank you. At first I was confused because when zoomed out its easy to select multiple parcels with a single click (even with Snapping Options off). I thought the join had mangled individual parcels and somehow bound them together. Also, its easy to select parcels and later forget to close ALL the Feature Attribute windows. Even when you uncheck visibility of of each layer in the layers panel the red outlines persist. I thought I had errors in screen re drawing. Not at all, just didn't understand how QGIS worked. Thanks again. – rjlabs Mar 14 '16 at 2:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.