Alternative to GeoJSON? #76

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1. chris commented on Apr 4, 2022

   

   Chris Bailey (chris)

   on Apr 4, 2022

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   Since you're using an ArcGIS product, maybe a shapefile will import better? If you have the GDAL command line tools, you could convert the GeoJSON file to a Shapefile with something like:

   ogr2ogr -f "ESRI Shapefile" Minnesota.shp Minnesota.geojson
   

   In general, most of these are quite large files, so opening the entire state in QGIS or similar may not be very workable. There are a variety of different ways you can do this, but I'd boil this down to two basic categories:

   1. Load the data into PostGIS and then do queries on it for what you're after. You can also query for the geometries within an area you're studying and then export that back out to GeoJSON.
   2. Write a program that reads in the GeoJSON and filters it similarly to PostGIS mentions above.

   I've also seen some GeoJSON "splitting" utilities out there. I haven't used any, so don't know much about them, but they may be a way to simply break the single state file up into say 10 smaller files.
2. andwoi commented on Apr 4, 2022

   

   andwoi

   on Apr 4, 2022

   Last edited by andwoi

   Contributor

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   I suspect QGIS is crashing because the file is too large. As Chris Bailey (@chris) mentioned, you can split the geojson files into smaller chunks and work with it that way. Here's a python snippet that will look for individual polygon features and write line-delimited geojson (geojsonl) that QGIS can work with. This doesn't require additional modules over python's standard library. Hope that helps!

   import json
   
   # decompressed geojson file. 
   with open("Minnesota.geojson") as inf:
       counter = 0
       batch = 0
       # adjust this value to change the number of features per file.
       buildings_per_file = 500_000
   
       file_template = "Minnesota-{}.geojsonl"
       target_file = open(file_template.format(batch), 'w') 
       line = inf.readline()
       while line:
           # filter to look for polygon features
           if 'Polygon' in line:
               line = line.strip().strip(",")
               parsed_line = json.loads(line)
               geom = parsed_line['geometry']
               target_file.write(f"{json.dumps(geom)}\n")
               counter += 1
           if (counter > 0 ) and ((counter % buildings_per_file) == 0):
               target_file.close()
               print(f"completing batch {batch:,}. total lines extracted: {counter:,}")
               batch += 1
               target_file = open(file_template.format(batch), 'w') 
           line = inf.readline()
       target_file.close()
       print(f"completing batch {batch:,}. total lines converted: {counter:,}")
   

   ❤️React with ❤️1Reacted by Chris Bailey
3. alasdairrae commented on Dec 28, 2022

   

   Alasdair Rae (alasdairrae)

   on Dec 28, 2022

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   If anyone's looking for files that will load into QGIS (or similar software) quickly then I have a set I batch converted to GeoPackage (gpkg) with gdal - here they are: https://automaticknowledge.co.uk/us-building-footprints/

   (note that they are not the very latest iteration of the files)

   This is what I used to batch convert the files didn't take too long do do the whole set, maybe a few hours, and now I can load single states into QGIS much more quickly

   for %f in (*.geojson) do ogr2ogr -f "GPKG" %~nf.gpkg %f
4. alasdairrae commented on Feb 27, 2023

   

   Alasdair Rae (alasdairrae)

   on Feb 27, 2023

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   For anyone looking for files that load into QGIS (or other GIS software) much faster than the original geojson files, then we have produced an updated set of geopackage files for each state, available here:

   https://automaticknowledge.co.uk/resources/#USBuildings

   These were converted to gpkg from geojson and we also added in county codes and names so that users can filter by county if they need to.
5. npr99 commented on Feb 27, 2023

   

   Nathanael Rosenheim (npr99)

   on Feb 27, 2023

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   Thank you!
6. sumanttyagi commented on May 8, 2025

   

   Sumant Tyagi (sumanttyagi)

   on May 8, 2025

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   did any one notice there is some shift and rotation error in many of the footprint when overlaid on WorldImagery ?