Tag: spatial data

What is this place? Des Plaines “park” edition

Screenshot shows the “park” in Des Plaines, Illinois.

I was methodically reviewing features on OpenStreetMap that could benefit from additional attributes, namely missing names and cities. The information on OpenStreetMap feeds into Chicago Cityscape so that the real estate information service I created can show people looking up addresses the locations of nearby amenities, including parks.

This particularly large park in Des Plaines had no name and no city, so I started investigating. From the overhead imagery view, it looked to me like a landfill.

Since there was a forest preserve to the east, I looked in the Forest Preserve District of Cook County’s nice interactive map for any properties near Beck Lake. Nothing found.

Overhead imagery of the so-called “park”. Source: Mapbox

I looked on Google Maps Street View for some insight and there was no name. (Note that data from Google Maps cannot be used to amend OpenStreetMap because of Google Maps having a data license that isn’t compatible with OSM’s openness requirements).

Next I looked at the Cook County parcel map that Chicago Cityscape has to identify its “Property Index Number” (PIN). All of it fits within 04-31-300-003-0000 – the database pointed to “Catholic Cemeteries” as the property owner.

I looked up that PIN on the Cook County Recorder of Deeds to try and find more information. Lo and behold, the most recent document that was recorded against the PIN was for a “Memorandum of Option Agreement” that identified the Catholic Bishop of Chicago as the landlord and Patriot Acres, LLC, as the tenant.

Patriot Acres has a website that describes a new commercial composting facility being built at this location.

I re-tagged the feature on OSM with “amenity=waste_disposal” and “waste=organic” to properly describe it as a composting facility, and not a park. Case closed.

Converting shapefiles and KML files

Google Earth Pro is a slightly more advanced version than the free edition of the popular satellite imagery application (okay, it does way more, but many people just use that feature). One major additional feature it includes is the ability to import GIS shapefiles and display their features on top of the imagery, including terrain. It’s useful to have your data as KML (Keyhole Markup Language) because KML (or KMZ) is easier to share and Google Earth standard edition is free. But then again, it’s useful to have your KML files as shapefiles because proper GIS software is more powerful at analyzing data. Also, someone might ask you for your data in shapefile format (but they could easily follow these instructions).

Good data management requires options. Options mean your data won’t be locked into a proprietary format. Data want to be free! Read on for ways to convert your KML and shapefile data:

Converting KML files to shapefiles

Like Google Earth Pro, Quantum GIS (QGIS) can convert KML or KMZ to shapefile, and best of all – it doesn’t cost $400 per year (it’s free!). QGIS is a cross-platform application meaning it will run on Windows, Mac OS X, and Linux.

Use QGIS to convert a KML or KMZ file to shapefile:

  1. Click on Layer > Add Vector Layer
  2. Find your KML or KMZ file.
  3. Right-click your new layer and click “Save as shapefile.”

Zonums provides online conversion tools. Or, use ArcGIS and this plugin to convert KML files to shapefiles.

Converting shapefiles to KML files

The freeware Shp2kml 2.o (Windows only) from Zonums will convert shapefiles to KML files. Want some free, interesting data to try it out? Check my ever expanding repository.

ESRI’s ArcGIS can convert KML files to shapefiles using this plugin and then import the shapefile as a layer onto your map.

Creating KML files online

As I described in this post, BatchGecode will generate a KML file for you by inputting a list of addresses and names. Additionally, Google Earth (part of the rising Google GIS platform) creates KML files. Google’s My Maps feature also allows you to generate KML files (for sharing or download) by clicking and drawing points and lines on a map and inviting you to describe the features you create. Use this to get a map of your church congregation, or a map of people who voted for your candidate.

GeoCommons Finder lets you upload geodata in many formats, save it to your profile, and then download it into multiple formats. You can upload a shapefile (.shp) and its accompany files (shx, dbf, and prj), verify that it read your data correctly,

More choices for converting

Additional software with conversion capabilities:

  • MapWindow (another free software choice; Windows only) – An alternative to QuantumGIS and ArcGIS.
  • ExpertGPS (Windows only, not free) – Ideal for GPS device owners, or for researchers using GPS devices in projects. But it can convert the GPS and shapefile data into KML, shapefiles, or a spreadsheet, amongst other functions.
  • Zonums, creator of the standalone Shp2kml software converter, now offers many online tools for KML users, including one that reverses the conversion and exports shapefiles from KML files. I found the link on FreeGeographyTools.com.
  • OpenGeo Suite – Commercial software with non-profit licenses.
  • uDig – Free GIS software, but I haven’t had good experiences with it on my computers.

GeoCommunity has a good article, with screenshots, on how some of these programs work.

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