Category: Tools

Free online GIS tools: An introduction to GeoCommons

Read my tutorial on how I created the pedestrian map with GeoCommons. Read on for an introduction to GeoCommons and online GIS tools.

GeoCommons, like Google My Maps and Earth, is part of the “poor man’s GIS package.” It’s another tool that provides (few) of the functions that desktop GIS software offers. But it excels at making simple and somewhat complex maps.

I first used GeoCommons over a year ago. I started using it because it would convert whatever data you uploaded into another format that was probably more useful. I mentioned it in this article about converting files. For example, if you have a KML file, you can upload it and export it as a shapefile for GIS programs, or a CSV file to load into a table editor or spreadsheet application.

After creating the Chicago bike crash maps using Google Fusion Tables, I wanted to try out another map-making web application, one that provided more customization and prettier maps.

I found that web application and created a version of the bike crash maps, with several other data layers, in GeoCommons. I overlaid bike counts and bikeways so you can observe some relationships between each visual dataset. My latest map (screenshot below), created Wednesday, shows pedestrian counts in downtown Chicago overlaid with CTA and downtown Metra stations, as well as the 48 intersections with the most pedestrian collisions (from this UNC study, PDF).

Screenshot of pedestrian count map described above.

How these online GIS tools can be useful to you

I bet there’s a way you can use Google Fusion Tables and GeoCommons for your job or project. They’re extremely simple to use: they can take in data from the spreadsheets you’re already working on and turn them into themed reference maps. With mapping, you can do simple, visual analysis that doesn’t require statistical software or knowledge.

Imagine plotting your client list on a map and grouping them by age to see if perhaps your younger clients tend to live in the same neighborhoods of town, or if they’re more diverse (should you do this, keep the map private, something that you can’t do in GeoCommons – yet).

You may also find it useful if you want to create a route for your salespeople or for visiting church members at their homes. Plot all the addresses on a map, then manually filter them into different groups based on the clusters you see. With Google Fusion Tables, you can easily add a new column with the GROUP information and apply a numbered or lettered group and then re-sort.

Other things you can do in GeoCommons

  • Merge tables with geography – I uploaded two datasets: a table containing census tract IDs and demographic information for Cook County I downloaded from the American FactFinder 2; and a shapefile containing Cook County census tracts boundary information. After merging them, I could download a NEW shapefile that contained both datasets.
  • Make multi-layer maps
  • Symbolize based on frequency/rate
  • Convert data – This is by far the most useful feature. It imports “shapefiles (SHP), comma separated values (CSV), Keyhole Markup Language (KML), and GeoRSS” and exports “Shapefile, CSV, KML, GeoRSS Atom, Spatialite, and JSON” (from the GeoCommons user manual).

Read my tutorial on how I created the pedestrian map with GeoCommons.

How to create a map in GeoCommons

GeoCommons (GC) is like Google My Maps but more powerful. Read my introduction to GC.

Tips before starting

  • With GC, I’m still figuring out what I must decide before I choose to add or amend something and what I can edit after I’ve made a change.
  • You cannot edit the data table directly.
  • You CAN replace data – click “reupload” – but the columns must match between original and replacement data.
  • Click Save often when making the map. You never know when Adobe Flash is going to quit on you.

One of the busiest locations in Chicago, for people walking, or riding buses and trains. Also a lot of taxi traffic and medium bike traffic. At Adams Street and Riverside Plaza (er, the Chicago River).

Tutorial

  1. Prepare your data.”We support Spreadsheets (as CSVs), Shapefiles, KML, RSS, ATOM and GeoRSS. We also support WMS and Tile services!” GeoCommons has instructions on how to prepare your spreadsheets for geocoding (if not already geocoded; GC will also work with predefined XY coordinates or street addresses). Ensure fields holding numbers have their type set as numeric in the GIS or spreadsheet program or you may run into roadblocks later on when trying to analyze these fields.
  2. If uploading a shapefile, GC requires the SHX and DBF files as well. The PRJ file will also help GC know how to reproject your data on the fly. GC base layer maps are projected in WGS84, just like Google Maps. Without the PRJ file, your data may not show. [Can the user set projection?]
  3. Upload data.
  4. You need to turn your newly uploaded data from a “pending dataset” to a completed dataset. In this process you will tell GC a little more about your data, including which columns hold the XY coordinates (even though it guesses this). you can also change the attribute names and describe the content of those attributes (you can also change this later).
  5. So click “Next Step” to start this process.
  6. In the “Review Your Geodata” step, you may see that GC has found some additional columns in your dataset. I’m not sure why this is. Delete these columns by selecting the header and clicking Delete Column. Then click Save Changes. You can select multiple columns at a time by holding the Command (Mac) or Control (Windows) keys.
  7. Add metadata; edit attribute names and add descriptions.
  8. You’re done. GC will present you a page with statistics and options to download your data in different formats.
  9. If you want to make a map with more data, follow the process again starting at Step 1. If not, continue.
  10. Make a map! Click “Map Data” or the “Make a Map” button in toolbar.
  11. A map of the world will load. When GC has finished loading your “new layer,” the map will zoom in.
  12. For the pedestrian map, I want to symbolize the data with a single color but changing the size of the circle based how many people were counted there (your data must have this attribute in numeric form – if it doesn’t you may have to reupload your data). Click “Add Data” and then in the Map Brewer box that appears by:
    1. Click on Visual Theme. Click next.
    2. Select the NUMERIC attribute. In the pedestrian data, this is “count.”
    3. Then select whether or not you want colors or sizes. You can not change this later. You would just delete the layer and add the layer again (using your already uploaded dataset).
    4. Select what type of classification you want. This is entirely up to you and how you want the map to look and based on what data you have. You can change this later.
    5. Choose your shape and color.
  13. Add more data by clicking Add Data button. I think my map would be more useful and interesting if it also showed where the train stations are, a major destination category for people who walk downtown on weekdays. I will symbolize by a solid color. Instead of visual theme, which I chose for the ped counts, I will just choose Points, Lines & Areas. At this time, GC doesn’t allow custom icons.
  14. Re-order layers by dragging them up and down in the layers box. Click on the boxy “handle” to the left of the layer.
  15. Change the layer names by single clicking on the layer name. Press Enter when you’re done.
  16. Change the map name by singe click on it. Press Enter when you’re done.

After creating my pedestrian map, I had some suggestions for GeoCommons, the people who collected the pedestrian count data, and my own map.

  • GeoCommons should add a map preview image for better sharing on Facebook and other websites that look for this.
  • GeoCommons should allow maps to be private after creation – I think after you click save, they are added to a gallery (I could be wrong).
  • The data collectors should add more locations, particularly around Union Station and the two Clinton CTA stations (also between CTA and Metra stations).
  • The data collectors should add “date collected” to the data table
  • The data collectors should extend survey hours to better match commuting patterns. A majority of the collections end at 5:45 PM while Metra’s rush hour ends just before 7 PM (this is when train departure frequency drops).
  • I should add ridership data to the train stations so we can see which CTA and Metra stations are most used.

Bike crash map in the press

Thank you to the Bay Citizen, Gapers Block, and the Chicago Bicycle Advocate (lawyer Brendan Kevenides). They’ve all written about the bike crash map I produced using Google Fusion Tables. And WGN 720 AM interviewed me and aired it in April 2011.

View the map now. The map needs to be updated with injury severity, a field I mistakenly removed before uploading the data.

The Bay Citizen started this by creating their own map of bike crashes for San Francisco, albeit with more information. I had helped some UIC students obtain the data from the Illinois Department of Transportation for their GIS project and have a copy of it myself. I quickly edited it using uDig and threw it up online in an instant map created by Fusion Tables.

A guy rides his bicycle on the “hipster highway” (aka Milwaukee Avenue), the street with the most crashes, but also has the most people biking (in mode share and pure quantity).

Why did I make the map?

I made this project for two reasons: One is to continue practicing my GIS skills and to learn new software and new web applications. The second reason was to put the data out there. There’s a growing trend for governments to open up their databases, and your readers have probably seen DataSF.org’s App Showcase. But in Chicago, we’re not seeing this trend. Instead of data, we get a list of FOIA requests, or instead of searchable City Council meeting minutes, we get PDFs that link to other PDFs that you must first select from drop down boxes. But both of these are improvements from before.

I would love to help anyone else passionate about bicycling in Chicago to find ways to use this data or project to address problems. I think bicycling in Chicago is good for many people, but we can make it better and for more people.

Read the full interview.

Converting Google My Maps to KML and GPX

Convert your routes that you made in Google My Maps to GPX so that you can view them on Garmin GPS devices, or upload them to MapMyRide.

  1. Access your My Map. Your My Map must have lines or routes in it. It appears that a My Map with only points doesn’t convert correctly.
  2. Click on View in Google Earth. Your web browser will download a KML file. It may automatically open in Google Earth, but this is not necessary.
  3. Visit GPS Visualizer to convert your KML file to GPX
  4. Select GPX as your output.
  5. For the input, choose the KML file you just downloaded from Google My Maps.
  6. Click Convert. Your file will be uploaded and your GPX file will be presented for download on the next page.
  7. Download your GPX file from the link on the page.

You can now transfer the GPX file to your GPS device, or upload it to MapMyRide. I confirmed that MapMyRide successfully imports the Google My Map I converted following these instructions.

Trying out uDig, a free, multi-platform GIS application

ArcGIS is the standard in geographic information system applications. I don’t like that it’s expensive, unwieldy to install and update, and its user interface is stymying and slow*. I also use Mac OS X most of the time and ArcGIS is not available for Mac. It doesn’t have to be the standard.

I’ve tried my hand at Cartographica and QGIS. I really like QGIS because there’re many plugins, it’s open source, there’s a diverse community supporting it, and best of all, it’s free. I’ve written about Cartographica once – I’m not a fan right now.

My project

  • The data: Bicycle crashes in the City of Chicago as reported to IDOT for 2007-2009
  • Goal: Publish an interactive map of this data using Google Fusion Tables and its instant mapping feature.
  • Visualizing it: Added streets (prepared beforehand to exclude highways), water features, and city boundary (get that here)
  • Process: Combine bike crash data; reproject to WGS84 for Google; remove extraneous information; add latitude/longitude coordinates; export as CSV; upload to Google Fusion Tables; map it!
  • View the final product

Trying out uDig

In reaching my goal I had a task that I couldn’t figure out how to complete with QGIS: I needed to combine three shapefiles with identical table schemes into one shapefile – this one shapefile would eventually be published as one map. The join feature in fTools wasn’t working so I looked for a new solution, uDig, or “User-friendly Desktop Internet GIS.”

The solution was very easy. Highlight all the records in the attribute table of one shapefile, click Edit>Copy, then select the destination table and click Edit>Paste. The new records were added within a couple seconds. I could then bring this data back into QGIS to finish the process (outlined above under Project). I did use fTools later in the process to add lat/long coordinates to my single shapefile.

After adding more data to better visualize the crashes in Chicago, I noticed that uDig renders maps to look smoother and slightly prettier than QGIS or ArcGIS. See the screenshot below.

A screenshot of the three bicycle crash datasets (2007, 2008, 2009) with the visualization data added.

The end product: three years of police reported bicycle crashes in the City of Chicago on an interactive map powered by Google Fusion Tables, another product in Google’s arsenal of GIS for the poor man. View the final product.

*I haven’t used ArcGIS version 10 yet, which I see and read has an improved user interface; it’s unclear to me and other users if the program’s been updated to take advantage of multi-core processors. ESRI has a roundabout way of describing their support.