13 maps in 13 days: Steven Romalewski

Sending off the year 2015, we present to our readers the mapmakers who contributed their work to the 2015 GeoHipster calendar.

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Steven Romalewski

Q: Tell us about yourself.

A: I manage the CUNY Mapping Service, a project of the Center for Urban Research at the Graduate Center of the City University of New York. I’ve been using GIS to analyze and map all sorts of data since the early 1990s.

Q: Tell us the story behind your map (what inspired you to make it, what did you learn while making it, or any other aspects of the map or its creation you would like people to know).

A: We created the map as part of our Election Atlas for the 2013 mayoral election in New York City, a compilation of dozens of maps of demographics, voter registration, vote histories of the mayoral candidates, turnout, and more. This particular map shows voter turnout by election district for the 2013 mayoral primary. It’s a different take on most election maps: each election district is shaded by color according to the candidate who won the district, and the intensity of each color corresponds to turnout percent (rather than vote percent). So it shows how well each candidate mobilized their supporters, as well as areas where candidates won the district with only weak turnout. Citywide turnout for the primary was only 22%, but the map shows how varied the turnout was across the city and by candidate.

We learned a great deal with this map and all the others at the Election Atlas about election district geography, voter registration data, and Board of Elections vote reporting.

Q: Tell us about the tools, data, etc., you used to make the map.

A: All the NYC Election Atlas maps were made with ArcGIS, and then uploaded either as PDFs/PNGs to our Atlas website, and some of them (including this one) are also available in interactive form using CartoDB, where you can click to see turnout and vote totals by district for the mayoral primary and general election. We relied on ColorBrewer for the color patterns (we <3 ColorBrewer!). The vote results and voter registration data are from the NYC Board of Elections. This map and the others were very much a team effort among me, David Burgoon, Kristen Grady, and our colleagues at the Center for Urban Research. And the Election Atlas overall is a partnership with the CUNY Journalism School and Center for Community and Ethnic Media, in order to provide visual and quantitative resources for journalists and others covering the election.