Data for Mapping Workshop

This workshop provided a definition and general overview of GIS (Geographic Information Systems), presented by Javier Otero Peña and Olivia Ildefonso, two of the GC’s Digital Fellows with expertise in this area.  Their presentation was very well-organized, and they both provided examples and useful tips along the way.

GIS are tools that enables one to manipulate and represent data spatially on maps.  While these tools can be complex and are very powerful, Javier and Olivia provided an introduction on the way that maps are organized (vector or raster layers).  Vector layers contain data from files which can be in many different formats.  It is these data layers that can enrich a map by providing a spatial representation of the data in visual form (as opposed to reading a table with rows and columns).

I’ve done a few assignments using a GIS tool this past summer– and while those projects were focused on how to use the tool, there was little discussion on how one gets the data (it was already provided in the exercises).  I remember struggling when searching for data to add to my map:  how did I know which database was reliable, what format to use, how to search for the correct fields?  These were the questions I had, and I did my best to muddle through it.

I appreciated that his workshop was focused on how to search for different data sets and load them into the GIS mapping program.  The whole point of using GIS is to marry the data with the map, and I suspect that this critical step is often not touched on in GIS tutorials.

For this session, the intention was to walk the group through a mapping exercise using Carto, an open-source mapping program.  There was an unanticipated change in the software, so we were unable to open accounts and log into Carto.  No matter, as we were able to focus on the main point of the session.

Given that the subject of this workshop was to locate the data and import it into the program, we were able to focus on this (and not be distracted with creating a map at this point).  I thought that both Javier and Olivia did a great job of walking us through each step, and offering tips and strategies for saving files, naming fields, etc.  We searched for the US Census data, chose a table and then narrowed down the fields that we needed and saved the file.  Then we searched for a shapefile for the census tracks; and then “joined” the information from the table with the shapefile (using a common field, in this case ‘state’).

The slides were very clear, and Javier emailed the Powerpoint slides to us afterwards – which now serve as a mini-tutorial for us to replicate on our own.

Javier and Olivia were both knew their stuff and were very effective at tailoring their presentation to the group’s level. I thought that this was just enough for an intro to the topic, and I’m definitely interested in a follow up that delves deeper into finding and evaluating sources of data.