Today is a day to celebrate folks, because today is GIS Day.  As a GIS (geographic information systems) specialist, this day undoubtedly excites me more than it does most people.  But, it is my hope that through my new monthly blog series, Visual Insight, you all will come to love and appreciate this day too.

Some of you may be wondering what GIS is.  I could go on for days about the intricacies of GIS but for now let’s say GIS is a system that lets users analyze and display spatial data (which is a fancy term for information associated with a specific place).  What’s great about GIS is that it is a powerful tool for both analysis and visualization.  Because the information being analyzed in GIS is always associated with a specific location, the critical visualization output you get is a map.

At PAI, I use GIS to identify population and climate change “hotspots” and to create visualizations for our reports, briefs and user guides.

In honor of GIS Day, let’s see just how powerful maps can be.  A DC nonprofit organization called A Wider Circle has a program called “Neighbor-to-Neighbor.”  This program allows area residents to donate furniture and household items to their neighbors living without these basic elements.  According to the data, A Wider Circle’s Neighbor-to-Neighbor program delivered 21,893 items to 2,723 households in 2010.  What do these numbers tell us?  Well, on the surface, the story is a straightforward one: A Wider Circle helped supply 2,723 households in need with basic items for their homes.  But, what can we learn if those households and their donors are put on a map?


Click anywhere on the above image to explore the interactive map.


The map just put those 2,723 households in context and showed us a story we would have never uncovered from numbers alone.  When shown visually, we gain insight about the underlying population A Wider Circle serves and interacts with.  You can see the clear, discernible difference in the geographic locations of donors versus recipients.  We geographers call this a “spatial pattern.”  Happy GIS Day!