Fun with GIS 328: Digital Map Superpowers
One of the most impressive powers of a map is to astonish people. So many times, I have seen people look at a map, eyes focused immediately on the place they call home, and then darting left-right, up-down. They may be struggling with a high volume of data or coming to grips with the degree of differences between places. Dramatic symbols intensify the impact, and people study the map, mentally matching what they see with their lived experiences, and working to envision conditions elsewhere. Maps illuminate patterns, whether about tectonic activity, household income, precipitation, or population density. Use maps in the company of others often enough and you'll see the wide-eyed focus of someone gobsmacked by what they see. "Wow, look at this … we are …" and words trail off as they study more closely.
The Center for Disease Control and Prevention (CDC) has released a powerful map-based online application called the Environmental Justice Index (EJI) Explorer. It presents an index built around environmental, social, and health burdens. Indexes give an "apples-to-apples comparison" over a large landscape, here by integrating different factors to show where challenges pile up, compounding trouble. An Esri blog about this helps readers grasp the challenges and consider how the tool can help citizens and policy makers go beyond just details, grasp the big picture, and focus on changing systems.
Clicking on a location brings up a bank of data about a Census tract. I looked at the map, zooming in and out, comparing here and there. I examined closely the deeply colored places in many areas I know, contrasting them with lighter ones.
But I was frustrated because the landmarks I knew were hidden by the opaque layer. The data layer is downloadable, so I might be able to make my own map, but I wondered if the data might already be visible on ArcGIS Online. Yes, a user had already done this for one area of my interest, and shared it. In Map Viewer, without logging in, I created my own map, zoomed in, raised the transparency, searched for an address, and clicked on the Census Tract. Wanting the background info about data quality, sources, age, and value, I visited the CDC EJI page once more and found the data dictionary (from their download page). Now I could explore my questions, my way.
So, beyond the power to astonish, what's a superpower of digital maps? Customization … it compounds the learning when one can modify the design or even build the maps. It is important to see what experts assemble, to understand the messages they want to transmit. But it also powerful to create one's own version, immersing in the data, seeing the patterns and relationships, banking knowledge while designing a personal experience. Customizing is a superpower!