This week we’ll broach the topic of datums, coordinate systems, and map projections in the GIS class that I teach at Cornell. It’s week 5+ of the semester, just enough into this stuff so that there’s some sustained knowledge growing and they now have enough of a framework onto which to hang the obvious-but-abstract-and-necessary-but-confusing-and-powerful topic. I used to be more GIS-traditional about this stuff and dive in during weeks 2 or 3. Not any more. Much more and deeper learning taking place now that students are more confident and competent at managing and manipulating spatial data. T
Just in time, XKCD has come up with another inspired projections example to share with the class.
New challenges for the projection-minded. What new types of distortion can be created with these?
The Art of Ornamental Orange Peeling, circa 1905
braids and twists
There’s a hip trend going around, making simple maps with labeled spaces. At least one or two a week have been crossing my computer screen lately. I’ve always referred to this approach as using maps as organizational templates. In most cases the map-makers don’t go into telling a story about why the data are where they are. They’re just labeling a place with its information, and leaving the rest up to us. The map is serving as a way to represent data by virtue of its geographical location. That is, we start with some data, and that data happens to have a 1-to-1 relationship with some location, like a state in the US, or a country in the world.
We could use a spreadsheet as an organizational template instead. In fact, many of these maps started that way. Start with a spreadsheet with an alphabetical list of all 50 states (plus D.C., which often gets overlooked), and then another column in the spreadsheet has some information about each state (let’s call it an “attribute” of that State). And maybe we know different attributes for different years.
Problem: looking at an Excel spreadsheet is boring. And it’s virtually impossible for us to envision a “pattern” from a spreadsheet. States or countries arranged alphabetically tells us nothing about the geospatial relationships among those places. Did I already mention it’s boring. Our eyes glaze over. Who wants to have glazed eyes?
Instead, by labeling each state – or country – or region – with the attribute, we can appreciate the geographic pattern of said information. When the data are categorical or nominal, you might get a map like what the most popular boy’s name has been in each state over the last 60 years, or the girls’ names, or surnames in Europe, how the Russian language engenders the names of world countries, or what each world country is “best at” (which is a wonderfully subjective way to begin a discussion), with the label being a word or a phrase.
Such data can often be represented pictorially or through icons, like the “most famous book” in each State (again, who gets to decide that?!), or the Food of the States. At least they remembered D.C.!
I don’t know, maybe it’s just me. But I’m seeing these maps all over the place these days.
I love it when somebody manages to collect original data of something that we’ve all seen before, with new details and insights. This swipe-enabled image of the geology of El Capitan in Yosemite National Park is terrific.
New to me: the current project being undertaken by “guerrilla cartographers” to create a food atlas. I love the premise, I love the process, and I know I’ll like the product. Go mappers!
Time Magazine reports on a study (pdf) that considers the connections between hazard maps and recent natural disasters. Are “bad maps” to blame for greater-than-expected damage, death, and destruction? Among other issues, the study authors suggest that mapmakers may lack adequate “humility and caution.” Of course that may be true, but it’s so much more complicated than that. Map makers rely on the data they have, not the data they want. They are required to generate maps that rank risk based on models that necessarily have fragmented, incomplete, sampled, and uncertain data. The cartographic symbology necessary to communicate this uncertainty is often lacking.
Which for me gets to the interesting set of questions. Understanding the connections between a map maker, the representation itself, and the decision makers on the other end. Few map makers set out to create a map that leads to poor decisions. What happens along the way? How can we do better to reduce confusion and re-align intentions? How can we improve feedback mechanisms so that the next generation of maps is “better”? Really, no map is inherently “bad” – so we need a better set of terms, and expectations, and practices, so that effective maps help support the best decisions.
Some lovely and gentle hand-drawn maps from Emily Robertson, followed by some woodcut ones via Bob Vila.
Maps of the United States shapes comprised of their bird feathers, by kelzuki on esty, and maps shaping other forms and objects, by Matt Cusick.
Finally, some philosophical thoughts linked to inspirational images, by Maptia.