Puerto Ricans, as U.S. citizens, are able to travel freely between Puerto Rico and the U.S. mainland. In the wake of Hurricane Maria, many of them sought refuge in Florida, New York and other parts of the U.S. Using anonymized cell phone location data for some 500,000 smart phones, data analysis firm Teralytics was able to map where Puerto Ricans moved from August 2017 to February 2018. CityLab has the maps and the story: “Between these months, nearly 6 percent of the Puerto Rican population left the island and is still living in the continental U.S. Another 6 percent left between October and September 2017 but returned to the island by February 2018.”
John Nelson’s map of tornado migration in the United States, showing the seasonal variations in tornado occurrence, is a master class in data visualization and design—in deciding on the right way to present geographic information. The map combines three styles—impressionistic choropleth, weighted mean centre movement diagram, and small multiple—to present month-by-month information all at once; in the accompanying text (also here), Nelson discusses some of the alternatives he could have chosen instead. And in a separate post he talks about how he made the map. [Esri]
As promised, Kenneth Field has uploaded the final web version of the quick-and-dirty dasymetric dot density map of the 2016 U.S. presidential election results, which he posted to Twitter last month. Unlike the quick-and-dirty version, the final version is in high resolution and can be zoomed in to quite a preposterous degree. One dot, one vote. [Kenneth Field]
In February the FCC released a new broadband map showing the availability of high-speed internet in the United States. The previous map was apparently useless, but the new map has been coming in for its share of criticism as well because it doesn’t match the reality on the ground. Partly it’s because the map shows the number of internet providers providing service by census block whereas actual availability is more granular than that. But only partly. Techdirt’s Karl Bode says both old and new versions of the map “all-but hallucinate available options out of whole cloth while vastly over-stating the speeds available to American consumers”:
For example, I can only get access to one ISP (Comcast) at my residence in Seattle, purportedly one of the nation’s technology leaders. Yet the FCC’s new map informs me I have seven broadband options available to me. Two of these options, CenturyLink DSL and CenturyLink fiber are somehow counted twice despite neither actually being available. Three others are satellite broadband service whose high prices, high latency and low caps make them unsuitable as a real broadband option. The seventh is a fixed-wireless option that doesn’t actually serve my address.
Winter isn’t quite done with us yet where I live. And with that in mind, here’s a neat animated map from the Washington Post that shows the total accumulated snowfall in the contiguous United States. The link includes 48-hour snowfall accumulation maps, satellite imagery, and a map showing which areas of the lower 48 have had more or less snowfall than Washington, D.C. I imagine these maps will have to be updated now.
Earlier this week, Kenneth Field posted a quick-and-dirty dasymetric dot density map of the 2016 U.S. presidential election results to Twitter. It quickly went viral. In a subsequent blog post, he goes into some detail about the process of making the map. “The screengrab was quick and dirty and while there have been many and varied comments on the ‘map’ it’s by no means the finished article. I want to create a hi-res version and also make a web map like the 2012 version. I don’t have time to do this in the next couple of weeks but it will happen. But I am aware of a number of issues and some have already spotted them as have many others.”
We’ve seen maps reimagining the United States reorganized into a different number and configuration of states before, but this map by Reddit user Upvoteanthology_ looks north of the border for inspiration. It imagines what would happen if the U.S. were organized like Canada, with the same population imbalances: Ontario, for example, has 38.9 percent of the Canadian population, so this map imagines a superstate, Shanherria, with 38.9 percent of the U.S. population that spans the entire U.S. South, plus Kentucky, Missouri, Kansas and the non-Chicago parts of Illinois. Meanwhile, Maine is roughly equivalent to Prince Edward Island, and the three northern territories map to Alaska.
The maps that appear from time to time on xkcd are usually a lot more whimsical than the one Randall posted today: his somewhat belated “2016 Election Map” assigns one figure for every 250,000 votes for each of the 2016 presidential election candidates. As Randall says in the alt text,1 “I like the idea of cartograms (distorted population maps), but I feel like in practice they often end up being the worst of both worlds—not great for showing geography OR counting people. And on top of that, they have all the problems of a chloro… chorophl… chloropet… map with areas colored in.” This is an issue that election map cartographers regularly have to deal with, as many of my readers know well.
The Urban Institute’s interactive map of debt in America explores the geography of debt, paying particular attention to medical debt and the racial (white vs. nonwhite) breakdown of debt, down to the county level. [Kottke]
The highest and lowest ranked causes are highlighted when the chart loads. These represent the cumulative ranking across all years. Lightning, a natural cause, often floats to the top, but that’s only because on the human side, the vote is split between more than twenty options. Lightning doesn’t predominate in all states, though. In Alabama, the number one cause is pyromania. In Indiana, it’s brakeshoes. In Minnesota, it’s field burning. There are a couple of overall trends, too. Smoking is going down as a cause, and powerlines are going up.
The results of last week’s special Alabama senate election have been crunched and mapped. Matthew Isbell looks at some of the factors that contributed to Doug Jones’s upset win: education, race and voter turnout. Lots of county-by-county choropleth maps to mull over here. Meanwhile, the Washington Post is not the only one to map a salient point: Jones won the state but lost six out of seven congressional districts, thanks to the way those districts were drawn—a function of race, majority-minority districting, and gerrymandering.
The Washington Post assesses Democrat Doug Jones’s chances against Republican Roy Moore in the Alabama Senate election next month by mapping three factors: the extent to which Moore underperformed Mitt Romney in 2012 (Moore ran for chief justice of Alabama in 2012 at the same time Romney ran for president), the racial makeup of Alabama’s precincts and the 2016 precinct-level election results.