Following my previous post I have been digging around archive.org for interesting spatial/ geographical related resources. A search for “geographic” yielded a number of back issues of the National Geographic Magazine. They date back as far as 1888 and contain some great images and maps. There are some real gems to be had, such as the “Scenes from every land” series (link to one here) that contain century-old photographs from every continent. I was also amused to see an article titled “Notes about ants and their resemblance to man“. I have shared a few of my highlights here.
The top map is taken from the 1907 edition of “Scenes from Every Land”. It shows a map of the world with its key trade routes. I suspect today’s equivalent would be much more complex such is the nature of contemporary global transport.
My final two favourites are taken from the 1894 edition of the National Geographic Magazine and illustrate climatic variables for the USA. The top shows the mean temperature for the hottest 6 weeks of the year, and the lower map shows the sum of daily mean temperatures above 6 degrees. Despite their age I really like the clarity and detail in these maps.
Following a slightly critical post about the map featured on ESRI’s Geomedicine website I thought I would balance things with a post on a good example (in my opinion) of a mapping service from ESRI. I was really impressed with their Free Embeddable Maps website. Users can select from a number of demographic measures such as population density, median age, average household size and population change between 2000 and 2009 and map them at a range of scales. Maps can be personalised using a title and direct links to the creator’s website or their email address. My map of New York Median Household Income is here. It would be good to get more data and coverage beyond North America. It would also be nice to enable multiple overlays (perhaps using different forms of representation on the map). The page is only beta so these additions may follow.
I know this kind of thing has been done before, such as with the London Profiler Website, but ESRI’s contribution is remarkably simple to use. Users with no GIS experience will be able to create a map in under a minute. It can then be embedded in a any web page or linked to via bit.ly. The interface is well-thought out and users can read additional information from the pop-outs that appear when the map when they click on an area of interest. The maps deserve to be utilised by a range of users, but I expect educators and their students stand to benefit most from this excellent free service.
As a proud ESRI Developer Centre we were disappointed to see the map on the front page of ESRI‘s recently promoted (via twitter) Geomedicine website. The front page (screen shot below) shows an interactive map of the USA. On it users can overlay heart attack rates (per 100,000 of population) and alongside data showing the locations of reported incidents from the Environmental Protection Agency’s Toxic Release Inventory. Both imply a clear east/ west split across the US with the east fairing worse in both cases. An instant and perfectly reasonable reaction to this visualisation is that heart attacks are caused by the release of toxic material. I felt encouraged to make this assumption by the questions above the map: “What environmental exposures have you personally experienced in your lifetime?” and “Would any of this geographically rich information be useful at your next physician visit?”. Of course, medically, the natural conclusion from the map is spurious, so why have ESRI published it? Scroll to the bottom of the page to the disclaimer which states that no causal link between the datasets is implied and that their intention is “present some of the data about geography as it relates to human health”. By the time you make it that far down the page and squint a little it is too late. I think ESRI could have put a little more thought into this. At the very least they could have shown more data sets, being careful to avoid those that appear to correlate. Changing the “small print” at the bottom to larger more prominent text would also improve people’s perceptions of this map.
Ben Fry has produced a map of the USA’s landscape patterns by plotting only its roads. His All Streets project involved collating network data covering all the roads in the lower 48 United States (26 million road segments!) and mapping them (see below). It is a very simple idea that produces remarkable results. Roads are good representations of population density and the economic value of an area; they also try to follow a line of least resistance. Roads tend to avoid going across the grain of the landscape so you find them concentrating along valleys rather than up the side of mountains. This is clear on the West Coast of America, for example. The resulting image looks like it could have been taken from a satellite and works especially well due to the size of the USA and the quantity of its roads.
Although nowhere near as effective, I have attempted to do the same for Great Britain (see below) using data from Open Street Map. From this you can see the Scottish Highlands, the Lake District in England and the Snowdonia National Park in Wales. My favourite aspects of this map are along the coast where roads tend to follow the edge of estuaries and along rivers inland. Both maps show that landscape features still play an important role in the way we can move around. This perhaps is less surprising in the USA, but serves as a reminder that a small crowded island like Britain still has isolated communities.
Thanks to Allen Pope for sending me a New Scientist article on this.
