19 January 14

The New OpenStreetMapper

I didn’t expect I’d launch into 2014 with a whole new hobby. Towards the end of winter break, I bought an 7” Android tablet, the Google Nexus 7. I was not entirely sure what I would do with it, but since it has a GPS chip, it didn’t take long for me to start exploring mapping applications for it. This led inevitably to OpenStreetMap.

OpenStreetMap is a project that has been around almost 10 years; essentially it is the equivalent of WIkipedia for worldwide street mapping. In other words, it is a massive crowdsourcing project to build a quite detailed map database for the world that’s freely available as open data. (There’s an excellent recent blog post entitled simply Why the world needs OpenStreetMap.) I’ve known about the project for a long time (in fact its founder once gave a talk about it to our lab group), but had never signed up to contribute data. Buying the tablet closed a loop for me, since I could now go on walks, pull out my tablet, and check a recent copy of the map to see if there were unmapped details I should record.

Putah Creek trails What does one map? Anything and everything. Looking at the map, I quickly found that neither the California Raptor Center nor the network of trails on the other side of the creek from our house were in there, so I set about mapping them. And now these features are in OpenStreetMap! The figure show the trails I’ve added; they’re the tracks marked in dashed red lines just north of the creek.

It’s amazing amounts of fun. It helps that I’m a map geek already, but walking, exploring, and maps, what could be better?

Posted by at 08:54 PM in Maps | Link | Comment [1]

14 October 10


Tuesday we went to see the movie Gerrymandering, a documentary about the practice of redrawing legislative districts for political advantage. Admittedly the factor that got us to the showing was that Pica’s cousin Susan did the sound production on the movie, but the topic is a good problem in geography. The film focused on the passage of Proposition 11 two years ago in California, an voter initiative to transfer the power of redrawing districts from the legislators themselves to an independent commission. This proposition narrowly passed, and in the finest manner of the carnival that is California initiative politics, there are dueling propositions on the upcoming November ballot to repeal it (Proposition 27) or expand its powers (Proposition 20). The movie was tautly edited, with many animated sketches of the cartographic absurd districts all over the country produced by gerrymandering.

That legislative districts should be at least somewhat cartographically compact is a principle acknowledged by the courts, though rarely seen in practice. I wonder though if there are any sort of “natural” boundaries that can be used to constrain how one draws legislative districts, the problem being that there are an infinite number of ways one can draw lines on a map. After pondering this for a bit I came up with counties, the one set of political boundaries below the scale of individual states that is fairly stable over the years. Of course county boundaries rarely align with population density, and to ensure equal representation some counties would have to be lumped into multicounty districts. By contrast, highly populated counties (for instance Los Angeles County in California) would not be geographically split into separate districts; rather voters would elect several representatives at once from this “superdistrict”. The film interviewed legal scholar Lani Gunier, who it turns out has had ideas along these lines, but the film didn’t go into such alternative ideas. Maybe they fell in interview bits that were left on the cutting room floor.

Posted by at 10:42 PM in Politics | Link | Comment [1]

23 October 09

Roadkill On The Information Superhighway

No, this is not a reference to watching one’s unbacked-up data vanish forever off into the ether…

Rather, it’s to highlight a citizen science website some colleagues of mine have put together. This is the California Roadkill Observation System which allows you to enter observations of road-killed animals in California so that we can better understand what factors contribute to roadkill and then try to reduce these.

I tested out the system this morning and logged a poor jackrabbit that had been hit on the road I take to work. It’s straightforward to use, and has a helpful Google Maps interface for inputting the location.

Posted by at 11:25 PM in Nature and Place | Link | Comment [1]

7 August 09

Unidimensionality, a Reflection

Map of pica's personae Davis is a small enough town that you run into people you know well often, people you know less well just as often, and people you hardly know at all pretty much just as often too (these are the people whose name you have learned several times but can’t remember it, nor can you remember the context in which you last saw them, such memory lapses leading to annual embarrassment which I am now happy to blame on menopause).

One of the middle type (a cyclist) only ever seems to see me as a birder. On running into each other, the conversation tends to go like this:

Me: Hi, D.
D: Hi, A! Guess what I saw at my house yesterday! A heron!
Me: Oh, that’s nice.
D: Yes, it was posing/eating/standing/flying (etc.)

I’m not sure why this bothers me so much, but I think it’s because it reduces me to a tiny fragment of my personality, reflecting only one of scores of interests. (It’s akin to when people catch a tiny fragment of my accent and wonder where in Ireland I’m from.) I have actually raised this with D, that I do a bit more than bird. Readers of this blog probably suspect, with good reason, I’m multidimensional to a manic fault.

So I figured it must be a context thing, and started a map of my different personae across Davis. It’s all in the mapping. What would your personal map look like?

(I realize I have trespassed on Numenius’ turf; it’s both his turn to blog and his profession. Sorry, Numenius. You can have the next two.)

Posted by at 01:48 PM in Maps | Link | Comment [6]

21 June 08

Davis Open Mapping Party

Yesterday I got an email announcement about a Davis OpenStreetMap mapping party to be held today. The OpenStreetMap project is one of these collaborative open data projects that I’ve known about for some time, but haven’t really dived into it, so I was glad to have the introduction to it today. The impetus behind this project is that there is very little street map data in this world that is free in the sense of being legally unencumbered, allowing one to make full creative use of it. The online mapping services provided by Google Maps and Mapquest are good examples of not free-as-in-speech data, but so is map data from most government mapping agencies, e.g. the Ordnance Survey. (The United States is an exception here, since federally-produced mapping data is in the public domain.)

Since everybody and their dog now has a GPS unit, some enterprising geeks came up with the idea to start mapping the world’s streets with their GPSs and make all the collected map data freely available for any use. Thus was born the OpenStreetMap project, which has really taken off in the almost four years it has been underway. As of June 2008 there are over 22 million kilometers of highways and byways mapped in the system, and over 32,000 registered users who are able to add to and update the map, which is essentially a cartographic wiki.

For some reason the project’s founder, Steve Coast, was in town today so a few of us gathered together at the cafĂ© Delta of Venus at 10 AM to plan our mapping session. Thanks to the public domain TIGER data provided by the U.S. Census Bureau, there is good street mapping for most places in the United States, including Davis, already uploaded into the OpenStreetMap, but there are always details to fill in — no maps are ever finished. We decided to work on bike paths and other paths. I opted to head up to the North Davis Greenbelt and collect GPS tracks for every bit of the bike paths there, including the connectors to all the side streets. There is already some mapping of these bike paths in the OpenStreetMap, but there are definitely bits to add.

It was a very hot day today (up to 102° F) and I was glad to return to Delta of Venus for lunch at 1:30 PM. There I got some exposure to the map editing tools but have yet to download the track data off my GPS, let alone start the process of editing the map online.

It’s a great project. There are lots of technical details to learn, much of which are of substantial cartographic interest (e.g. how do you classify the features you’re trying to map), and all completely fascinating from a geographer’s point of view.

Posted by at 11:48 PM in Maps | Link | Comment [2]

4 February 08

Two Historical Atlases

I haven’t seen either of these publications in print, but both are intriguing. First, the U.S. Census has just released their first major atlas is over 80 years. The book has over 800 maps and weighs in at 7 pounds. Happily, the complete content of the book is available as PDF downloads, though each chapter makes for a large download, averaging around 15 Mb apiece.

Second, last fall the University of California Press published a Historical Atlas of California, written by Derek Hayes. With nearly 500 historical maps and illustrations, the book should be a visual feast.

Posted by at 10:30 PM in Maps | Link | Comment

24 August 07

Need A Blank Map?

If you’ve ever felt the need to color in what states you’ve visited, or draw in the route of your upcoming South Pacific cruise, National Geographic offers a series of blank maps for printing and copying as part of their Xpeditions educational resource site.

Posted by at 10:45 PM in Maps | Link | Comment

30 May 07

Google May Be Spying On Your Cat

Their new street-level mapping view is clearly a threat to felinity, as this poor tabby discovered.

(From Boing Boing.)

Posted by at 01:22 PM in Cats | Link | Comment

21 May 07

States I've Visited

create your own personalized map of the USA or check out ourCalifornia travel guide

Oklahoma doesn’t really count but we did drive over the line into the northwest panhandle from Kansas last month and started keeping note of the birds we saw there, so if I technically have a (small) Oklahoma bird list (it contains two species of grackle, burrrowing owl, horned lark, and starling), I’ve been there.

The gaps look strange. Indiana was missed because my mother and I went north in Michigan for the Kirtland’s warbler while we were driving across the country in 1996 and took the ferry to Wisconsin in the pouring rain with a bunch of Mennonites who looked bemused at the karaoke spectacle. Utah? that’s a different kind of trip, and will be undertaken when we’re ready for serious immersion in genealogical records…

Thanks to Steve Rubio for this link.

Posted by at 09:01 PM in Maps | Link | Comment [2]

27 April 07

Which Side Of The Road?

A third of the world’s population drives on the left, according to this definitive reference. A map and list of countries is here.

Posted by at 09:50 PM in Miscellaneous | Link | Comment