As those of you who frequent the blog know, we're mostly interested in mapping and analyzing user-generated geographic information in the aggregate -- whether it be all the Google Maps references to a particular keyword or the number of geotagged Wikipedia articles within a certain country. From time to time, however, we like to talk about other interesting applications of web 2.0 spatial applications.
Although incredibly simple, one such interesting application for historical research is Google Earth's photo overlay feature. All it takes is an old map or aerial photograph and some free time, and you can begin to click and drag your way into comparing historical imagery with something a bit more up-to-date.
For a couple different reasons, I've been playing around with this feature quite a bit lately, mostly in analyzing urban development in Floatingsheep's North American home base of Lexington, KY. The following image is something I put together for some research my partner Emily has been doing on urban renewal in downtown Lexington.
The map shows a Sanborn Fire Insurance Map from 1909 overlaid on the area around Rupp Arena in downtown Lexington. In the late 1970s, a 16-acre neighborhood full of predominantly poor, black residents was demolished in order to make way for the parking lot that now sits across the street from the Lexington Civic Center and Rupp Arena, where the University of Kentucky plays its basketball games. And while a simple overlay can't tell the full story of urban renewal in Lexington, such a visualization is helpful in understanding just how much was lost in this particular case .
For my master's thesis research, I've used an old development plan for the University of Kentucky's Coldstream Research Campus to visualize just how much the plans for the campus have (not) been realized. Even though an exact date for the development plan isn't available (I've dated it somewhere between 1993-1996), it's possible to see just how little has actually been built at Coldstream in that time .
While these are two pretty basic examples that can't be totally divorced from the larger research projects they are a part of, they show the power of using web 2.0 spatial applications like Google Earth for other projects, especially those that have a historico-geographical element. Got any other good examples? Feel free to share them in the comments!
 It should be noted that the neighborhood likely experienced some degree of change in the intervening 70 years. The point, however, remains.
 Similar to the above note, the current Google Earth imagery for Lexington is incredibly out of date, circa March 2002, and several more buildings have been built at Coldstream since that time. Again, however, this does not refute the point at hand.