21 January 2008

Virtual Geographic Environments

This post links together several ideas linked to virtual geographic environments (VGE), mainly having to do with motivations for creating them.  Notice the word "creating" can refer to the initial setup of a VGE. like Google Earth, and also to creating "posts" or uploads of data by unrelated parties: in the case of Google Earth, this includes posting of photographs of spots by visitors.

Click for larger image

CAPTION FROM GOODCHILD (2007): "A Google Earth mash­up of the area of Soho, London. The contemporary imagery base has been obscured by an 1843 map from the David Rumsey collection.  Superimposed on this are the deaths (green) from cholera in the outbreak of 1854, and the water sources."
Google Earth is actually a replica of an existing landscape that can be used for navigation or sharing of information. "Second Life" is an imaginary landscape, analogous to maps of Middle Earth found in copies of The Lord of the Rings. Much of this post will be referring to a paper by Prof. Michael F. Goodchild,  "Citizens as Sensors: the World of Volunteered Geography" (PDF).1 Goodchild excludes VGEs that do not correspond to literal geographies, although in the future this may be hard to do.

Nevertheless, the events of 1507 [viz., the naming of two continents "America"] provide an early echo of a remarkable phenomenon that has become evident in recent months: the widespread engagement of large numbers of  private citizens, often with little in the way of formal qualifications, in the creation of  geographic information, a function that for centuries has been reserved to official agencies. They are largely untrained and their actions are almost always voluntary, and the results may or may not be accurate. But collectively, they represent a dramatic innovation that will certainly have profound impacts on geographic information systems (GIS) and more generally on the discipline of geography and its relationship to the general public. I term this volunteered geographic information (VGI), a special case of the more general Web phenomenon of user generated content.[...]
The thing that's extraordinary here is actually the flow of data contributed; voluntary and amateur research has been used by geographers all along.2  But that consisted of thematically-specialized data; now we're talking about factual information about a gigantic number of points on the map, such as business reviews that are embedded in a digital map (allowing you to find relevant services).

Maps such as OpenStreetMap are wiki equivalents of Google Earth. Having used both, I've noticed that OpenStreetMap has a different mix of information that makes it useful for, e.g., people investigating real estate development in a selected area.

Digital maps allow the creation of "mash-ups" that incorporate a wide range of data from different sources. Goodchild mentions a map of an 1852 London Cholera Epidemic (p.6; links added):
For example, Figure 5 shows a Google Earth mash­up of the Soho area of London during the 1854 cholera outbreak made famous by Dr John Snow (Johnson, 2006). It combines a street map of London from 1843 (from the online private collection of David Rumsey, a San Francisco map collector) with online data on the water sources and cholera deaths from my own Web site. Readily available software makes this kind of mash­up remarkably easy (see, for example, Brown, 2006)
The advantages of this for epidemiological research or geology seem pretty obvious. Another application is planning by businesses or households planning vacations.  Emergency relief--whether by NGOs or by governments--will be another big beneficiary.

Likewise, smartphones can be equipped with GPS so they can assign coordinates to photos.  VGEs like Flickr Map can plot these on a map, allowing visitors to see photos of an area they want to visit (is it snowy on Mountain Loop Highway this time of year?).

While these developments are encouraging, they face a situation similar to journalism-cum-blogging:
It is easy to believe that the world is well mapped. Most countries have national mapping agencies that produce and update cartographic representations of their surfaces, and remote­sensing satellites provide regularly updated images. But in reality world mapping has been in decline for several decades (Estes and Mooneyhan, 1994). The U.S. Geological Survey no longer attempts to update its maps on a regular basis, and many developing countries no longer sustain national mapping enterprises. The decline of mapping has many causes (Goodchild, Fu, and Rich, 2007). Governments are no longer willing to pay the increasing costs of mapping, and often look to map users as sources of income. Remote sensing has replaced mapping for many purposes, but satellites are unable to sense many of the phenomena traditionally represented on maps, including the names of places
So it remains to be seen if "citizen mapping" can fill a role unavailable to "citizen journalists," who cannot take the place of actual journalists with actual bureax and actual budgets.

This is more than an arch observation by someone often skeptical of the big projected windfalls from intimate electronics. Digital mapping includes a lot of new forms of data that need to be current and documented in order to be useful.
In the mid 1990s the U.S. Federal Geographic Data Committee published its Content Standards for Digital Geospatial Metadata, a format for the description of geographic data sets. The project was very timely, given the rapid increase in the availability of  geographic information via the Internet that occurred at that time. Metadata were seen as the key to effective processes of search, evaluation, and use of geographic information.  Nevertheless, and despite numerous efforts and inducements, it remains very difficult to persuade those responsible for creating geographic data sets to provide adequate documentation. Even such a popular service as Google Earth has no way of informing its users of the quality of its various data layers, and it is virtually impossible to determine the date when any part of its image base was obtained.
Goodchild is struck by the question of motivation--why would people fill in the gaps on sites like Flickr and Wikimapia?  I have to admit, as someone who blogs intermittently, to being puzzled by my own motivations.

  1. Prof. Michael F. Goodchild, National Center for Geographic Information and Analysis and Department of Geography,University of California, Santa Barbara.
  2. See John McPhee, Annals of the Former World, Farrar, Straus and Giroux; 1st edition (2000); see in particular the chapter, "In Suspect Terrain." This book, alas, is exceptionally difficult to find anything in: McPhee includes a "narrative table of contents," which is basically a very large haystack to find a needle in.  


"Volunteered Geographic Information (VGI)," Digital Urban blog (14 Jan 2008); based on Michael F. Goodchild, "Citizens as Sensors: the World of Volunteered Geography" (PDF), Workshop on Volunteered Geographic Information, UC Santa Barbara (December 2007).


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