The penultimate EEO-AGI seminar of the academic year, entitled ‘PastPlace: Rethinking Gazetteers for the Semantic Web’ was given by Dr. Humphrey Southall of the University of Portsmouth. His talk focused on the development of PastPlace, a global historical linked gazetteer created as part of the Great Britain Historical GIS research project based in the University of Portsmouth’s Geography department. The creation of PastPlace required what Dr. Southall described as a geo-semantic approach; history is about texts, not maps. Up until the 18th century there were almost no maps, and those which do exist can be difficult to interpret and digitise today. Furthermore, historical textual descriptions are often more accurate than other attempts to describe geography at the time. Itineraries and gazetteers are the main sources of information containing placenames.
Dr. Southall noted that a historical gazetteer differs to modern gazetteers in that they require references to places from various sources and time periods to be linked to one place, they must allow for uncertainties in geographical knowledge of the past and, in addition to the location of a place, should tell the user what places were like. However, as it was not possible to build PastPlace from scratch, it was necessary to use an existing modern gazetteer to form its core. A number of gazetteers were considered for this purpose. Ultimately, it was decided that Wikidata, a major geographical resource which integrates Wikipedia articles in different languages, would form the basis of the historical gazetteer. Pelagios 3 also forms the basis of PastPlace. This is a two year project which aims to annotate, link and index place references in digitised early geospatial documents, such as geographic descriptions and world maps, which originate prior to the European discovery of the Americas in 1492. The Portsmouth team aim to augment PastPlace with contemporary and historic settlements extracted from open gazetteers, such as the Gazetteer of the World. The team also plan to create a historical base map server, a gazetteer web mapping application and website and a program which generates a dump including the sources of information for each location. An API which allows the user to search the database of historical information has already been created.
Dr Southall concluded the seminar by noting that geo-semantic methods are generally inferior to geo-spatial methods, but are necessary in cases such as this when textual descriptions are all that is available and old maps which do exist tend to be inaccurate. Further information about PastPlace and access to the API can be found at www.pastplace.org.
(MSc in GIS at the University of Edinburgh)