Great Britain Historical Geographical Information System (GBHGIS)
About the project
Our original work was entirely focused on historical statistics - on census reports, data on births, marriages and deaths, and on unemployment and poor law statistics. The resulting system, developed in London between 1994 and 1999, loosely linked a record of changing administrative boundaries, managed using ArcInfo software, to our existing database which held millions of statistical data values in hundreds of tables.
Since 2001, with funding from the UK National Lottery and JISC, we have built a completely new system designed both to remove limitations of the original system and to hold a much broader range of the content:
- Like any mainstream GIS, the original GBH GIS could hold information only about units whose locations we knew. There are a few historical units which appear, for example, in tax lists but whose location is unknown. There are a great many more whose boundaries have yet to be mapped. The core of our new system is a systematic list of all the units we know about - currently over 48,000 units, linked by over 150,000 relationships.
- This core system is not, strictly speaking, a GIS at all: it is implemented using database software, requires no locational data at all and is organised as an ontology, or "polyhierarchic thesaurus". Each unit can have any number of names, hierarchic relationships are held very flexibly, and we use a system of "date objects" which enable us to record changes as precise calendar dates, as years, or as strings of text such as "at least 1174 but possibly as early as 983".
- Although knowing boundaries is not compulsory, we use the spatial extension to hold over 40,000 boundary polygons, with dates, for many units. These polygons were created by our own earlier work, by Roger Kain and Richard Oliver's work at Exeter University on the boundaries of Ancient Parishes, and recent work we have done on Scottish parish boundaries. The system can use hierarchical relationships to infer approximate locations for units lacking boundaries.
- We have built another quite separate GIS, using open source MapServer software which holds complete sets of geo-referenced scanned images of Ordnance Survey one inch-to-the-mile maps of Britain, partly to put our boundary mapping in context. The ones used as base maps are: the 19th century First Series, the 1940s New Popular Edition and the inter-war Land Use Survey of Great Britain (this last set were funded by the Environment Agency and the Department for Environment, Food and Rural Affairs). There are additionally many more full and partial sets available to view. See map sets
- The system as a whole aims to be a comprehensive description of Britain and its localities. One way we achieve this is by including approaching 10m. words of text: of accounts of journeys around Britain, such as Celia Fiennes' Through England on a Side Saddle in the Time of William and Mary, cross-referenced by place to the rest of our system; over 90,000 entries from descriptive gazetteers published in the late 19th century, describing towns, villages and landmarks; and the main report from every census up to 1961.
- A large part of our statistical holdings are being moved to this new structure. Most collections of computerised statistics, including our own old database, are divided into many separate tables and are designed mainly to allow researchers to download these datasets for further analysis. Our new system holds all statistical data values in a single column of a single table, with many millions of rows, enabling them to be used very flexibly for mapping, graphing and reconstructing the source table.
- That last feature is made possible by a metadata framework developed by the Data Documentation Initiative. The extent of our support for open standards is probably unique among historical GIS projects. We also support Dublin Core, the Alexandria Digital Library Gazetteer Content Standard, and the Ethnologue and Linguist codes for identifying the languages of place-names. Our creation of maps for the web follows Open GIS Consortium standards.
- The initial system was created using Oracle and Oracle Spatial, and the collection of original data tables in their traditional format continue to use this software. However, during the JISC funding the Vision of Britain sytem was moved to Postgres and PostGIS as it was felt this open-source software had developed sufficiently to cope with the demands of the system.
The central focus of the project is on the development of our GIS as a national resource. However, there have been a series of associated major research projects for example, an analysis of the impact of high unemployment in inter-war Britain on both short-run infant mortality rates and long-run life expectancy. We also undertake consultancy work.