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Integrating CHGIS with other Gazetteer Standards and Classification Systems. Merrick Lex Berman, Harvard Yenching Institute. PNC – ECAI, Guadalajara Dec 2001. research partners. Harvard Yenching Institute. Fudan University, Center for Historical Geographical Studies.
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Integrating CHGIS with other Gazetteer Standards and Classification Systems Merrick Lex Berman, Harvard Yenching Institute PNC – ECAI, Guadalajara Dec 2001
research partners Harvard Yenching Institute Fudan University, Center for Historical Geographical Studies ACASIAN, Griffith University Academia Sinica – Taipei, Inst for Information Sciences sponsor CHGIS Organization
location - point 1 to point 2 placename - “Shawmut” to “Boston” administrative status - township to county seat feature types – dirt road to paved road what are the temporal variables of “places?”
place being tracked over time independently changing variables
each place object has many “instances” of change over time: place objects – temporal instances
each placename record may have many sub-types, such as: character sets, transliterations, or pronunciations character sets transliterations placenames
Alexandria Digital Library (ADL) – Feature Type Thesaurus hydrographic features . seas . . oceans . . . ocean currents Bureau of Land Management, Taipei – NGIS cartographic elements feature classification schema
Alexandria Digital Library (ADL) Feature Type Thesaurus: physiographic features -cliffs hydrographic features -aquifers -drainage basins -streams --rivers ---rapids feature types - hierarchical model
each feature instance may have many “feature types” feature types may have many associated feature types and glosses associated feature types glosses feature types – relational model
a private residence is donated to a temple, affecting tax revenues both for the building and the fields under cultivation at different times the same place object may have different temporal instances of a particular feature type feature types change over time
a single building may have many functions over time, recorded with multiple “instances” of feature types: temporal instances to track changing features
tracking a building’s changing “feature types” associated feature types glosses feature types – changes over time
list of available Feature Type thesauri: 1 – Alexandria Digital Library Feature Types (1156 terms) 2 – River Research Group Feature Types (435 terms) 3 – Taiwan NGIS Feature Types (2000 terms) 4 – CHGIS (220 terms) cross-searching feature type thesauri
each system classifies its contents NIMA Classes: A – Admin Area H = Hydro L = Land Area P = Pop Place R = Road S = Spot T = Contour U = Undersea V = Vegetation rough classification for interoperability
hydrographic features search searching by rough class
list of available “hydrographic” Feature Types in each thesauri: 1 – Alexandria Digital Library Feature Types (158 / 1156 terms) 2 – River Research Group Feature Types (380 / 435 terms) 3 – Taiwan NGIS Feature Types (200 / 2000 terms) 4 – CHGIS (37 /220 terms) comparing contents among thesauri
Records in the unrelated thesauri Concordance table between thesauri concordance table
use ADL Feature Types as a basic standard for interoperable searching and Unicode (UTF-8) • specialized thesauri submitted to the testbed should include a linktable with: • - Feature Type definition • - Feature Type Enlgish language gloss • - Feature Type match to ADL type • - “locale” for the Feature Type • - date range for the Feature Type 3. testbed editor identifies ADL types with high numbers of submitted specialized sub-types 4. Testbed editor enlists help of submitters to identify concordances between their own Feature Types and those in other thesauri proposed actions
use ADL Feature Types as a basic standard for interoperable searching and Unicode (UTF-8) ISO – 8601 Date and Time Notation “with extension for older dates” • specialized thesauri submitted to the testbed should include a linktable with: • - Feature Type definition • - Feature Type Enlgish language gloss • - Feature Type match to ADL type • - “locale” for the Feature Type • - date range for the Feature Type Open GIS draft suggestion: 1) yyyy-mm-ddThh:mm:ss.sss or 1999-08-12T09:40:23.558 Where T = Time 2) Periodic events are indicated with a P then a value and unit measure, as in: yyyy-mmPunitY or 1980-06/2000-06/P1M 3) BCE dates take the letter “B” as a prefix, so B221 = BCE221. 4) Geologic dates in the distant past take the letters “K, M, G” as prefixes, meaning thousands, millions, and billions of years before the present, respectively. K16 = 16,000 years ago M120 = 120,000,000 years ago G3 = 3,000,000,000 years ago 3. testbed editor identifies ADL types with high numbers of submitted specialized sub-types 4. Testbed editor enlists help of submitters to identify concordances between their own Feature Types and those in other thesauri date formats proposed actions
CHGIS: China Historical GISProject website: fas.harvard.edu/~chgis