Geography Reference
In-Depth Information
butes, such as feature type, and up to eight kinds of demographic data
from three different censuses. Geographic location, recorded as points
rather than polygons in the DGSD, is simply one kind of atribute, though
the DGSD holds it in a separate point location table.
hat is, in distinction to a classic gazeteer data model such as the
Alexandria Digital Library (ADL), the DGSD encodes historical events
in an offset historical instance table separate from the tables that record
entities and atributes.
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And, unlike an instance-based gazeteer like the
CHGIS, which requires a new entry in the main table for each historical
change as well as entries in other related tables, the DGSD records only
one unique entity for each historical place.
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Each entry in the historical
instance table records a temporally bounded and stable piece of informa-
tion that refers to a time span during which a given characteristic of a par-
ticular entity - such as its name, rank, population, or parent - remained
the same. Each entry in the historical instance table is linked with an
entry in the entity table. All of the atributes of each entity are temporally
referenced to the extent that the source material permits.
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he DGSD
design, with its historical instance table offset from the entity table, offers
a potential way forward for designing historical gazeteers of frequently
changing places, while the ofset atribute table also allows future us-
ers to easily integrate additional information about Song jurisdictions.
In addition, using this approach, geolocations imported from C HG I S ,
CCTS, and Hartwell and associated with only one instance of an entity
can be readily identified and associated with all of its other instances. For
instance, Ping
平
zhou
prefecture was named Wangkou
王口
stockade
and Huaiyuan
懷遠
county at different times during the Song. However,
since it remained conceptually the same place throughout the era, it is a
single DGSD entity associated with seven entries in the historical instance
table and a single geolocation in the point location table.
HGIS Analysis Case 1: The Politics of
Territory in Song Dynasty China
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During the Song era, imperial authority expanded, while the aristocratic
class dissolved and the military apparatus atrophied, replaced by a meri-
tocratic civil bureaucracy. The cultivation of new strains of fast-ripening
