Database Reference
In-Depth Information
parks, and so on. The list is almost limitless. The important factors of any digital
feature model are identity, a means to uniquely identify the feature; location, a means
to locate the feature in the landscape (normally achieved via vector geometry associ-
ated to a coordinate system); classification, which specifies the nature of the thing
being represented; and attributes, which may include relationships to other features.
If one is precise, then the locational information and classification are also attributes,
although they are of special interest.
Digital feature models lend themselves to representation as Linked Data within
the Semantic Web.
3.5 A BRIEF HISTORY OF GEOGRAPHIC INFORMATION
To understand the current state and usage of GI, it can help to understand its history as
past decisions have an impact on the shape of today. GI in its widest sense has a history
that goes back way before the age of computers to the waggle dance: where bees have
communicated the location of pollen through their movement. But, this topic need
only concern itself with the use of GI within computer systems and the Web.
Giving a brief history of GI usually means giving a history of the professional
aspect of GI, which, to respect tradition, we also do. But, there is also a more infor-
mal use of GI, whose own history is also worthy of telling and indeed becomes more
relevant as time progresses. The reader should therefore excuse the fact that two
histories are presented with only a small degree of interaction between them. Part of
the future for GI will be to bring these two stories together.
3.5.1 a t
raditional
s
tory
: Gi
and
Gis
The standard history of GI is not really specifically about GI, but about GIS—
Geographic Information Systems. GIS explicitly recognize that GI needs special
treatment and provide technologies for performing specialist analysis. It is also easier
to tell the story of GIS: It is easy to search the Web for a definition of GIS, but search-
ing for a definition of GI is much less fruitful; at the time of writing, Wikipedia, that
global penny bazaar of knowledge, had no entry for GI. It may even be that the term
GI did not exist independently before GIS.
3.5.1.1 Geographic Information Systems
The first accepted reference to GIS is the Canada GIS built in 1963, as mentioned
by Longley et al. (2001). The important aspect of this system was the explicit rec-
ognition that computers, which in 1963 were very novel, could be used to perform
spatial analysis. The system was used to store maps that resulted from a survey of the
potential use of land for various purposes, such as agriculture or forestry. The system
developed such that it acquired the capability not only to hold the maps but also to
perform analysis on them through a series of fixed reports. This may seem primi-
tive by today's standards but was revolutionary for the time. The late 1960s saw the
U.S. Bureau of Census also developing a GIS to create a street gazetteer to support
the collation of census records. The U.S. and Canadian systems were not related but
shared certain common aspects in the manner in which they handled GI. Over time,
