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Geographic Information Systems |
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Geographic information systems were a part of the information technology revolution of the 1980s. They brought together a number of previously separate technologies and promised to transform the provision of information to governments, businesses and utilities, as well as to academics and other private citizens. A geographic information system locates information in geographic space and has five elements: data capture; data preparation; data storage; analysis and output. As such, it brings together the interests of data collecting organizations such as national censuses, databases, for example Ceefax, geographers and other spatial analysts, and cartographic organizations in public and private sectors. Indeed, one of the problems has been the proliferation of different systems as specialized organizations extend their areas of interest: for example, the US census developing map production or Bartholomews setting up databases to simplify map preparation.
Ideally, a geographic information system allows an organization or individual to access a large variety of data, which has been collected and updated by private and/or official sources, to process it in ways they specify and to output it as maps, diagrams or tables. The problem is that different data-collecting organizations use different spatial bases for different purposes. Some data may be continuous, some may relate to points or lines and much relates to areas which vary in scale, shape and regularity. As a result, even simple tasks such as bringing together two kinds of data and mapping their association pose complex problems. The large databases and heavy processing demands require more sophisticated systems to be run on mainframe computers, though desktop machines can be used for simpler systems. No doubt the technical problems will be overcome, but the standardization of areas between organizations is a slow process. At present the demands of assembling data and presenting it in graphic form is sufficiently demanding to satisfy most users and few systems offer much ability to carry out statistical analyses of the resulting patterns. But, in spite of reservations, ease of access to information has improved dramatically. A pioneer British system of the mid-1980s, the Domesday disk, claimed to offer any purchaser more geographic information on one laser disk than had previously been available to any government department. In future, it is likely that more and more varied information will become available, but it is probable that access will be determined by cost factors resulting from the expense of building up these systems and the value of up-to-date information. PS
Further reading D. Martin, Geographic Information Systems and their Socioeconomic Applications. |
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