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Locating socio-economic activities with GIS in Chines cities
Zhengdong Huang Ian Masser
(hzhd@itc.nl) (masser@itc.nl)
ITC, P.O. Box 6, 7500 AA Enschede, the Netherlands
Abstract
In building urban information systems, it is important to identify the spatial locations of socioeconomic
phenomena. In Western urban areas, street addresses, street intersections and postcodes
have been widely used for locating socio-economic activities. However, these methods may not
operate equally well in developing cities, partly due to the inconsistent and incomplete referencing
bases (street address and postcode), and partly due to different ways of address expressions. This
paper discusses these problems and proposes possible solutions. The existing practical referencing
systems in different sectors are briefly introduced. Two basic schemes of location references, the
name-based and the street-based scheme, are considered with respect to their possible applications in
China. Taking Wuhan, a metropolitan city in China, as a case, experiments are carried out to show the
possibilities of the proposed methods. To implement the schemes, data consistency and completeness
have to be achieved within organizations, and close cooperation is needed among public agencies that
have control over the base referencing data.
Introduction
In urban areas it is important to identify the spatial locations of socio-economic activities, the process
of which is called location referencing. Many location referencing methods have been developed and
implemented in different fields, e.g. street address and postcode. The TIGER/line files developed by
the Census Bureau of the US contain line, landmark and polygon features that provide locational
references for field staff and map users (The Bureau of the Census, 1997). In urban areas the street
address ranges have been widely applied for address matching. The postcode system from postal
service is another important referencing base that has been utilized for location referencing in travel
and activity survey. From a geographical point of view, postcodes are becoming a widely used and
general method of describing the position or location of places, areas or objects on the earth (Raper et
al, 1992). A postcode may be designed to indicate a very small area or even an individual property,
such as the cases of Postal Address File (PAF) in the UK and the ZIP+4 in the US. In a detail level,
postcodes and street addresses are linked with the properties they represent, which can provide more
flexible means of location referencing.
The methodologies of location referencing have been discussed from different perspectives. The
Geographic Information System (GIS) itself is a spatial referencing system for geographic phenomena.
Laurini and Thompson (1992) declare that positioning objects in spatial referencing systems involves
several considerations, such as the geometric character of the reference system, the measurement
metrics, nature of the origin, and discrete or continuous references. The referencing bases in GIS
generally refer to either coordinate or grid system. In urban applications, more attention has been
given to relative referencing methods that can locate socio-economic activities within existing spatial
bases. Goodwin et al (1995) have summarized several location referencing methods, i.e. link ID, linear
referencing system, coordinate system, street addresses, cross-street matching, and their combinations.
Apart from the coordinate system, these methods require only names or numbers, rather than
coordinates, to locate the sites.
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