There
have been so many attempts to define GIS that it is difficult to
select one definitive definition. There are as many as 11 different
definitions. This veriety can be explained by the fact that any definition
of GIS will depend on who is proposing it, and their background and viewpoint.
And these definitions are likely to change quickly as technology and applications
develop further. Some of the definitions are reproduced here again
:
-
Toolbox-based definitions:
"GIS is a decision support
system involving the integration of spatially referenced data in a problem
solving environment" ( Cowen 1988)
"GIS is an automated set
of functions that provides professionals with advanced capabilities for
the storage, retrieval, manipulation and display of geographically located
data" ( Ozemoy, Smith and Sicherman 1981)
In general, the definitions of
GIS covers three main components : 1) GIS is a computer system
with hardware, software and appropraite procedures 2) GIS uses
spatially referenced or geogrphical data and 3) GIS carries out verius
management and analysis tasks on these data, including their input and
output. In fact, the Department of Environmtment ( 1987 ) lists
the capabilities that a "well designed GIS" must be able to
provide as follows :
-
To give quick and easy access
to large volume of data ( spatial and non-spatial)
-
To select detail by area or theme.
-
To link or merge one data set with
another.
-
To analyse spatial characteristics
of data.
-
To search for particular characteristeics
or feature in an area.
-
To update data quickly and cheaply
and
-
To model data and assess alternatives.
-
To output the data tailored to meet
particular needs.
Thogh different definitions
stress on different elemants of GIS, it is perhaps the nature of
the data used and attention given to the processing and interpretation
of these data, that should lie at the centre of any definitions.
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