he overlaying of 
sity, land cover 
on network) for 
rm scale. In a 
GIS is geocoded 
lar format with 
georeferenced 
f methodological 
in image format; 
images) brought 
James and Martin 
observations and 
tial scientists 
than has even 
ovide a means of 
rry out complex 
mputerized data 
0's and 1960's 
f creating and 
problem solving 
rs, vast amounts 
and efficiently, 
nalyzing complex 
ionships between 
ble. It was in 
tive revolution" 
systems and GIS 
that has as its 
se composed of 
nates, and the 
digitally with a 
be viewed as a 
2 of related 
r use in solving 
nnment (fig. 1). 
ng large volumes 
sources (Marble, 
Figure 2 
Dangermond (1984, p. 1-26) has identiiied a number 
of advantages of using Geographic Information 
Systems in spatial analysis, they include: 
1) Data maintained in a physical compact form 
(e.g. the magnetic file). 
2) Data can be maintained and extracted at a lower 
cost per unit of data handled (i.e., automated 
versus outmoded manual data retrieval). 
3) Data can be retrieved with much greater speed. 
4) Various computerized tools allow for a variety 
of types of manipulation including, map measurement, 
map overlay, transformation, graphic design and data 
base manipulation. (These operations would be cost 
and time prohibitive in a manual setting.) 
5) Graphic and nongraphic (i.e. tabular and 
descriptive information) can be merged and 
manipulated simultaneously in a "related" manner. 
6) Rapid and repeated analytic testing of