Geographic Information Systems Geographic Information Systems
(GIS) are an area of IT application with a significantly
different history from forms of information system GIS deals
with the storage, representation and processing of spatial data.
Many forms of decision making are spatial in nature and
disciplines such as cartography have sought to represent spatial
relationships. In 1854 John Snow, an English doctor, attempted
to get a better understanding of the problem. He used a map of
London to plot the locations of the homes of Cholera fatalities.
He also marked the location of water pumps on the map. Using
this representation it became clear that those with cholera were
clustered around a particular pump. This supported the belief
that the disease was spread by contaminated water. Dr Snow asked
for that pump to be closed and the epidemic subsided. This
example indicates how locations plotted on a map could provide
information that wasn't obvious from an analysis of the non-
spatial characteristics of the p