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Geographic Information Systems Geographic
Information Systems A
geographic information system (GIS) is a computer-based system used
for the storage GIS
data are usually stored within separate files as “layers,” with each
layer containing one type of feature, such as vegetation types or rivers. What all the layers have in common is that
each data layer contains references that locate, or relate, that information
to exact points on the surface of the Earth.
GIS allows you to create maps using as many data layers as you
choose, and the data layers are overlaid on top of one another. For example, you can create a map of North
America that shows the names of all the states and provinces, and overlay
on top of that the locations of all the rivers in North America, and
on top of that the locations of a particular peregrine falcon that was
tracked over a 6-month period. You
can then use GIS analysis tools to examine the relationship between
the bird locations and the presence of rivers.
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analysis of “spatial” data, meaning data that are associated with particular
locations. Bird location data are an example of “spatial data.”