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6
The previous chapter described the basic components of GIS and how it
operated, so now it’s time to start doing some things with that GIS data. Anytime you’ll be examining the spatial character of data, or how objects relate
to one another across distances, you’re performing spatial analysis. A very
early (pre-computer) example of this is Dr. John Snow’s attempt to solve
the mystery of several cholera-related deaths in London in 1854. Snow’s
analysis was able to identify an infected pump, which was the source of the
outbreak. At some point, Snow mapped the locations of the cholera deaths
in relation to the water pumps (Figure 6.1). This type of spatial analysis
Using GIS for Spatial Analysis
Database Query and Selection, Buffers, Overlay Operations,
Geoprocessing Concepts, and Modeling with GIS
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spatial analysis
examining the
characteristics or
features of spatial
data, or how features
spatially relate to each
other.
FIGURE 6.1 A version of John
Snow’s map showing locations
of cholera deaths and well
pumps.