However, the true power of maps typically remains underused
for geographic knowledge discovery unless one combines a geographic information
system (GIS) to OLAP technology.
The.Power.of.Maps
Map data are the raw material to produce the geographic information that leads to
knowledge about the position, extent, and distribution of phenomena over our territories.
Such phenomena are counted by thousands and include insect territorial
expansions, environment-health correlations, land-use evolution, 911 vehicle tracking
and watershed analysis, to name a few. Visualizing geographic phenomena on
maps facilitates the extraction of insights that help to understand these phenomena.
Such insights include spatial characteristics (position, shape, size, orientation, etc.),
spatial relationships (adjacency, connectivity, inclusion, proximity, exclusion, overlay,
etc.), and spatial distribution (concentrated, scattered, grouped, regular, etc.).
When we visualize a map displaying different regions, we can compare. When we
visualize different maps for a same region, we can discover correlations between
phenomena. When we visualize the map of a region for different epochs, we can
see the evolution of the phenomena. When we use maps, we often get a better understanding
of the structures and relationships contained within spatial datasets than
using simple tables and charts.
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