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Geospatial Data / Data Download / Using the Data
Using the Data
Introduction to GIS Software
Welcome to the exciting world of GIS! GIS is a powerful system that combines
visual geographic information--that is, maps--with the computer software
to interpret and analyze that information. Like traditional paper maps,
GIS maps provide us with images of our cities, counties, and states along
with the usual geographic information like political boundaries, roads,
or bodies of water. But instead of the what-you-see-is-what-you-get concept
of the paper map, GIS maps can store much more information about the map's
features, or attributes, in a separate database, a database that can be
stored on your computer's hard drive or accessed by linking to a Web site.
With a GIS map of Maryland, for example, you could point your cursor
at the various Maryland counties, click your mouse button, and information
about those counties--such as total area, population, etc.--would appear
in a dialogue box on your computer screen. What's more, the different
kinds of information available in a GIS map are stored in layers that
can be turned on or off depending on your needs. If you were looking for
parks to visit in Maryland, you could turn on the data layer that contains
information about parks. If instead you are interested in power line corridors,
you could turn off the parks layer and switch on the power line layer.
GIS maps also give you the power to define your searches for geographical
information. Say you were looking for the most direct route to travel
by car from one end of your county to the other. You would access a GIS
map of your county and switch on the roads layer. But suppose you then
decided that you wanted the fastest route from one end of your county
to the other. You could query the map's database to display only those
roads that are four lanes wide or wider. You can even zoom in to get a
closer look at a specific area on the map or pan across the map to find
exactly what you are looking for!
Quick Start Guide
for ArcExplorer
Quick Start Guide
for ArcView
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