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What is GIS?
Simply
put, a GIS combines layers of information about a place to give you a
better understanding of that place. What layers of information you combine
depends on your purpose—finding the best location for a new store, finding
homeowner information, analyzing environmental damage, viewing similar
crimes in a city to detect a pattern, and so on.
Mapping Where
Things Are
GIS let's people map where things are and lets you
find places that have the features you are looking for and to see where to
take action.
- Find a feature—People use maps to see where or what an individual
feature is.
- Finding patterns—By looking at the distribution of features on the map
instead of just an individual feature, you can see patterns emerge.
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This map shows the location of man-made objects
such as buildings, antennas, and towers, as well as landscape features
that can pose dangers to aircraft leaving or approaching airfields. |
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Frame the Question
Start your GIS analysis by figuring out what
information you need. This is most often in the form of a question:
- Where were most of the burglaries last month?
- How much forest is in each watershed?
- Which parcels are within 500 feet of this liquor store?
- How close a drug arrest was to a school property?
- How many and what kind of crimes occured in your neighborhood?
Be as specific as possible about the question you
want to answer. This will help you decide how to approach the analysis,
which method to use, and how to present the results. |
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This map shows the Riverboat at Casino Aztar. The
green outlines are property boundaries which contain information like
address, lot size, owner name, etc. |
- Improve organizational integration.
- Make better decisions.
- Make maps.
Real-world examples:
Evansville/Vanderburgh County
Improve
Organizational Integration
One of the main benefits of GIS is improved management
of your organization and resources. A GIS can link data sets together by
common locational data, such as addresses, which helps departments and
agencies share their data. By creating a shared database, one department can
benefit from the work of another—data can be collected once and used many
times.
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Make
Better Decisions
The old adage "better information leads to better
decisions" is true for GIS. A GIS is not just an automated decision making
system but a tool to query, analyze, and map data in support of the decision
making process.
For example, GIS can be used to help reach a decision
about the location of a new housing development that has minimal
environmental impact, is located in a low-risk area, and is close to a
population center. The information can be presented succinctly and clearly
in the form of a map and accompanying report, allowing decision makers to
focus on the real issues rather than trying to understand the data. Because
GIS products can be produced quickly, multiple scenarios can be evaluated
efficiently and effectively.
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Make Maps
 For
simplicity's sake we often call GIS "mapping software." We most often
associate maps with physical geography, but the map to the right
demonstrates that GIS is flexible enough to map any kind of terrain, even
the human body. GIS can map any data you wish.
Making maps with GIS is much more flexible than
traditional manual or automated cartography approaches. A GIS creates maps
from data pulled from databases. Existing paper maps can be digitized and
translated into the GIS as well.
The GIS-based cartographic database can be both
continuous and scale free. Map products can then be created centered on any
location, at any scale, and showing selected information symbolized
effectively to highlight specific characteristics. A map can be created
anytime to any scale for anyone, as long as you have the data.
This is important because often we say "I see" to mean
"I understand." Pattern recognition is something human beings excel at.
There is a vast difference between seeing data in a table of rows and
columns and seeing it presented in the form of a map. The difference is not
simply aesthetic, it is conceptual—it turns out that the way you see your
data has a profound effect on the connections you make and the conclusions
you draw from it. GIS gives you the layout and drawing tools that help
present facts with clear, compelling documents.
Source: GIS.com and Evansville GIS Department |
