Geographic Information Systems:
Putting it all together
The thing about GIS
Some examples of GIS online
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Maricopa County Assessors’ Office Interactive
Maps
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Yavapai County Interactive GIS
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http://www.maricopa.gov/assessor/gis/map.html
http://mapserver.co.yavapai.az.us/Interactive/map.asp
USGS – Various web mapping applications
related to environmental studies and
management
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http://rockys20.cr.usgs.gov/RMMC/Main/hud.html
What GIS is NOT:
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Maps
A software system
It is not GPS (Global
Positioning System)
Often these are components of an effective use of a
geographic information system.
What is a Geographic Information System
(GIS)?
National Science Foundation:
A computer-based system for capture, storage,
retrieval, analysis and display of spatial
(locationally defined) data
Definition 1: a tool box for data capture
graphical
digitize
scan
convert
State
Alabama
Alaska
Arizona
Apportionment
Population
4,461,130
628,933
5,140,683
nongraphical
format
manual entry
Definition 2: an information system for
data management
Storage
Retrieval
Querying:
Retrieving a
particular subset
of data
updates
Definition 3: manipulation & analysis
river
factory
With the type
of flood that
occurs on an
average once
in a hundred
years, what
area would
flood?
If there was a
chemical
explosion, how
far would the
toxic chemicals
spread?
Definition 4: an approach to science
“The generic issues that surround the use of GIS
technology, impede its successful implementation, or
emerge from an understanding of its potential
capabilities”
(Goodchild, 1992)
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GIScience is research both on and with GIS
GISystems changed the entire approach to
spatial data analysis

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Technology has become simpler and easier to use
GISystems and GIScience has crossed disciplinary
boundaries
GISystems, GIScience and GIStudies

GISystems
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Emphasis on technology and tools
GIScience

Fundamental issues raised by the use of GIS
and related technologies (e.g.)



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Spatial analysis
Map projections
Accuracy
Scientific visualization

GIServices
GIStudies

Systematic study of the use of geographic
information
Definition 5: a display
100 year
flood zone
area affected
by chemical
explosion
Definition 6: a multi-billion dollar
business
“The growth of GIS has been a marketing
phenomenon of amazing breadth and depth and
will remain so for many years to come. Clearly,
GIS will integrate its way into our everyday life to
such an extent that it will soon be impossible to
imagine how we functioned before”
(Clarke)
…a multi-billion dollar business

August 2004, Geospatial technology is listed by the US
Department of Labor as one of the three most
important emerging fields.

GIS industry is worth over $7 billion


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Software
Data
Services
Publishing
Education
What is Geospatial Technology?

Computer Cartography
Data Entry: Enter 2218 locations into spreadsheet
Data Processing: Add spatial data to spreadsheet: full
addresses or latitude and longitude coordinates
Data Analysis: Classification, range grade data, overlay
analysis, create visual variables
Every detailed map
=
hours of work
Cartography by Conrad Brewjo
What is
Geospatial Technology?

Global Positioning Systems
What is
Geospatial Technology?

Remote Sensing
30m, LANDSAT
1m, IKONOS
http://www.geo
place.com/hott
opics/groundze
ro/default.asp
http://www.geo
place.com/gw/
2002/0201/020
1wtc.asp
http://visibleearth.nasa.gov/cgi-bin/viewrecord?7846
GoogleEarth! http://earth.google.com
…a multi-billion dollar business

Critical to the growth of the industry

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1. Federal Government Data
2. Successful advocate of itself at all levels and internally

3. GUI software and automation

4. Merged with parallel technologies to become
“geospatial technology industry”
Definition 7: a societal role
GIS as “organized activity by which people
measure and represent geographic
phenomena, and then transform these
representations into other forms while
interacting with social structures”
(Chrisman 1999)
Societal Role…

Organized collection of

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Hardware
Software
Data
People
Procedures
Networks
Software
People
Data
Procedures
Hardware
Societal Role…

Moral and ethical implications



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Favors generalization
Not always neutral
Technological rather than human-need
focused
Maintains and extends societal power
structures
Functional definition of GIS:
A system for dealing with space-time
data, that has the following functions:

Data input

Data management

Data manipulation and analysis

Data reporting
Example: a new bus route

$$$ for bus service improvements

How could GIS be used to help determine
the best location for a new bus route?
Where can we get relevant data?
Population density
US Census bureau,
topographic maps, town
records, aerial photographs
Potential ridership
Marketing questionnaire,
demographics
Existing bus routes
Valley Metro
Distance willing to walk
Marketing questionnaire
Environmental impact?
Air quality measurements,
estimates of pollution in
microclimates
Key GIS elements

Organize each type
of information into
its own data layer
Key GIS elements

Set up data so it
overlays correctly
More key elements:

Analysis


Create a buffer of ¼
mile around existing
bus routes
To learn more, take
advantage of links
between locations and
attributes
GIS links location and attributes
Location files:
store info about boundaries,
locations, adjacency
links
Attribute files:
store info on nonspatial characteristics
of the features
In summary …


GIS allows for spatial data acquisition,
storage, manipulation, and analysis
Output can be many different forms!