What is a GIS?
One of a Set
Geospatial technologies are technologies for collecting and dealing with
geographic information. There are
three main types:
Global Positioning Systems
Remote Sensing
Geographic Information Systems
Defining GIS
• Different definitions of a GIS have evolved
in different areas and disciplines
• All GIS definitions recognize that spatial
data are unique because they are linked to
maps
• A GIS at least consists of a database, map
information, and a computer-based link
between them
One Definition: A GIS is an
information system
"An information system that is designed to
work with data referenced by spatial or
geographic coordinates. In other words, a
GIS is both a database system with specific
capabilities for spatially-referenced data, as
well as a set of operations for working with
the data" (Star and Estes, 1990, p. 2).
Paul Bolstad’s Definition
“a computer-based system to aid in the
collection, maintenance, storage,
analysis, output, and distribution of
spatial data and information”
A Current World Definition:
GIS is 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”
We usually understand GIS to be computerfacilitated system
GIS is NOT only software/hardware
Also includes:
•Trained personnel
•Supporting Institution
•Protocols for use
Why Learn GIS?..... Because GIS is Everywhere
Why GIS in a Natural Resources
Curriculum?
• Resource
depletion/degradation
• Climate change
• Urban-Rural interface
impacts on resources
• General increase in
problem complexity
• Public’s demand for
better information
• Improved capabilities
Why computerize manual methods?
•To bring together data from multiple sources (synthesis)
•Analytical power
•measure distance, density, area
•overlay and buffer
•adjacency and proximity
•vicinity (neighborhood)
•networks
•Flexibility
•Output Quality
• Expanded capabilities
- do the heretofore
impossible
• Improved efficiency reduce speed of
analysis 10-fold or
more
Historical Setting and GIS Evolution
Manual Mapping for 8,000 years
The US Department of Labor identifies Geotechnology
as one of the “three most important emerging
and evolving fields” of the 21st century
(along with Biotechnology and Nanotechnology)
Computer Mapping automates the cartographic
process (70s)
Spatial Database Management links
computer mapping with database capabilities (80s)
Map Analysis representation of relationships
within and among mapped data (90s)
Multimedia Mapping full integration of GIS,
Internet and visualization technologies (00s)
Visualizing Spatial Relationships
Phosphorous (P)
What spatial relationships
do you SEE?
…do relatively high levels
of P often occur with high
levels of K and N?
…how often?
…where?
Multivariate Analysis
The Precision Ag Process (Fertility example)
As a combine moves through a field it 1) uses GPS to check its location then
2) checks the yield at that location to 3) create a continuous map of the
yield variation every few feet. This map is
Steps 1) – 3)
4) combined with soil, terrain and other maps to
derive 5) a “Prescription Map” that is used to
6) adjust fertilization levels every few feet
in the field (variable rate application).
On-the-Fly
Yield Map
Step 4)
Farm dB
Cyber-Farmer, Circa 1992
Zone 3
Zone 2
Zone 1
Prescription Map
Step 5)
Variable Rate
Application
Step 6)
3-D Visualization Approaches
Image Draping -- is an established technique in GIS.
Draping a
topographic or thematic map onto a 3-D terrain surface is effective but
relies on abstract colors, shading and symbols.
“Map Abstraction”
SportsTracker (MapTrek, 9/98)
Visualizing Landscape Impacts (GIS Rendering)
(Berry)
Visualizing Landscape Impacts (Clear cut)
(Berry)
Visualizing Landscape Impacts (Water retention cut)
(Berry)
Geospatial Multimedia
…take pictures with a digital
camera or video recorder while
carrying a GPS with ‘track
logging’ then link the Lat/Lon
with each picture.
Digital Camera
 What (picture)
 When (time)
 When (time)
 Where (X,Y)
GPS Unit
Export to HTML and post to Internet
Pictures are “posted and linked” to a map
Google Earth (Killer App of 2005)
Vessel for Mapped Data— has brought Geotechnology to the masses; not a GIS but
digests map data for 3D display with satellite imagery of the globe as backdrop
…and/or import GIS data layers into Google Earth
Geo-tagged
Photos
(Wildfire Risk)
GIS Utility and Understanding
Philosopher’s Progression of Understanding—
 Data (all facts)
 Information (facts within a context)
…GeoExploration emphasizes tools for data access and
visualization (general user)
Mapping focus
Data/Structure and Analysis focus
 Knowledge (interrelationships among relevant facts)
 Wisdom (actionable knowledge)
…GeoScience emphasizes tools for spatial reasoning and
understanding of geographic patterns and relationships (application
specialist)