Download What is GIS? - Oklahoma 4-H

GIS and Layers
Developed by Oklahoma 4-H
Beginnings of GIS

Began in the 1960s

Use was mainly in the public sector

Has roots in cartography and mapping

Major influence on geography in the 1980s
and 1990s
Definition of GIS

Geographic Information System
• ESRI defines GIS as: A collection of
computer hardware, software, and
geographic data for capturing,
managing, analyzing, and displaying all
forms of geographically referenced
information.
Layers



Layers are a “slice of the geographic
reality in a particular area” (ESRI)
They are similar to a map legend
Layers may describe physical,
biological, cultural, demographic,
scale, etc. characteristics

For Example:
• We have three maps (or layers) with
yearly rainfall, tree species, and soil
type for a specific area.
• By overlaying these maps, we could
determine if the amount of yearly
rainfall has an effect on the type of tree
that grows in certain soils.
Essentially GIS uses different layers to
show the relationships between data.
Yearly Rainfall
Tree Species
Soil Type
ESRI example of GIS map and its
layers
Components of GIS

Hardware
• Computer

Software
• Computer program

Data
• Collected, bought, or free
Uses of Data
Find features or patterns
 Quantities and density maps
 Changes in a specific area
 Anticipating a change (natural
disaster preparedness)
 Deciding or evaluating a course of
action

How is it used?
Tracking the spread of disease
 Mapping soil moisture
 Trends in an evolving storm
 Mapping Storm Water systems
 Public road inventory
 Precision Agriculture

Tracking the spread of the West
Nile virus from ESRI Map Book vol.
19
Track of 2004 Hurricanes in Florida
and Wind Speed, ESRI Map Book
Vol. 21
Mapping soil moisture from ESRI
Map Book Vol. 21
Wastewater collection system from
ESRI Map Book Vol. 21
Predicting traffic problems from
ESRI Map Book Vol. 16
Precision Agriculture from ESRI
Map Book Vol. 20
Maturity Map
Maps are for Brown Rice
Red is High; Purple is Low
Protein Map
Detailed Map
What are other
uses you can
think of?

Link to ESRI map books for real life
GIS maps:
http://www.esri.com/industries/plan
ning/success_stories/map_book.html
Activity

If given the following layers, what
inferences or assumptions can you
make from them?
• Map of the U.S. with state capitals
• Map of the population density
• Map of interstate highways
• Map of rivers in the U.S.
• Average farm size in acres
Map of United States and State
Capitals
Interstate Highways
Major Rivers
Capitals, Rivers, Highways
Population Density from 2000
Census
Capitals, Rivers, Highways,
Population
Oklahoma with Highway, Rivers,
Population Density
Average Size of Farms in 2002
Farm Size, Capitals, Highways,
Rivers
Oklahoma Farm Size, Highways,
Rivers
All maps are from the National Atlas
website located at:
www.nationalatlas.com
This site allows you to use different
layers to create maps.