Introduction to GIS

Dr. Huidae Cho
Institute for Environmental and Spatial Analysis...University of North Georgia

1   What is a GIS?

A GIS is composed of five interacting parts that include hardware, software, data, procedures, and people.

Law and Collins (2016)

A GIS is a Geographic Information System.

  • Captures, stores, manages, and visualizes geospatial data
  • Performs geospatial analysis
  • Makes maps

2   GIS definitions

GIS is a powerful set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes.

Burrough and McDonnell (1998)

A geographic information system is a facility for preparing, presenting, and interpreting facts that pertain to the surface of the earth.

Tomlin (1990)

A GIS is an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information.

ESRI (1990)

A geographic information system (GIS) is 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 data... In a sense, a GIS may be thought of as a higher-order map.

Star and Estes (1990)

3   GIS “terrain”


4   Various GIS packages

4.1   Esri ArcGIS

Proprietary $$$

User friendly

Commercial support

User friendly


Waiting for fixes

Windows only

4.2   QGIS

Open source $0

User friendly

Large user base

400 plugins

Work with GRASS GIS

Multiple platforms


Open source $0

Clunky UI

Scientists and developers

350 scientific modules and addons

Multiple platforms

4.4   MapWindow

Open source $0

User friendly

Windows only

5   Who uses a GIS?

  • Scientists
  • Engineers (e.g., hydrologic & hydraulic modeling)
  • Business analysts
  • Sales (e.g., traveling salesman problem)
  • Service
  • Marketing
  • FEMA (e.g., flood insurance)
  • Counties (e.g., facility management)

6   Collecting spatial data

gps.png remote-sensing.png remote-sensed-data.png

7   Layers


8   Data types

8.1   Vector


  • Points (e.g., trees, street lights)
  • Polylines (e.g., roadways)
  • Polygons (e.g., building footprints)
  • Scalable

8.2   Raster


  • Cell-based
  • For example
    • Temperature
    • Wind speed
    • Elevation
  • Resolution
  • Aggregated
  • Unscalable

8.3   Imagery


  • Remote-sensed data
  • Multiple bands (e.g., R, G, B)
  • Basically raster type

9   Attributes

“Information about spatial data” (metadata) makes a GIS more powerful.

map-with-attributes.png vs. map-without-attributes.png

10   Exercise: ArcGIS Online web map

Let’s create a new ArcGIS Online web map using some shapefiles in