An Introduction to�Geographic Information Systems (GIS)�

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Michael A. Reed

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Glendale College

Geography Department

Geographic information technologies

• Technologies for collecting and dealing with geographic information
• Three main types:
• Remote sensing
• Global Positioning System (GPS)
• Geographic Information System (GIS)

Remote Sensing

LANDSAT IMAGE OF LAS VEGAS

Remote Sensing

LANDSAT IMAGE OF LAS VEGAS

Remote Sensing

LANDSAT IMAGE OF LAS VEGAS

Global Positioning Satellite (GPS)

What is GIS?

• Stands for "geographic information systems"
• Definition: a system for the input, storage, manipulation, and output of geographic data
• a specialized "information system”
• information systems are used to work with (manipulate, summarize, query, edit, visualize) information stored in computer databases
• utilizes spatial indexing of information to track what is where on the Earth's surface

GIS Hardware

• Hardware like any other computer
• Keyboard, CPU, display monitor, cables, Internet connection
• With some extra components perhaps
• Maps come on big paper
• Need big printers and plotters to make map output from GIS
• Need big devices to scan and input data from maps to GIS
• Digitizers, scanners

GIS Software

• A GIS is also a type of software� (computer program)
• The user combines the software with his or her data and performs various analytical and mapping functions
• There are many different GIS software vendors, but ESRI (Environmental Systems Research Institute) has achieved market dominance.

GIS Functionality

• Common GIS tasks:
• Keep inventories of what is where
• Create high quality maps quickly
• Manage properties, facilities
• Judge the suitability of areas for different purposes
• Help users make planning decisions
• Make predictions about the future (modeling)
• Track changes in land use over time

How Do GIS Work?

What is important is the kind of information that's stored:

• Information about what is where:

Spatial Data + Attribute Data

• GIS software combines the two for analysis and display; space becomes an indexing system

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Space as an indexing system

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Settlements

Admin.

Units

Reference �Grid

Rivers

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Longitude

Latitude

List and Tables

Traditionally information is organized in lists, �maps add information about the “where” of the data

The Power of GIS: �Exploring Relationships

• Based on geographic location and proximity, GIS makes connections between activities and phenomena
• Looking at data geographically can often suggest new insights and explanations
• These connections are often unrecognized without GIS, but can be vital to understanding and managing activities and resources
• For example, we can link pollution sources with disease patterns

Combining data sets

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Pollution Sources

Leukemia Cases

Information about “where” allows us to combine heterogeneous data sets

GIS Layering

Contributing disciplines and technologies

• Geography
• Cartography
• Remote Sensing
• Surveying
• Geodesy

• Statistics
• Operations Research
• Computer Science
• Mathematics
• Civil Engineering

Application Areas

• Utilities
• Marketing and Economics
• Transportation
• Urban planning
• Health provision
• Epidemiology
• Demography
• Social sciences and humanities

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• Natural resources management
• Ecology
• Climatology
• Global change research
• Oceanography
• Famine early warning
• Navigation
• Emergency response

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Natural Resource GIS

Thematic mapping

Public Utility / Hydrology

High Quality �Map Display

Employment Opportunities

Salary Survey from GISjobs.com

U.S. Responses: 13984 

Average Salary: 42,420

GIS is a growing field with a demand for qualified geographic professionals who are paid high wages and work for public agencies and private companies. Most GIS technicians and managers have a four-year degree in geography or another discipline and have taken a number of GIS courses.

Employment Opportunities

AVERAGE NATIONAL SALARIES FOR DIFFERENT GIS POSITIONS. SOURCE: INDEED.COM, MARCH 2016.