welcome to geog 070 intro to geographic information autumn session - 2005 instructor: gregory taff

Welcome to GEOG 070Intro to Geographic

InformationAutumn Session - 2005

Instructor: Gregory Taff

Autumn 2005 Gregory Taff 2

Lesson 1: Intro to Geographic Information


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Geography = Place names only?


World Population

The heavier the color, the more the population.


Population Growth Rate

The heavier the color, the higher the growth rate.


World Vegetation


Intro to Geographic Information

1.1 The “G” in GI (Geographic Information)

Geography – Patterns and processes of human and physical phenomena on the surface of earth.

Examples of geographic information:

•Location of Chapel Hill

•Interstate I40’s spatial pattern

•Distribution of world population density

•Urban sprawl/development of Raleigh over 100 years.


GI examples (cont.)

•Water quality of Michigan Lake.

•Water pipe lines in Orange county.

GI could be static, or dynamic, depending on how you collect and study GI.

-For the same object, for example, a car, its spatial position might change over time.

-For the same location, like chapel hill, you can study its population changes over time.


1-2 Variables in GIGeographic information involves: Location/Spatial information of objects

Objects: Points (air pollution monitoring station) Lines (the location of the length of a road) Polygons (the boundaries of a county) Pixel (from a satellite image)

Location/spatial information – coordinate system Latitude and longitude UTM State Plane

Attributes Income levels of census tract Air pollution levels at monitoring station Elevation of a topographic contour line


1-2 GIS Example – layers of data


Overlay (of data layers)


Change layers (here a 2002 satellite image)


Variables in GI

• GIS data can contain Z-values (elevation) – e.g. for an airplane

• Time – GI data usually will have a time stamp.

• Updates of census information in a census tract

• Land cover change of a plot of land (field may grow into forest).


Sources of GI

There are many ways we can obtain GI data. Popular ways –

• Surveying/Field work

• Remote Sensing

• Digitizing old maps

• Purchasing

• Get free data by downloading from Internet, copying from CDs borrowed from library.


1-3 Formats of GI

GI exists in many formats

-Paper maps

-Tabular data (weather station lists of city temperatures)

-Text (a description of a place)

-Digital format, necessary to copy/analyze using software.


What is GIS? GIS is built on the collective knowledge from geography, cartography, computer science, and mathematics. A GIS has many definitions depending on whom you ask. GIS as a Toolbox:

GIS is a powerful set of tools for storing and retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes. Peter Burrough, 1986

This definition emphasizes a set of tools designed to solve specific problems.

1-4 Geographic Information Systems


GIS as an Information System: A geographic information system is a spatial case of information system where the database of observations reflects spatially distributed features, activities or events, which are definable in space as points, lines, or areas. A geographic information system manipulates data about these points, lines and areas toretrieve data for queries and analyses. Ken Dueker, 1979 [edited by Taff].

The information system definition implies that GIS collects data, sifts and sorts them, and selects and rebuilds them to find the right information to answer a question.

GIS definition


Dueker’s definition only applies to the vector model of the real world, which represents the real world on a map as point, line, and area features. In fact, there is another model of the world, the raster model of the world, to which the definition does not apply. My preferred definition is a hybrid of both: “GIS is an information system that allows for capture, storage, retrieval, analysis and display of spatial data.”

Note that GIS is closely tied to the infrastructure that exists for creating spatial data – satellites, census protocols, weather stations, land survey techniques, and more.

GIS definition


Computer hardware Software Data management and analysis procedures

(this could be considered part of the software)

Spatial data People needed to operate the GIS

Components of a GISas defined by Heywood

This is a good test question!


Hardware: Digitizer, scanner,

PC, ETC.

SoftwareCommercial software –

Esri family, ArcGIS, Arcview, etc.

Data:Shape files, Coverage files,

Remote Sensing data,Census data, etc.

PeopleGIS specialists, analysts,researchers, technicians,

Operators, etc.

Components of a GIS


1-5 GIS Application classification

First, we can divide applications by customers Government

Census bureau Dept of Agriculture Dept of Defense/CIA Dept of Transportation

Education & Research Land use change research Environmental monitoring Seismological research Population research


Business Real estate development Ski resort (Happy Valley) planning Trucking company – inventory and route planning

Personal Yahoo maps GPS and map tracking system in automobiles Palm pilot Zagat’s guide, etc. Entertainment (check out GoogleEarth)

1-5 GIS Application classification (Cont.)



Information Management – data input, data editing and updating.

Data output and display Maps Spatial information queries Time series of maps (Greg Fishel shows

movement of cloud cover over the region)

GIS applications, considered by functionality



Spatial Analysis – Shortest Distance Overlay Buffer analysis Classification

Spatial modeling – has all above features. Simulations (weather) for understanding and

prediction Real-time Systems (Forest fire, military, etc., using

real time data.),


1-6 The Role of GIS within Geograhpy GIS is an effective tool that integrates human

and physical geography GIS can combine (and overlay) human and physical

data Tool v.s. science

GIS is a tool for those who use it to conduct research on other subjects

GIS is also a science, as is computer science. GISci v.s. GIS.


1-7 Synonymous Terms for GIS

Geographic Information Systems (US) Geographical Information Systems (Europe) Geomatics (Canada & Europe) GeoInformatics (Europe & Asia) Spatial Information Systems Geographic Information Science


The Market

In 2003 the US Dept of Labor listed these as the three fastest growing emerging career fields in the US (order not specified): GIS Biotechnologies Nanotechnologies

Data from GIS Monitor:


GIS Market Share - 2000

Data from GIS Monitor


GIS Market Share-2001


Geographic information systems – cont.

GIS internet resources:

Try googling “GIS”, you will find a lot of GIS related websites. Some examples:

1. Network newsgroup GIS-L (comp.infosystems.gis)

2. USGS (Geological Survey)’s brochure Geographic Information Systems (http://www.usgs.gov/research/gis/title.html)

3. News services – www.gismonitor.com, www.spatialnews.com, www.giscafe.com, www.geoplace.com.

welcome to geog 070 intro to geographic information autumn session - 2005 instructor: gregory taff

Documents

gregory taff slide

geographic information

gi gis data

formats of gi gi

world vegetation slide

satellite image slide

gi examples

study gi