Teaching with Open Source Software

Richard E. PlantDepartments of Biological and Agricultural Engineering

and Plant SciencesUniversity of CaliforniaDavis, CA

Definition of a geographic information system:

“a computer system capable pf assembling, storing, manipulating, and displaying geographically referenced information, i.e., data identified according to their locations.”(Lo and Yeung, Concepts and Techniques in Geographic Information Systems 2007, p. 2)

Spatial Data

Georeferenced data consists of two components: Aspatial component: the phenomenon

or phenomena being recordedThis is called attribute data

Spatial component: the location and spatial properties of the phenomenonThis is called geographic data

The components of a GIS

Applications of GIS

Display of thematic maps resulting from the analysis of geographic processes

Example: change detection in a California oak woodland

Aerial Photos

1952 1993

Georegistered

1952 1993

Map algebra result

ArcGIS: The “Big Daddy”

Quantum GIS: an open source alternative

Course labs

QGIS Version

Graduate seminar (run by TAs)

Each week One student presents the week’s lab All students work the lab Students turn in comments and

criticisms

Problems

Buggy software Not ready for prime time

Necessary to carry out many operations in R

Version inconsistency

Benefits

Anticipated I got a constructive criticism of the labs The students learned an ArcGIS alternative

Unanticipated Some of the students really got into it

Enthusiasm for subject Student involvement in program development

Contact with developers Sense of ownership and participation Sense of shared challenge among the

students Continuation of seminar into other open source

programs

Thank You!