Lecture 1 - Introduction to GIS

General note: ask questions at any time…

Logistics

Options for file storage this semester (set up your preferred method by Wednesday)

1. USB key drive/thumb drive/flash memory
2. Oncourse (see KB and course FAQ)

Working on lab exercises, finding labs on campus with ArcGIS

• ArcGIS is available in all campus STC labs
• Student Building and SPEA labs have restricted access (building closes at night)
• Information Commons available 24/7

What is GIS?

Geographic Information Systems (GIS) vs. Geographic Information Science (GISc)

Geographic Information Systems

• Spatial data collection
• Spatial data storage (library/archive)
• Spatial data querying and retrieval
• Spatial data reporting/cartography
• Spatial data manipulation/analysis

GIS as a tool for archiving data
Example: INDOT and road construction

Indiana Department of Transportation - NW Indiana Driving Conditions

GIS Atlas for Indiana

GIS as a tool for data retrieval

Monroe County parcel/property database (plug-in required)

Google Maps - Google Earth (download required)

Google Maps Mashups

Los Angeles Homicide Map (temporarily down as of Aug 13, 2009)

GMaps Pedometer

Swiss Trains

GIS as a tool for integration and data analysis
Example: Providing a spatial representation of features allows data to be integrated (overplayed) allowing for relationships to be explored

Planning for Rail Routes on Staten Island

OakMapper Website - Where is Sudden Oak Death occurring in California and why?

GIS Basic Issues and Concepts

These are important threads to keep in mind throughout the course

• Spatial Data Representation
  • Representing real world in a digital spatial database always involves some error and misrepresentation
  • Goal is to minimize this misrepresentation via decisions of the GIS analyst
    Examples: Representing cities as points or areas, representing roads as lines or areas
  • GIS analyst must make decisions about how to represent real world features
  • GIS analyst must choose specific method to integrate data which affects the results of the integration
• Scale issues and GIS
  • Data are collected at a certain scale and represented at a certain scale
  • Example: Representation of an interstate highway on a map of the City of Indianapolis or a US road highway map
• GIS and Error
  • This course will emphasize error issues in GIS
  • Spatial and aspatial error
  • All spatial data have error, the question is, is the amount of error in your GIS acceptable for the purposes of your GIS?
  • Slight spatial error on road locations in a GIS not too big a deal if the purpose of the GIS is to produce coarse scale highway maps (e.g. US)
  • But slight error for road locations in a GIS can be a huge issue for a civil engineer
  • If you understand error issues then you understand the underlying issues with spatial data representation. Nothing is worse than a blind clicking of buttons without knowing what is actually happening to produce the output...

Purpose of a GIS

Important to understand the purpose of the implementation of your GIS. The purpose behind the design and development of GIS data affects the representation of the data.

GIS databases constructed for a specific purpose vs. GIS databases constructed for general purpose

GIS and time

Snap shot vs. dynamic representation
Keep most up to date status or do you track changes over time?

Spatial scale vs. temporal scale

Spatial resolution
Spatial extent

Temporal resolution
Temporal extent

The resolution and extent that you choose for your GIS depends on the purpose of your GIS and any research questions behind the motivation for your GIS

Course context

• What you’ll be able to do at the end of this class:
• Construct digital spatial databases
• Use basic spatial analytical tools
• Convert data between different spatial representations
• Limited coverage of cartographic principles in this class

G237 – introductory course with more emphasis on cartography and less emphasis on analysis
G438/G539 – Advanced GIS - Extends to analytical techniques not covered in this class

Course Software Issues

This course will use ArcGIS 9.3.1 as the main GIS application, there are other GIS packages

ArcGIS is organized into the following modules, the first computer-based lab exercise will provide an overview of these:

• ArcMap
• ArcToolbox
• ArcCatalog