Geographical Information Systems (GIS)
Introduction
What is GIS?
Geographical Information Systems are interactive maps combined with databases. This allows questions such as "where should I open a business?" or "how many people would be affected by a chemical spill in this creek?" or "how many people within 21 miles of Lexington, Kentucky speak Spanish?"
GIS can usually handle several layers of data, to answer more complicated questions like "if there is a spill in this creek, will we need to announce it in Spanish, because the people downstream are not fluent in English?"
Look at some uses of GIS at ESRI.
Problems obtaining good data from GIS sites
- Can data be downloaded into your GIS?
- Sometimes you can just look at a picture of a map. For instance, the TerraServer displays satellite photos, but it would be more useful if the photos were geographically referenced using points such as latitude & longitude, making it possible to add a satellite photo to a GIS project in the proper spot.
- Is the data in a useable format? That will depend on your GIS.
- If you are using products from one GIS company, you will not necessarily be able to read files from a different GIS company. Remember when WordPerfect could not read Microsoft Word files? With GIS data, there is no agreed-on lower format like ASCII for text.
- How much will the data need to be "massaged"? Will you need to fix things in a spreadsheet/database?
- Some data sources will have more data than you want, and you will need to remove the excess. Or there will be less, and you will have to add some additional. Perhaps they have all the counties and cities, but the county seat will not be indentified. You would need to add to the data (or find it from another source).
- Did you get the data needed? Sometimes after download, fields are labeled cryptically.
- The people who are used to dealing with large data sets will probably have abbreviated terms, to save space in the database. Sometimes it is hard to know that in demographic data "FHH" means "female head of household."
- Will you be able to add other data? Are their good "hooks" in the existing files?
- The power of GIS is its ability to link data from different places. But if you have a database of retail establishments by county and a map of an area by city names, you can't necessarily view them together. You would need to have a common field in the two sets of data in order to join them.
- Do they use the referencing schemes that you need?
- Not everything is going to be in latitude and longitude. There are several other locational systems in very common use. Often, if you need to find two maps to superimpose, one will be in UTM (with values in the thousands of meters), the other in degrees (from -180 degrees to 180 degrees), so the two maps won't "fit" together. Not to mention that inside a locational system, various standards (e.g., the 1927 standard or the 1983 standard) might be used, and thus locations are off several meters or miles.
- Data Download Sites from NCSU Libraries GIS Data Services.
- Geospatial and Statistical Data Center at Univ. of Virginia
- Alexandria Digital Library Project at the University of California Santa Barbara
- Environmental Systems Research Institute Canada
- Texas Natural Resources Information System
- State and County QuickFacts from the U.S. Census Bureau
- Census State Data Centers
- Census 2000 TIGER/Line Data
- GIS users can download Census 2000 TIGER/Line Data in shapefile format for an area of interest. Users can choose multiple data layers for a single county or a single data layer for multiple counties and analyze them using GIS software such as ArcGIS and ArcExplorer-Java Edition.
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- Demographic Data Viewer 3.0: Java-based on-the-fly mapping from CIESIN/SEDAC.
- Maps from the Research Guide for Maps, University of Kentucky Libraries.
- GISLinx - more for the professional; includes job listings, etc. (Four stars from Argus Clearinghouse)
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GIS from Yahoo - Other Sites
- Census Watch, ESRI site with access to information on Census-related data resources, redistricting, online GIS mapping, education and training, as well as news and articles.
- GeoCommunity, source for GIS data, software, news and discussion.
- Geospatial and Statistical Data Center, at the University of Virginia Library.
- GeoPlace.com
- GIS Related Information Servers, from the U.S. Geological Survey.
- GIS and Geography Related Websites, from Goddard Splace Flight Center.
- Infomine Maps & GIS Search, University of California's index to scholarly internet resource collections.
- Kentucky Division of Geographic Information
- MapInfo, with downloadable demonstration software.
- Spatial Data Transfer Standard (SDTS) Information Site
- TopoZone, by Map a la Carte, Inc.
Kentucky Sites
ESRI software available for the UK Community
Kentucky Geological Survey Geospatial Data Library
Includes county maps, DEMs, DLGs, and DOQQs.
Kentucky Division of Geographic Information
Provides access to geospatial data and standards.
Kentucky Geospatial Board
Assists state and local jurisdictions in developing, deploying, and leveraging geographic information resources and geographic information systems technology for the purpose of improving public administration. The KGB also seeks to insure maximum use of geographic information by minimizing the redundancy of information and resources.
Kentucky Atlas
Atlas and Gazetteer.
GIS Centers-- Academic
- Maps & GIS resources, from Infomine, University of California Riverside.
Government GIS resources on the Web
Guides
Standards
- Federal Geographic Data Committee (FGDC) Content Standard for Digital Geospatial Metadata
University Consortium for GIS (UCGIS), an organization to which UK belongs (contact Francis Harvey for more information).
ESRI information