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Maps and Geospatial Resources: GIS

GIS Tools and Resources

Geographic Information Systems (GIS)

Geospatial data are electronic data that include some kind of location information, which could be latitude longitude coordinates, an address, a zip code or a county. These data are generally used in Geographic Information Systems (GIS), cartography, and remote sensing software packages. Data can be obtained from central clearinghouses (listed below), local organizations, and/or generated by researchers in the field.

From the interesting GIS Lounge portal: There is a distinct difference between GIS and Geospatial data, in that GIS refers more narrowly to the traditional definition of using layers of geographic data to produce spatial analysis and derivative maps.  Geospatial is more broadly used to refer to all technologies and applications of geographic data.  For example, popular social media sites such as Foursquare and Facebook use “check-ins” that allow their users the ability to geographically tag their statuses.  While those applications are considered to be geospatial, they don’t fall underneath the stricter definition of what makes up a geographic information system.



    The National Historical Geographic Information System (NHGIS) provides population, housing, agricultural, and economic data, along with GIS-compatible boundary files, for geographic units in the United States from 1790 to the present.
  • GEO-DATA Explorer (GEODE)
    Use GEODE to access, view, and download information from geo-spatial databases containing a broad spectrum of data produced by the USGS and other governmental agencies.
  • Geographic Information Systems (GIS)
    Basic information about GIS from US Geological Survey (USGS).
  • FGDC Geospatial Metadata
    Develops procedures and assist in the implementation of a distributed discovery mechanism for national digital geospatial data. Geospatial metadata are critical to data discovery and serves as the fuel for the NSDI Clearinghouse.
  • Harvard Tutorial on GIS
    Three flash videos demonstrating GIS capabilities.
  • Portal to Locate GIS Data
    Stanford University guide to locating GIS data.


  • Illinois Geospatial Data Clearinghouse
    Access Illinois GIS data sets and documentation (metadata) for ArcIMS Interactive Map Services, USGS digital topographic maps, aerial photography, orthoimagery, orthophotography, geology, land use, natural resources, and infrastructure. Illinois data sets and map data layers are available for download free of charge.
  • Illinois GIS Data Providers
    A large selection of agencies and bodies providing local data.
  • Illinois Free GIS Data
    Free Geographic Information System (GIS) Data: This service is for GIS professionals to accompany our imagery offerings. You must have the appropriate GIS software and experience in order to utilize this data. We recommend ESRI ArcView to utilize data with different formats and projections.
  • Great Lakes Information Network (GLIN) GIS Clearinghouse
    The mission of GLIN Maps and GIS is to provide a centralized location to discover, publish, and acquire geospatial data for areas within the Great Lakes region. The site has four major components: 1) a portal for viewing and exploring the Great Lakes and associated data layers, 2) a data portal (GLIN GIS) through which GIS and geospatial data for the Great Lakes can be published and acquired, 3) a gallery of downloadable images depicting Great Lakes geophysical data, and 4) a collection of links and tools intended to connect users to additional resources relating to Great Lakes datasets.
  • Illinois GIS Association Board
    ILGISA brings together the GIS community of the State of Illinois through biannual conferences and the publication of Illinois GIS Notes.
  • DoubleMap bus locator ... showing current locations of public buses.
  • journal article containing a locally developed map of parakeet distributions (Minor, E.S., Appelt, C.W., Grabiner, S., Ward, L., Moreno, A., Pruett-Jones, S. Distribution of exotic monk parakeets across an urban landscape. Urban Ecosystems, Volume 15, Issue 4, November 2012, Pages 979-991.)


    Some Helpful Tools:


Scribble Maps

Scribble Maps allows you to create quick maps with pins, highlighting, and annotations. It also allows you to use lines to calculate distances. This sample map that highlights a few locations took only a few minutes to create ... and can be inserted into web pages, blogs, or paper documents.

Zee Maps

Zee Maps allows you to create quick maps with pins, highlighting, and annotations. It allows you to highlight specific states, counties, and zip code areas.


QGIS -- a free (open source) software product providing web-based GIS capabilities.  A tool that requires a less intensive learning curve than the more powerful ESRI suite of GIS software. This tool is powerful, if used to its fullest capability, but it does not have the large support structure of advanced scripts and applications or the same size cooperative user base as the commercial ESRI product.  



GIS Vocabulary

The following are simplistic descriptions to help a beginner understand some of the key terms and concepts used in GIS:

  • Raster image - a shape file (think of a park coded as a square area).  Such a shape entity can not be easily manipulated and analyzed.
  • Vector image - object composed of points with both spatial and value descriptors (This complex object can be manipulated and analyzed.)
  • Georeferencing - describing an object's location within a spatial grid (for example, longitude and lattitude). Such objects can be overlayed with other objects (as layers) with a similar frame of reference.  Imagine overlaying streets, bus routes, and parking lots.
  • Layers - data sets that can be added to other data sets and overlayed onto a spreadsheet and/or map grid. Imagine railroad tracks, rivers, gas stations.
  • Datum - a standard for cailbrating spacial relationships and references at a given time.  Imagine the exact location of earth's continents on Jan 1, 1995.  These spacial objects move in relation to each other, so you must be careful to use similar calibrations when overlaying data sets. 
  • Projections - various ways to represent a round object on flat surfaces or maps. Different projections provide skewed approximations and can result in significant distortions in relative sizes from North to South, top to bottom, etc.
  • Scripts - programs written to perform various manipulations on data sets. Imagine defining vegetation types from the color of reflected radiation patterns.

For a more complete set of definitions see the esri GIS Dictionary.

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