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ENTS 120: Introduction to Geospatial Analysis

Professor John Berini - Spring 2024

City, County, State, and Other Location Based Collections

At least in the US, it is common to find open data repositories for large populations at the city, county, and state levels. These repositories pull together data from multiple sources for their area of interest. Some examples of these repositories are below. Note that sometimes open data repositories include GIS-formatted datasets and other times GIS data have their own separate repositories.

How to proceed:

  • Identify the geographic levels that might collect and share data for the location you are studying and search by name and open data (e.g. Chicago open data)
  • For US federal and state portals, first check the "US Government GIS Data - Federal and State Portals" listing below, then
  • Search online for the areas of interest, one at a time, (e.g, Chicago, Cook County, Illinois, etc.) by name with phrases like "open data," "data portal," "spatial data," "gis data," "geospatial data." 

U.S. Federal and State Spatial Data Portals

Examples of Portals from Cities, Counties, States, and the Nation

Example: Relevant portals if you want data about LA

Local (City, County, Etc.) Agencies that Share Data

Open data portals get their data from government agencies and organizations within their geographic area. Sometimes those portals are comprehensive and other times they only scratch the surface of what is available. Often the originating agencies offer more data than what they share with the larger portals. It's a good idea to identify the agencies that collect the kind of data you're interested in and look for the data they share. Some examples are below to give you an idea.