GIS Data & Resources

A guide for finding GIS data and a listing of selected GIS data sources.

Selected Map & GIS Data Sources

United States Geological Survey (USGS) National Map Viewer: The USGS National Map Viewer allows users to explore and download vector geospatial data, mainly for the United States.

USGS EarthExplorer: The USGS Earth Explorer is a USGS tool for querying and ordering raster geospatial data including satellite images, aerial photographs, and cartographic products. Log in as a guest or as a registered user. Registered users have access to more features than guests do. If you plan on using Earth Explorer frequently, you may wish to register.

OpenGeoportal: A site for discovery of geospatial data from multiple sources developed and maintained by Tufts University.

EarthWorks: A geospatial data discovery site with data contributed from a number of leading universities as well as state and local governments. The project is overseen by Stanford.

California Open Data Portal: A statewide data portal sponsored by the Government Operations Agency to host open data from across California government agencies.

Census Bureau: A principal agency of the U.S. Federal Statistical System, responsible for producing data about the American people and economy.

Digital Coast: A National Oceanic and Atmospheric Administration (NOAA)-sponsored website focused on helping communities address coastal issues. Provides coastal data, training, and information. Content comes from many sources, all of which are vetted by NOAA.

Diva GIS: Provides free downloads of shapefiles for basic data including administrative boundaries, inland water, roads, and railroads. Downloads available by country.

Esri Open Data: Has more than 67,310 open data set from more than 4,000 organizations worldwide. Managed by the largest commercial GIS organization in the world. Download formats are in spreadsheet, KML, shapefile.

Geolode: A collaborative catalog of open geodata websites around the world.

GeoPlatform.gov: Aggregates, indexes, links, and organizes web resources of all kinds into a managed collection of curated objects called the GeoPlatform Portfolio.

Geospatial Data Gateway (NRCS - Natural Resources Conservation Service): Define a region and download recent imagery, census, and climate data (among others). Includes the National Agricultural Imagery Program Mosaic imagery.

Marine Cadastre: An integrated marine information system that provides data, tools, and technical support for ocean and Great Lakes planning. Developed through a partnership between the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) Office for Coastal Management and the U.S. Department of the Interior's Bureau of Ocean Energy Management (BOEM).

NASA's Socioeconomic Data and Applications Center (SEDAC): Retrieve global socioeconomic data from 15 different themes including agriculture, climate, conservation, governance, hazards, health, infrastructure, land use, marine and coastal, population, poverty, remote sensing, sustainability, and urban and water.

National MapViewer: Allows visualization and download of topographic base map data and other data themes including: Elevation, Orthoimagery, Land Cover, Hydrography, Geographic Names, Boundaries, Transportation, and Structures.

Natural Earth: a public domain map dataset available at 1:10m, 1:50m, and 1:110 million scales. It includes both cultural and physical layers.

GIS Literature

ESRI's GIS Bibliography covers the literature of geographic information systems, science, and technology, indexing journals, conference proceedings, books, and reports from the origins of GIS to the present.

Finding GIS Data

The below guidance is from UC Davis Library's Maps, Mapping, and GIS subject guide, authored by Michele Tobias, David Michalski, and Dawn Collings. Additional tips are resources are included on this GIS Data library guide from Syracuse University.

Finding existing GIS data is a common but often difficult task. Sometimes the data you would like is simply not available, but other times it's just difficult to find. Here are some strategies for finding data.

Search Engines

Searching for data online is going to require a search engine. Many search engines have advanced options that can help narrow down a search or restrict the results. For example, Google has menus for Settings and Tools, as well as searches targeted to specific results like images.

Search Terms

Keep your search terms broad. Also, try synonyms for terms you are interested in. For example, if you were looking for a shapefile of beaches in California, you might try separate searches for "beach shapefile" or "coast shapefile". Also, try synonyms for the data type. "GIS", "map", "geospatial", and "shapefile" might find different but relevant results.

Think about how data might be developed or what kinds of layers would go into your analysis rather than terms that define your final product. For example, you might be interested in identifying areas considered a "food desert" but you might need to look for layers for "census data" and "grocery store locations".

Results

Search results for geospatial data often fall into one of three categories.

  1. Good: blog posts explaining where to find data, why there is a lack of data, or what tools could be of use for your field.
  2. Better: Question board responses on sites like Stack Exchange. These can be a treasure trove of solutions, but also frustrating if your question was posted a while ago and has no answers.
  3. Best: Sites like repositories with links to download the data you are looking for. Don't forget to check for metadata so you have some provenance for your data.

Data Repositories

Data repositories are places that store data. Many public repositories are themed by subject or by the entity that produces the data. For example, many California counties, the State of California, and the federal government have their own repositories for GIS data, including repositories for specific agencies. Data Basin is an example of a subject-specific repository that focuses on data for environmental stewardship.

Academic Publications

Researchers in your field may be using datasets that are useful for your research. Read the methods section and citations list to look for sources of datasets and links to how to access the data.

Asking for help

For SMC community members, please contact a librarian if you need assistance locating publicly available GIS datasets. If the data you need is from a particular place, such as a county or conservation organization, you may be able to contact the organization's GIS, data, or IT staff to ask about the availability of data. Additionally, posting in online forums, websites, or social media using keywords that describe the data you need and hashtags to get a broader audience can be fruitful.

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.