GIS: Open Source Data

QGIS - Open Source GIS Software

QGIS (Quantum GIS) is a free open source software that runs on Linux, Unix, Mac OSX, Windows and Android operating systems.

Getting Started & Tutorials:

QGIS Tutorials and Tips
Basic and advanced tutorials for QGIS
QGIS Basics For Journalists
Tutorial from the UC Berkeley Graduate School of Journalism
QGIS Official Website
Videos and manuals for getting up to speed with QGIS

The following data sources are freely available (with a few exceptions noted) meaning they can be accessed and used by anyone.

SERVIR: Mesoamericas
A joint development initiative of NASA and USAID. Helps developing countries use information provided by Earth observing satellites and geospatial technologies for managing climate risks and land use.
-Does NOT include South America at this time
DIVA-GIS
Free geospatial data
Download country level data for any country in the world: administrative boundaries, roads, railroads, altitude, land cover, population density.
Natural Earth Data
Create custom maps at varying scales (world, region & country level)
Open Street Map
Crowdsourced streetmaps that include roads, trails, cafés, railway stations etc. for various locations around the world
Berkeley Library Geodata
Portal to open source geographic data from a variety of universities including Stanford & Harvard
OpenGeoPortal
Tufts University open data search portal
Comisión Económica para América Latina y el Caribe (CEPAL)
Gateway to all the statistical information of Latin America and the Caribbean countries (includes data for both member and non-member countries)
ACLED Regional Hub: Mexico, Central America, and the Caribbean
The Armed Conflict Location & Event Data Project (ACLED) is a disaggregated data collection, analysis, and crisis mapping project.

GEOFABRIK
Downloadable Openstreetmap data for world regions (select Region, then country).
International Monetary Fund (IMF)
Link to popular datasets as well as Datamapper, which facilitates mapping 12 comprehensive IMF datasets
The World Bank
Open data from the World Bank, including microdata & their data catalog

Social Explorer Guide
Create detailed maps using U.S. Census and other selected data.
Note: Social Explorer is NOT freely available (their free version has limited functionality)
Data.gov
Find datasets and shapefiles produced by federal agencies (not all data is GIS compatible)
Census Geography Data
TIGER files, shapefiles, and other boundary data for Census geographies
U.S. Census Geography Programs
Look for Interactive Maps, a web mapping application intended to provide users with a simple interface to view, save and print county-based demographic maps of the United States from the 2010 Census.

PolicyMap This link opens in a new window
Easy-to-use online mapping with data on demographics, real estate, health, jobs and more in communities across the US.
NOTE: PolicyMap is NOT freely available public data

National Geospatial Digital Archive
Preservation archive that serves out data or provides links to GIS data. Use the Globetrotter web interface to locate datasets.
National Historical Geographic Information System (NHGIS)
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.

The U.S. Census uses it's own geography, which ignores local boundaries like neighborhoods
It does use official government boundaries like cities, counties and states.
City and Census Tract boundaries usually change with every decennial census. Expect to see larger tracts for older census years

The U.S. Census is conducted every 10 years (decennial) and is mandated by the U.S. Constitution for the purposes of congressional apportionment.
Census data is based on a survey questionnaire so the questions asked (and therefore the available data) can change from census to census as questions are added and removed over time.
To see what a specific Census asked, take a look at this Census Bureau publication which covers 1790-2000, and the Census 2010 questionnaire.
The Census Bureau now conducts the American Community Survey, an annual statistical sampling of households. Data are reported in 1, 3 and 5 year increments.
- 1 year: Areas with population over 65,000 (most current data; smallest sample size)
- 3 year: Areas with population over 20,000 (more reliable than 1 year; larger sample size than 1 year) [this series is being phased out by the Census Bureau]
- 5 year: Covers all geographies, including very small areas (most reliable data, largest sample size)