GADM, the Database of Global Administrative Areas, is a
high-resolution database
In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...
of country administrative areas, with a goal of "all countries, at all levels, at any time period." Although it is a public database, GADM has a higher
spatial resolution
In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resoluti ...
than other free databases, and also higher than commercial software such as
ArcGIS. Those sources are commonly use to complete
data analysis
Data analysis is the process of inspecting, Data cleansing, cleansing, Data transformation, transforming, and Data modeling, modeling data with the goal of discovering useful information, informing conclusions, and supporting decision-making. Da ...
with
data visualisation such as
data plots,
choropleth map
A choropleth map () is a type of statistical thematic map that uses pseudocolor, meaning color corresponding with an aggregate summary of a geographic characteristic within spatial enumeration units, such as population density or per-capita inco ...
, etc.
Format
The database is available in a few
export formats, including
shapefiles that are used in most common
GIS applications.
Marine Life Mapping & Visualisation
/ref> Files for use with the data analysis language R are also available.
License
GADM is not freely available for commercial use. The GADM project created the spatial data for many countries from spatial databases provided by national governments, NGO, and/or from maps and lists of names available on the Internet (e.g. from Wikipedia).
See also
* Natural Earth
References
{{reflist
Web mapping
Collaborative mapping
Geographical databases