GPOPDB Home Page



The Global Population Database (GPOPDB) is used to map the populations of many countries around the world. The database uses a rectangular grid for mapping of 20 minutes of latitude by 30 minutes of longitude (about 2,000 square kilometers at the equator). For urban areas of more than 25,000 people, density circles are drawn to provide more detail.

IPC also prepares projections of each country's population based upon birth and death rates for single years by age and sex. These projections allow for the latest migration patterns.



The database divides the earth into Big Cells, rectangular grids of 20 minutes of latitude by 30 minutes of longitude, an area of around 2,000 square kilometers at the equator. Some country data are more detailed. The smaller Mini Cells make rectangular grids of 5 minutes of latitude by 7.5 minutes of longitude. There are 6 Big Cells in a "square" degree, and each Big Cell contains 16 Mini Cells. The location of each cell is identified by the latitude and longitude of its center point.

Population data is primarily obtained through censuses, surveys and maps from the Bureau of the Census Library or from the countries themselves. Detailed data are obtained by working from the national totals towards the first-order administrative levels; typically state, province or region. From there, data are matchedto the county or department level (second level) and then to districts or arrondissements (third level). The ideal level for the purpose of geographical distribution is the fourth level, that is, towns and villages. Data at the fourth level are not often available in a uniform coverage.

Rural Population
The rural population is distributed to a set of rectangles called Big Cells. Medium-scale (typically 1/200,000 to 1/50,000 scale) maps are used to identify individual towns and to estimate the proportion of each unit within each cell. Populations of the places falling within cells are then summed and projected.

Urban Population
Populations of urban agglomerations of 25,000 people or more are are distributed to a set of circles. City plans and large-scale maps are used to determine areas of highest population density. The entire urban area is then encompassed by circles whose radii range from 0.3 to 2.0 nautical miles. Circles are identified by the coordinates of their centers. Population estimates are made for each circle and then projected for 12 years.

Total Population and Density
The population of any urban agglomeration summed with the total rural population of the rectangular area comprises the area's total population. Density is computed using the area of the rectangle, correcting for water coverage.

Projected Population Data
Urban and rural populations are projected by extrapolating the rate of change in their ratio to total country population. Projections of the total population are based on detailed data for the three components of population change: births, deaths, and migraion.

In 1993, IPC completed work for the United States country database based on the 1990 census. This small area population database is described in more detail in an article presented by Robert Leddy ("Small Area Populations for the United States") at the 1994 Annual Meeting of Association of American Geographers. Map images are accessible via links within Leddy's article, or by accessing this image library.

For more detailed information on the Global Population Data Base, including a description on the use of these data involving Spain and Sweden, consult Chapter 4 in the ISSC "Population Data and Global Environmental Change" report. To browse the entire ISSC report, click here.



The International Data Base (IDB)

This database contains more demographic data for the countries in the world.

Metadata for related datasets can be found in the CIESIN Gateway.


For questions and requests for information about the GPOPDB contact:



International, World, Population, Projections, Urban, Rural, Georeferenced.