To provide estimates of population count for the years 2000, 2005, 2010, 2015, and 2020, consistent with national censuses and population registers with respect to relative spatial distribution, but adjusted to match United Nations country totals.

To provide back-cast population count estimates at 30 arc-second (~1 km) resolution.

To provide back-cast population density estimates at 30 arc-second (~1 km) resolution.

To provide gridded demographic data, including characteristics of age, race, ethnicity, and housing, for the United States and Puerto Rico for data integration.

To assess likely future areas of urban expansion up to the year 2030.

To provide estimates of net-migration (in-migration minus out-migration) per one-kilometer grid cell on a decadal basis for the 1970s, 1980s, and 1990s.

To provide gridded demographic data, including characteristics of income, education, and housing, for metropolitan statistical areas at a finer resolution than is available in the 30 arc-second grids used for the United States as a whole.

To provide gridded demographic data, including characteristics of income, education, and housing, for the United States for data integration.

To provide gridded demographic data, including characteristics of age, race, ethnicity, and housing, for metropolitan statistical areas at a finer resolution than is available in the 30 arc-second grids used for the United States as a whole.

To provide gridded demographic data, including characteristics of age, race, ethnicity, and housing, for the United States.

To provide a time series of raster population data for ntegration with other data sets.

To provide a raster representation of urban areas (or urban mask) for use with GRUMP population grids or other data sets.

To provide land area data for use with GRUMPv1 population and urban data as well as a quantitative measure of resolution of the input spatial units for GRUMPv1.

To provide a time series of raster population density data for data integration.

To permit the summation of population values by country/territory and, in combination with other data layers, the summation of population values by irregular areas represented in the other data layers and country/territory.

To provide gridded demographic data, including characteristics of age, race, ethnicity, and housing, for the United States and Puerto Rico for data integration.

To provide gridded demographic data, including characteristics of income, education, and housing, for metropolitan statistical areas at a finer resolution than is available in the 30 arc-second grids used for the United States as a whole.

To provide gridded demographic data, including characteristics of income, education, and housing, for the United States and Puerto Rico for data integration.

To provide gridded demographic data, including characteristics of age, race, ethnicity, and housing, for metropolitan statistical areas at a finer resolution than is available in the 30 arc-second grids used for the United States as a whole.

To preserve access to the original population data used by the Millennium Ecosystem Assessment (MA) and other related research.