My demographer friend Joice Melo Vieira came up with another great tip !
!Behold!... the Global Rural-Urban Mapping Project, Version 1 (GRUMPv1)
Developed by the NASA Socioeconomic Data and Applications Center (SEDAC) operated by CIESIN, GRUMPv1 is actually a collection of three global data sets (All data sets are available for download):
- Population density and population count grids build on SEDAC’s Gridded Population of the World, Version 3 data set (GPWv3), which does not distinguish between urban and rural areas. GRUMPv1 identifies urban areas based in part on observations of lights at night collected by a series of Department of Defense meteorological satellites over several decades.
- A geo-referenced database of urban settlements with populations greater than 5,000 persons, which may be downloaded in both tabular and shapefile formats.
- An urban-rural “mask” (urban extents grid,) which identifies those areas of the Earth’s land surface that appear to be urbanized based on a combination of night-time lights, and, where there are no lights, settlement points that are buffered according to population size.
*GRUMPv1 also includes four ancillary data sets: land/geographic unit area grids, national boundaries, national identifier grids, and coastlines. All grids are provided at a resolution of 30 arc-seconds (~1km), with population estimates normalized to the years 1990, 1995, and 2000.
