Population Databases and Ultraviolet Radiation Modeling 
Darryl H. Charache 
Consortium for International Earth Science Information Network 
Socioeconomic Data and Applications Center 
USA 
This extended abstract will briefly outline two global database development activities being carried out 
at the Consortium for International Earth Science Information Network (CIESIN). 
The first project to be discussed is the acquisition and development of global gridded population 
datasets. The Center for International Research (CIR) at the United States Bureau of the Census has 
compiled a global population database (GPOPDB) comprised of three subsets: total, rural, and urban 
population counts. The rural and total population figures use rectangular grids of 20'x30 for 107 
countries worldwide. Urban population circles are estimated for regions of 25,000 people or greater. 
Censuses, surveys, maps, and gazetteers are utilized in developing these data. Censuses and surveys 
are obtained from the U.S. Bureau of the Census library or from the countries themselves. Gazetteers 
are used to coordinate information from the censuses and maps. These data, and further information 
can be found through CIESIN at the World Wide Web site URL address 
http://Www.ciesin.org/datasets/cir/gpopdb-home.html 
A more extensive and higher resolution gridded population dataset has been developed in conjunction 
with the University of California at Santa Barbara. The Global Demography Project (Tobler et 
al.,1995) involved the development of the Gridded Population of the World dataset. The estimated 
1994 population of 217 countries, subdivided into 19,032 polygons, have been assigned to 5 minute 
by 5 minute quadrilaterals. This dataset is approximately 2 orders of magnitude better in resolution 
than previously available on a global scale. The grid extends from 57 degrees S to 72 degrees N 
latitude, covering all 360 degrees of longitude. Total world population for the 19,032 units is 
estimated at 5,617,519,139. As with the CIR database , sources of information on global populations 
arise from various agencies and institutions that range from countrywide figures down to varying 
administrative levels. Final products contained in the database include piecewise continuous 
population surfaces (smoothed and unsmoothed) at 5' by 5' resolution, gridded population density 
surfaces, administrative unit name(s) for each grid cell, centroid coordinates for all 19,032 polygons 
along with area and total population of each polygon. As this project has just been completed, these 
data are not currently available on-line at CIESIN. Further information and documentation on these 
data can be requested via e-mail at ciesin.infoG ciesin.org. Another point to be noted is that 
population counts for the United States have been gridded at a 1x1 km resolution by researchers at 
CIESIN using the U.S. Bureau of the Census Public Use Microdata Sample (PUMS) datasets. This 
is made possible by the public availability of U.S. Census data; in many other countries such data is 
either proprietary or not made available by the governments. This limits the extent to which this 
gridded resolution can be applied to the rest of the world's population. Future activities at CIESIN in 
this area may involve 1 km sampling in Canada and Mexico. 
The potential uses for such gridded population data are numerous. For example, population densities 
may be used as a surrogate for examining pollutant emission patterns; for analysis of land use change; 
assessment of vulnerability to natural and technological, hazards; assessment of sea level rise impacts 
as a potential result of global warming. 
The second project discussed at the workshop presentation was the development of modeled UV dose 
levels 
latituc 
Total ‘ 
and S 
Carbc 
RANI 
Resee 
param 
for th 
estimz 
locati 
vertic: 
amou 
EROS 
Clima 
the U 
variet 
skin c 
Refe! 
Toble