Urban, Rural and Total Population for the Year 2000 for the World Water Development Report II

Global population fields were constructed for the year using country-level
demographic statistics from the World Resources Institute (WRI) Earth Trends
database (http://earthtrends.wri.org/). The urban and rural population data
sets were developed by spatially distributing the WRI 2000 country level
population data among DMSP-OLS nighttime stable-lights imagery (Elvidge 1997a)
and ESRI Digital Chart of the World populated places points (ESRI 1993).
Country-level urban population was evenly distributed among the DMSP-OLS city
lights data set at 1-kilometer grid cell resolution with detectable lights in
at least 10 per cent of the cloud free observations (Elvidge 1997b). Where
available, the spatial extents of major city locations with known demographic
data (Tobler 1995) were superimposed in the DMSP-OLS city lights data set to
enhance the accuracy of the urban population distribution. Rural population
was spatially distributed equally among the DCW populated places points falling
outside of the DMSP-OLS city lights extent. Total population is simply the sum
of urban and rural population data sets.