D1 through D3 DESCRIPTION:
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 bservations
(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.
DOWNLOADABLE FILES:
(D1)
Urban_pop_2000.asc = Urban population in people per grid cell (30-min) for the
year 2000. Primary source: Vorosmarty et al (2000).
(D2)
Rural_pop_2000.asc = Rrban population in people per
grid cell (30-min) for the year 2000. Primary source: Vorosmarty
et al (2000).
(D3)
Total_pop_2000.asc = Total population in people per grid cell (30-min) for the
year 2000. Primary source: Vorosmarty et al (2000).
REFERENCES:
Elvidge, C., K.
Baugh, E. Kihn, H. Kroehl,
Elvidge, C., K. Baugh, E. Kihn, H. Kroehl, E. Davis, C. Davis.
1997b. Relation
between satellite observed visible-near infrared emissions, population,
economic activity and electric power consumption. Int. J. of Remote Sensing, Vol. 18, No. 6, pp 1373-1379.
ESRI,
The Digital Chart of the World. 1993.
Environmental Research Systems Institute, Inc.
Tobler, W., U. Deichman, J. Gottsegen, and K. Maloy, 1995. The Global Demography Project, Technical Report TR-95-6, NCGIA,
ADDITIONAL LINK:
CIESIN/COLUMBIA UNIVERSITY Population
Data