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