Transcript Presentation

Gridded Population of the World
Version 4
Basic Demographic Characteristics
and Data Quality Metrics
SciDataCon September, 2016
Greg Yetman
Kytt MacManus
Socioeconomic Data & Applications Center (SEDAC)
• Focus on human dimensions of
environmental change
• Integration of social and earth science
data, especially with remote sensing
• Direct support to scientists, applied and
operational users, decision makers, and
policy communities
2
Gridded Population of the World
• Gridded (raster) data product developed to provide a spatiallydisaggregated population surface that is compatible with data sets from
social, economic, and Earth science fields.
• Census population data are transformed from their native spatial units to a
global grid of quadrilateral latitude-longitude cells (Balk et al. 2010)
• Free and openly available
GPW version 3, 2000 population density
Transforming census units to a grid
Development of GPW
Years of
Publication
Estimation
Year
GPWv1
GPWv2
1995
2000
1994
1990, 1995
Number of
Input Units
Grid Resolution (subnational
geographic
units)
5 arc-minutes
2.5 arc-minutes
19,000
127,000
Census
variables
Population Density Grid
Total
Population
1994
Total
Population
1995
GPWv3
2005
1990, 1995,
2000
2.5 arc-minutes
~ 400,000
Total
Population
2000
GPWv4
2015
2000, 2005,
2010, 2015,
2020
30 arc-seconds
(1 km)
~ 13,000,000
Total
Population,
Sex, Age,
Urban/Rural
status
2010
GPWv4: Population Density
Additional Demographic
Characteristics
• Sex ratio
• Age: 5-year age groups
– Some exceptions where only three age categories
may be available (child/youth, adult, elderly)
– Select countries have single-year breakdowns
• Urban/Rural status—as designated by national
census or mapping organizations
Addition of gridded census variables
% Rural population, 2010, Panama
% Urban population, 2010, Panama
Data Quality Metrics: Data Context
Categorizes pixels with no population estimate based on information from
census documents.
Data Quality Metrics: Water Mask
Distinguishes between pixels that are completely water or ice and
pixels that also contain land.
Data Quality Metrics
Mean Administrative Unit Areas
Area of the input census unit from which each pixel is derived. Where
multiple units cover a pixel, the mean of the input units is used.
Using the Mean Administrative Unit Area Data
Population Estimation Service
HazPop App for iOS
Free in the App Store
Thanks! Questions?
Greg Yetman
[email protected]
Kytt MacManus
[email protected]
sedac.ciesin.columbia.edu/gpw