1. SciDataCon September, 2016 Greg Yetman Kytt MacManus
Gridded Population of the World Version 4 Basic Demographic Characteristics and Data Quality Metrics
SciDataCon September, 2016
Greg Yetman
Kytt MacManus

2. 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

3. Gridded Population of the World
Gridded (raster) data product developed to provide a spatially-disaggregated 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

4. Development of GPW GPWv1 GPWv2 GPWv3 GPWv4 Publication Year
Years of Estimation
Grid Resolution
Number of Input Units (subnational geographic units)
Census variables
Population Density Grid
GPWv1
1995
1994
5 arc-minutes
19,000
Total Population
GPWv2
2000
1990, 1995
2.5 arc-minutes
127,000
GPWv3
2005
1990, 1995, 2000
~ 400,000
GPWv4
2015
2000, 2005, 2010, 2015, 2020
30 arc-seconds
(1 km)
~ 13,000,000
Total Population, Sex, Age, Urban/Rural status
1994
1995
2000
2010

5. GPWv4: Population Density

6. 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
Issues in harmonization, matching in time

7. Addition of gridded census variables
% Rural population, 2010, Panama
% Urban population, 2010, Panama

8. Data Quality Metrics: Data Context
Approximately 13.8m square km are in uninhabited, no households, and protected area categories.
About 117k square km are in the other categories
Categorizes pixels with no population estimate based on information from census documents.

9. Data Quality Metrics: Water Mask
Distinguishes between pixels that are completely water or ice and pixels that also contain land.

10. 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.

11. Using the Mean Administrative Unit Area Data
Aggregation regions larger than the input census units are highlighted

12. Population Estimation Service

13. HazPop App for iOS Free in the App Store

14. Thanks! Questions?
Greg Yetman Kytt MacManus sedac.ciesin.columbia.edu/gpw