The Center for International Earth Science Information Network (CIESIN) is a center within the Earth Institute at Columbia University. CIESIN works at the intersection of the social, natural, and information sciences, and specializes in on-line data and information management, spatial data integration and training, and interdisciplinary research related to human interactions in the environment.

Enhanced Population Mapping Tools Deliver Customized Demographic Estimates

A screen capture from the updated Population Estimator mapping tool for an area along the coast of Wilmington, North Carolina, affected by Hurricane Florence in fall 2018, displays estimates of the distribution of males and females by 5-year age group. The tool accesses data from the Gridded Population of the World version 4 (GPWv4.10) data collection via the Population Estimation Service (PESv3).

The Population Estimation Service (PES) and associated Population Estimator mapping tool have recently been updated to provide users with the ability to visualize changes in total population over multiple decades together with basic demographic characteristics (age and sex) in the year 2010, for a user-defined geographic region. Version 3 of the Population Estimator enables users to draw a circle or polygon on a world map, which then produces a graph of estimated population for the years 2000, 2005, 2010, and 2015, and a projection to the year 2020. The Population Estimator also provides a “population pyramid” for the year 2010, with estimated population counts by five-year age groups for males and females. Users may save the graphs in selected image formats and download the tabular data for further analysis.

These detailed demographic estimates may be highly useful to those interested in assessing how different areas of the world vary in terms of their population growth between 2000 and 2020, and in comparing the relative shape and structure of their population pyramids. The data may be used to estimate important demographic characteristics such as the sex ratio, median age, dependency ratios, and the number of women of child-bearing age. Estimated totals for specific age  groups (children under five or the elderly) may be useful as indicators of potential vulnerability to natural, technological, or human health hazards or of the type and level of specific social or health services needed in an area. However, it should be noted that in many parts of the world, censuses have been infrequent, and detailed demographic data at subnational levels are not always available; therefore, population and age-sex data for small subnational areas should be used with caution and the documentation should be consulted.

Behind the scenes, the PESv3 draws on the latest version of the Gridded Population of the World data collection (GPWv4.10), which is based on the most current national census data available. Through open web service protocols, any client developer can send queries to the PES to obtain customized estimates for a specified circle or polygon. Links to the service descriptions are available online. Further information is available through SEDAC User Services. PESv3 and the Population Estimator are supported by the NASA Socioeconomic Data and Applications Center (SEDAC), operated by CIESIN as part of the NASA Earth Observing System Data and Information System (EOSDIS).