Methods

This project builds on GPW to construct a common geo-referenced framework of urban and rural areas by combining census data with satellite data. GRUMPv1 actually comprises three data products. First, GRUMPv1 provides a higher resolution gridded population data product at 30 arc-seconds, or ~1km at the equator, for 1990, 1995, and 2000. Second, GRUMPv1’s urban extents data set delineates urban areas based on NOAA’s night-time lights data set and buffered settlement centroids (where night lights are not sufficiently bright). Third, GRUMPv1 provides a points data set of all urban areas with populations of greater than 1,000 persons, which may be downloaded in Excel, CSV, and shapefile formats. As with GPW, there is an extensive map collection depicting the data sets at country, continental, and global levels.

Methodological documentation for the Global Rural-Urban Mapping Project, Version 1 (GRUMPv1) data product is available in the following papers:

Mapping global urban and rural population distributions: Estimates of future global population distribution to 2015
The Distribution of People and the Dimension of Place: Methodologies to Improve the Global Estimation of Urban Extents
Construction of Gridded Population and Poverty Data Sets from Different Data Sources