TerraPop enables research, learning, and policy analysis by providing integrated spatiotemporal data describing people and their environment. The TerraPop data collection currently includes census microdata from more than 80 countries participating in IPUMS-International, aggregate census data published by an additional 80+ countries, and raster data covering land cover, land use, and climate. The TerraPop data access system (https://data.terrapop.org) enables users to combine data from datasets in different data structures into customized datasets in the structure of their choice. Integration across data structures involves transformations that hinge on boundary files linked to administrative unit codes present in census data. TerraPop has successfully developed boundary files aligned with administrative units present in census data for over 130 countries. Starting with freely available boundary data sources, including the Global Administrative Unit Layers (GAUL), Global Administrative database (GADM), and UN Second Level Administrative Boundaries (SALB), we have developed first- and second-level administrative unit boundaries matching both recent and historical census data. Boundary production has been automated to the extent possible and standardized to promote efficiency and consistency. The process entails identifying source data and information, potentially digitizing boundaries from print or image sources, aligning boundary vertices across multiple sources, and editing shapefiles to match units and codes present in census data. TerraPop also produces boundaries harmonized over time as well as units regionalized to meet minimum population thresholds to protect confidentiality when linking to microdata. The boundaries are used to perform on-the-fly transformations among area-level data, microdata, and rasters as requested through the TerraPop data access system. Users may request raster data summarized to geographic unit boundaries to create area-level data, microdata tabulated by geographic unit to create area-level data, area-level data (including tabulated microdata) distributed to grid cells to create raster data, or area-level data (including summarized raster data) attached to microdata records as contextual variables. The boundary files themselves are also available through the data access system.
|Original language||English (US)|
|State||Published - 2015|