Development of new open and free multi temporal global population grids at 250 m resolution
Global population grids are increasingly required and used for countless applications in analysis, modeling, and policy making. However, better and comparable global information requires improved geospatial data on population distribution and densities, in particular concerning temporal and spatial resolution and capacity for change assessment. This paper presents the development of improved global multi temporal population grids, by combining best available population estimates for 1975, 1990, 2000 and 2014, with best available assessment of the spatial extents of human settlements as inferred from Landsat satellite data for same periods. Using a dasymetric mapping approach, population is disaggregated from finest census or administrative units to built up areas. These 250 m grids represent population changes in time, having also higher spatial resolution than those previously available. The novel population grids constitute currently the de facto state of the art in terms of open global geospatial population data, potentially enabling advances in many of the fields where this information is relevant.