AGPC: An Annual 500 m Gridded Population (1990–2020) for China Incorporating 3D Building Volume Dynamics

At the county level, AGPC shows strong agreement with census data, with correlation coefficients <i>R</i> greater than 0.89 and relative RMSE values below 1 % on the independent validation sets for the baseline years 2010 and 2020. At finer scales, grid-level population estimates aggregated to the township level exhibit high consistency with independent census data with <i>R</i> greater than 0.90, indicating satisfactory capability in capturing finer-scale spatial heterogeneity in population distribution.

Multi-temporal validation at the city level for seven time points between 1990 and 2020 yields correlation coefficients ranging from 0.79 to 0.99, indicating stable temporal performance. Comparisons with existing global and regional population datasets show that AGPC better captures population patterns in high-density and vertically developed urban areas, avoiding the density saturation effects commonly observed in 2D products.</p><p dir="ltr">Version 5 incorporates refined administrative population constraints to strengthen the temporal continuity of the annual estimates.

The data files are organized into two folders. “AGPC_Annual_City_Constrained_1990_2020” contains 31 annual gridded population layers for 1990–2020, with the estimates for each year constrained to the corresponding city-level population totals. “AGPC_County_Constrained_2010_2020” contains the 2010 and 2020 population layers constrained to county-level totals. For the earlier benchmark years, the city-level population constraints for 1990 and 2000 were derived from China’s Fourth and Fifth National Population Censuses, respectively.</p><p dir="ltr">A demo of AGPC data visualization is available at the following link: code.earthengine.google.com/af3692f315897c08fb8625b14bc0e773</p>