100-m resolution Age-Stratified Population Estimation from the 2020 China Census by Township (ASPECT).

Gridded population datasets are instrumental for modeling the interactions between human and the environment at fine spatial scales. Many of these datasets are downscaled from source data of aggregated population counts by census units. Here, we introduce an Age-Stratified Population Estimation from the 2020 China Census by Township (ASPECT), estimating total population and population by age groups (0-14, 15-59, 60-64, ≥65 years old) at 100 m spatial resolution as of year 2020. ASPECT uses the updated source data from the most recent Census of year 2020, incorporating population counts and age structures from nearly all townships (n = 40,718) - the finest spatial unit for which the 2020 Census data are publicly available. Therefore, ASPECT likely provides improved accuracy in gridded population estimation when compared with datasets based on county-level data such as WorldPop. Furthermore, ASPECT presents greater spatial variations in the estimated population age structure than those from other existing datasets. These advantages of ASPECT allow for more accurate estimations on population exposure to environmental hazards and access to public services.