Accuracy Assessment of Global Gridded Population Datasets at Approximately 1-km2 Grid Level
摘要
Global gridded population (GGP) datasets provide estimates of a population within a grid and are used across various disciplines. However, their accuracy, particularly at the spatially fine grid-cell level, is poorly understood. Therefore, in this study, we empirically evaluated the accuracy of four common GGP datasets (GHS-POP, GPWv4, LandScan, and WorldPop) for Japan and several EU countries (France, Germany, Italy, and Sweden) at approximately 1-km2 resolution. In addition, we examined an ensemble of GGPs and smart selection of GGPs using a random forest model. The results indicated that (1) GHS-POP achieved at least second-best accuracy in most cases for both Japan and the EU; (2) simple averaging of GHS-POP, GPWv4, and WorldPop may improve the accuracy, although the sole use of GHS-POP was generally associated with better accuracy; and (3) dataset selection using a random forest model with the GGP datasets and infrastructure as explanatory variables did not improve accuracy outside the country for which the model was trained.