LandScan Global 2023 (Silver Edition): Global Gridded Population Estimates

Abstract

For a quarter of a century, the LandScan Global (LSG) project has annually released, a global, high resolution gridded population dataset representing the ambient or unwarned population at a 30 arc-second resolution. LSG supports a range of applications such as emergency management, disaster response, and human health and security for understanding populations at risk. The 2023 release of LSG, the LandScan Silver Edition, represents a major methodological leap forward while also leveraging previous knowledge – the previous year was the baseline for the current annual update carrying forward valuable knowledge of the built environment for the past quarter century - to train the machine learning models. In comparison to annual releases over the past 24 years, multiple advancements were made to different aspects of the methodology to achieve reproducibility, transparency, and consistent global propagation of solutions to modeling or population distribution issues identified during the review process. These novel changes include incorporation of the latest available Geo-spatial inputs across the globe, machine learning models instead of manual modifications, population feature importance analysis, open source solutions versus use of proprietary software, generation of multiple global versions, analytic validations, and human in the loop revisions to produce the final version. Additionally, algorithms - such as Anomaly Detection -were introduced to quickly identify areas of focus in development of a new and robust systematic review. Significant changes in modeled population distributions are observed between the 2022 and 2023 releases, largely attributable to improvements in data and methods and discussed thoroughly within this report. In summation, the LandScan Silver Edition leverages the best of the past quarter century of LSG legacy knowledge and continues a tradition of applying cutting-edge enhancements to serve as a new benchmark for accurate, actionable gridded population data.