Beyond built-up land: Mapping complete settlement footprint in China from 1990 to 2020 with Landsat imagery

Abstract

Accurate mapping of human settlements is vital for understanding urbanization, human-environment interactions, and sustainable development. Existing medium-resolution products often underestimate the real spatial extent of settlements by focusing solely on built-up cores. Here, we present the China Settlement Footprint 1990–2020 (CSF30) dataset, a nationwide product depicting complete human settlement footprints from Landsat imagery at five-year intervals. CSF30 was generated using an Entity-Based Image Analysis framework integrated with a deep learning architecture. To ensure spatio-temporal generalizability and boundary accuracy, the model was trained via a two-stage strategy utilizing a built-up area dataset and a newly annotated settlement footprint dataset. Comprehensive validation demonstrates that CSF30 achieves a mean F1-score of 0.91 across the 30-year period, showing distinct advantages in representing rural and peri-urban areas compared to existing products. CSF30 provides a critical, high-quality baseline for diverse applications, including investigating settlement trajectories, assessing ecological and environmental impacts, and monitoring progress toward the Sustainable Development Goals (SDGs).