| 09 Dec 2025
Mapping Three Decades of Urban Growth in China: A 30 m Annual Building Height Dataset (1990–2019)
Abstract. Long-term building height data are critical for analyzing urban morphological evolution and renewal processes, yet such datasets at fine spatial resolutions remain scarce for large geographical regions. This study proposes a framework to generate continuous annual building height maps for China at 30 m spatial resolution from 1990 to 2019, integrating multi-source remote sensing data (Landsat, Sentinel-1/2, et al.) through the eXtreme Gradient Boosting (XGBoost) model. The framework reconstructs Vertical-Vertical (VV) band, incorporates reference data derived from the Continuous Change Detection and Classification (CCDC) algorithm, and utilizes Total Variation (TV) denoising to achieve temporal consistency, while retaining inter-annual building height variations. Validation results demonstrate stable performance of the building height estimates over the past three decades, with nationwide RMSE values ranging between 5.96 and 6.69 m. Comparisons with existing datasets confirm consistency with reference building heights and their temporal evolution driven by urban development and renewal. Furthermore, our dataset shows pronounced horizontal and vertical expansion of Chinese cities between 1990 and 2019, as the total impervious surface area increases from 56,413.68 to 174,320.66 km² and overall building volume rises from 471.24 to 884.69 km³. Provincial contributions to national building volume change substantially over time, with Hebei (12.9 %), Shandong (11.4 %), and Henan (10.3 %) leading in 1990, while Shandong (10.0 %), Guangdong (8.0 %) and Jiangsu (8.0 %) are in the leading positions in 2019. The resulting annual 30 m resolution building height datasets, made openly accessible, provide a valuable foundation for cross-city comparisons, long-term three-dimensional (3D) urban morphology studies, and policy-relevant planning in fast-growing Chinese cities.
Competing interests: At least one of the (co-)authors is a member of the editorial board of Earth System Science Data.
Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
This study develops a time-series 30 m building height dataset for China by integrating multi-source remote sensing data, representing a valuable contribution to large-scale mapping of urban vertical dynamics. The dataset has clear potential for urban studies and related applications. However, several issues related to data quality, robustness, and validation—particularly for high-rise buildings and regions with limited reference data—still need to be carefully addressed to strengthen the reliability and usability of the product. The following comments are provided for the authors’ consideration.
(1) Different building height products adopt different height definitions (e.g., average height, area-weighted average height), and these definitional differences should be explicitly considered. In addition, it is worth noting that some gridded building height products may include only building information, which appears to differ from the definition adopted in this study. As a result, direct resampling and comparison across products may not be strictly comparable.
(2) The reported RMSE of 748.79 m is physically implausible and requires clarification.
(3) Please note that it is unclear whether the same reference building height data were used consistently across Fig. 10b–e. Reference heights above 20 m appear in some panels (b–d) but not in others (e), and zero-height pixels are shown for Ma’s dataset, although such values do not appear in Ma’s original released data.
(4) It is unclear whether this part of the validation is limited to buildings with heights below 45 m.
Overall, Section 4.4 requires careful re-examination.