How urban land expansion alters terrain in mountainous and hilly areas: An empirical study in China

Abstract

Large-scale urban land expansion in mountainous and hilly areas (UEMH) has significantly altered the terrain in many Chinese cities, leading to various environmental and urban challenges. Despite its importance, there is limited nation-scale research that reveals the amount and the spatial variations of UEMH-induced terrain alteration. This research integrates the Global Annual Urban Dynamics dataset, the Global Basic Landform Unit dataset, the TanDEM-X DEM Change Map (DCM) dataset, Baidu Points-of-Interest (POI), and other auxiliary datasets to conduct a comprehensive analysis of terrain alteration induced by UEMH in China from 2012 to 2020. The results indicate that the country-wide UEMH-induced terrain alteration reached approximately 13 billion m³, which is about 100 times the volume of Hangzhou West Lake, and terrain alteration volume in over 300 counties exceeded 10 million m³. The Southwest and Southeast regions, which are ecologically sensitive and critical, feature the greatest alteration in terms of area and volume. The most significant terrain alteration in terms of intensity is observed in the Southwest and Hengduan Mountain Area. Additionally, there are significant spatial variations in the contributions of different urban functional zones to terrain alteration. Our findings indicate that urban land expansion in mountains and hills has significantly altered terrain in some regions of China, necessitating customized urban planning strategies for better managing mountainous urban land expansion and governance policies to address the geological, ecological, and urban development challenges.

Keywords

Urban land expansion / Terrain alteration / Tandem-X DEM change map / Urban functional zones

Data availability

TanDEM-X-DEM Change Map is available on https://download.geoservice.dlr.de;

GAUD (1985–2015) dataset is available on https://figshare.com/articles/dataset/High_spatiotemporal_resolution_mapping_of_global_urban_change_from_1985_to_2015/11513178; New version of GAUD (1985–2020 or later) will be available on request; GBLU dataset is available on https://zenodo.org/records/13187969

CRediT authorship contribution statement

Zihao Zhou: Writing – review & editing, Writing – original draft, Visualization, Methodology, Formal analysis, Data curation, Conceptualization. Yimin Chen: Writing – original draft, Validation, Supervision, Resources, Methodology, Investigation, Funding acquisition.

Declaration of competing interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

The research is supported by the National Natural Science Foundation of China (Grants No. 42322110 and 42271415).

Supplementary materials

Supplementary material associated with this article can be found in the online version, at doi:10.1016/j.geosus.2025.100304.

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