The impact of gradient expansion of urban–rural construction land on landscape fragmentation in typical mountain cities, China

ABSTRACT

Hillside urbanization currently provides the most economical solution for urban expansion. However, limited attention was paid to the characteristics, processes, and patterns of gradient expansion of construction land (GEC) in mountainous regions and its impact on landscape fragmentation. This study suggests an approach to identify GEC in mountainous regions and quantify its spatial impact on the fragmentation of cultivated land and ecological land. The results are as follows: (1) GEC can be categorized as ‘unidirectional’, ‘bidirectional’, or ‘multidirectional’ expansion, influenced by the proportion of topography in different directions of the cities. The magnitude of expansion is correlated with the city's economic level. (2) GEC leads to an increasing trend of landscape fragmentation, with nearly a three-fold increase in arable land fragmentation and a two-fold increase in ecological land fragmentation within the focus areas over 20 years. (3) The impact of GEC on the fragmentation of cultivated and ecological land diminishes with distance, primarily influencing within 3 km. The results of this study provide a methodological reference for identifying key areas and characteristics of GEC, and serve as a theoretical basis for reducing landscape ecological risks in the process of mountainous urban development and promoting sustainable development.

KEYWORDS:

• Urban sprawl
• ecological land
• environmental impact
• land use
• urbanization
• SDGs

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability Statement

The land use data that support the findings of this study are available in [CNLUCC] at [10.12078/2018070201]. The DEM data that support the findings of this study are available in [NASA EOSDIS Land Processes Distributed Active Archive Center] at https://doi.org/[10.5067/MEaSUREs/SRTM/SRTMGL1.003]. The Spatial distribution data of landform types in China that support the findings of this study are openly available in ‘Resources and Environment Science and Data Center’ at https://www.resdc.cn/data.aspx?DATAID=124.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China [grant number: 42271214], National Key R&D Program of China [grant number: 2022YFC3800700], Natural Science Foundation of Gansu Province [grant number: 21JR7RA281, 21JR7RA278], the CAS’ Light of West China’ Program [grant number: 2020XBZGXBQNXZ-A], Basic Research Top Talent Plan of Lanzhou Jiaotong University [grant number: 2022JC01], the Gansu Province “Innovation Star” Project [grant number: 2023CXZX-541].