Balancing urban expansion with a focus on ecological security: A case study of Zhaotong City, China

The conflict between socio-economic development and ecological environmental protection presents a significant challenge to achieving regional and urban sustainable development. In Zhaotong City, Yunnan Province, China, this conflict arises from the interplay between urban expansion and ecological environmental protection land, creating a fundamental tension between built-up and non-built-up ecosystems. This study focuses on investigating the spatial characteristics of expansion, constructing an ecological security pattern based on ecosystem service functions and sensitivity, and utilizing integrated models to simulate urban expansion paths and analyze their formation mechanisms. The results highlight that Zhaotong City has undergone rapid urban expansion, characterized by linear growth surrounding the central city, specifically in the east, north, and west directions. The expansion between urban areas exhibits a discontinuous dotted-star distribution, with concentrated urbanization and a distinct urban boundary observed in Zhaoyang District. In contrast, other areas experience scattered expansion, indicative of random land encroachment. Through simulation, three primary urban expansion axes are identified: the western town sprawl belt, central town development axis, and resource-rich town corridor. Ecological conflicts primarily arise in Zhaoyang District, Zhenxiong County, and Yanjin County. By combining these findings, the study analyzes the scenario pattern of urban expansion evolution in Zhaotong City, revealing a transition from the spreading spillover expansion of a single center (Zhaoyang and Ludian) during the circle expansion phase to a polycentric expansion and spreading spillover pattern centered around Zhaoyang District along three primary axial radial paths. In conclusion, this study contributes to our understanding of the challenges posed by the conflict between socio-economic development and ecological environmental protection in Zhaotong City. The findings underscore the importance of integrating ecological considerations into urban planning processes and highlight the need for sustainable development practices to achieve a harmonious coexistence between urban expansion and ecological security. The insights gained from this research offer guidance for fostering sustainable urban development in Zhaotong City and beyond.