Identification of Urban Fringe Areas and Assessment of Their Landscape Ecological Risks in Xi’an, China

The urban fringe areas, situated between the urban-rural interface and critical ecological conservation zones, represent highly sensitive and rapidly evolving transitional zones within urban ecosystems, which are significantly impacted by the pressures of urban expansion. However, current academic research on their spatial identification and ecological risks remains notably limited. This study focused on Xi’an of China, utilizing multi-source data and the K-means algorithm to identify urban fringe areas during 2014–2022. Additionally, this study assessed the landscape ecological risks from three perspectives, human activities, landscape fragmentation and ecological restoration in 2022. The results demonstrate that: 1) Xi’an’s urban core and urban fringe areas significantly expanded between 2014 and 2022, growing from 145 to 471 km² and 1319 to 1884 km², respectively. The near urban core and mid-zone areas increased, while the near rural area initially decreased and then slightly recovered. 2) Over half of the urban fringe area is at medium to high ecological risk, with higher risk zones concentrated near the urban core, and slight risk areas primarily along the Weihe River and northern edges. 3) Landscape fragmentation and road network effects have become primary drivers in urban fringe areas, prompting a shift in their role from ‘future expansion area’ to ‘ecological reserve area’ to better support sustainable urban development. This study highlights the spatial complexity and ecological significance of urban fringe areas, emphasizing their critical role in urban ecological management.