Identification and evolution of peri-urban areas in the context of urban-rural integrated development: A case study of Suzhou City

Peri-urban areas are transitional urban areas with urban-rural mixed landscape and functions, and the positive change of peri-urban areas is essential to achieve the mission of urban-rural integrated development. The accurate identification of the spatial scope of peri-urban areas is a prerequisite for managing such areas, and a scientific understanding of the change of peri- urban areas can provide important references for its future development. However, due to the high complexity, dynamics, and fuzzy boundary of peri-urban areas, there is still little progress in fine- scale and quantitative identification of such areas. Under such backgroud, this study established a methodology for identifying peri-urban areas supported by remote sensing data, comprehensively considering the complexity and multi- dimensional characteristics of peri- urban areas. First, a comprehensive indicator system across socioeconomic and spatial pattern dimensions was established. Second, a measurement for peri- urban index was developed by using spatial gridding and linear weighting methods. Third, combined with the moving t-test and probability density analysis, the threshold for distinguishing peri-urban areas and nonperi- urban areas was determined. Finally, taking Suzhou City as a case, the peri-urban areas of the city in 2010, 2015, and 2018 were identified at the 1 km × 1 km scale. On this basis, the pattern of change of Suzhou's periurban areas was further discussed. It is expected that the research results can provide some references for future urbanization process of Suzhou City and other regions. The case results show that the peri-urban areas of Suzhou are spatially discontinuously distributed around the central urban district, and temporally experience a decreasing trend, especially during the period of 2015 to 2018, which indicates that the urbanization process of Suzhou City tends to be under control, and the city's rural industrialization and urban sprawl have slowed down.