Quantifying the spatial arrangement of underutilized land in a rapidly urbanized rust belt city: The case of Changchun City

Regenerating underutilized lands in rust belt cities is a pragmatic way to avoid urban sprawl and to optimize urban land use, and assessing their spatial arrangements is a vital and essential procedure. In this study, we identified four types of underutilized land: vacant lot, urban village, abandoned industrial land and remnant cultivated land. We then analyzed the spatial structuring of such areas and their interconnections along with the history of rapid urbanization in Changchun City in the period 1990-2016. We found that the underutilized lands increased rapidly as the urban areas developed; they accounted for 17.29% of the total central urban area, with the urban periphery identified as a hot spot. Three primary groups of underutilized lands with clear links in terms of spatial distribution were identified: vacant lots and remnant cultivated lands at the urban periphery; dispersed vacant lots, urban villages and abandoned industrial land at the urban core; and urban villages and abandoned industrial land in an area that developed early on, but where urbanization was inefficient. Moreover, vacant lots and remnant cultivated lands at the urban periphery were strongly related to the rapid urbanization. We found that the occurrence of different underutilized lands was linked, and this was clearly reflected in their distribution characteristics. Additionally, rust belt cities in Northeast China, like Changchun City, were confronted with more problems than underutilization of central land following rapid urbanization. Our study highlights the fact that any centralized solution to regenerating underutilized lands in rust belt cities should pay attention to their interconnections.