Rethinking the spatial transformation of postsocialist cities: Shrinking, sprawling or densifying

This research examines the spatial transformations of postsocialist cities in the context of the polarized national urban system. Focusing on two different periods (1990-2000 and 2000-2014/2015), we study the patterns of spatial changes in 15 selected cities in Serbia in terms of urban sprawl, densification, and urban shrinkage. Using an open-source database, we analyze the relationship between the built-up area, population, and urban density to identify the types and trajectories of spatial transformations. Our results show that urban sprawl characterizes cities with growing/stable populations and those with declining populations but with different scales and dynamics over time. Despite the distinct trend of population decline, no cities were marked by compact shrinkage. Nevertheless, we identify a significant decrease in the annual change rates of the built-up area throughout the latter period in all cities, indicating a possible future decline in inefficient outward expansion. We also observed that this period gave rise to the imbalance between the pace of spatial growth of large cities and medium-sized cities. The obtained spatial patterns fit into the framework of Serbia's asymmetric urban system, with sprawl shrinkage as dominant phenomenon in urban centres ranking lower in the urban system hierarchy and less frequent sprawl growth in major urban centres. Our research results could ignite a process of redefining urban and land policies towards more efficient land use.