The effects of growth, shrinkage, population aging and preference shifts on urban development-A spatial scenario analysis of Berlin, Germany

We observe diverse urban development trends in European cities, with processes such as population aging, growth, shrinkage, and reurbanization having unclear consequences on land use and the urban form. The effects of these processes are especially difficult to determine when they occur quickly and simultaneously. We use varying scenarios of contrasting and exceeding variants of these urban development trends to uncover possible interactions by focusing on demographic and residential preference shifts that were simulated in a previously presented land use model (Lauf et al., 2012). Using urban form indicators and landscape metrics, we determine urban to peri-urban effects. Among other interesting results, we discovered that population aging expedited by population shrinkage greatly affects land consumption. This effect is especially pronounced in the outer city due to the residential preferences of elderly people and thereby reduces urban shrinkage. In contrast, a shift in preferences toward reurbanization reduces land consumption significantly. Population aging produces synergies in terms of urban growth and landscape fragmentation and trade-offs in terms of urban shrinkage and compactness, and the opposite holds for increasing reurbanization.