Spiky Metropolitan Landscapes: An Urbanometric Analysis of Growing Agglomerations

The spatial configuration of urban systems has garnered significant interest from various disciplines, including urban planners, economists, and ecologists, due to its interconnectedness with various aspects of sustainable development. Research on urban form suggests a departure from the conventional model of a gradually declining density gradient from the city center, giving way to a “spiky” urban landscape characterized by a heterogeneous polycentric pattern. This study aims to examine the recently emerging spiky structure of an urban agglomeration and its determinants, providing insights into the potential prospects of cities. We adopt a new quantitative modeling approach inspired by spatial econometrics and coined here ‘urbanometrics’. By utilizing and testing spatial dependence urbanometric models, we seek to elucidate the factors driving these changes, with a specific focus on pluriform urban sprawl in the Mediterranean region, specifically the Izmir city-region. The findings indicate that since the early 2000s, the Izmir city-region has experienced simultaneous decentralization and the emergence of multiple centers, with sharp differences. Furthermore, the results demonstrate that the expansion of highway infrastructure, population growth, and existing convertible (agricultural or forest) land contribute to urban sprawl and the emergence of a “spiky” urban landscape.