Land use scenarios of future urbanization in flood prone areas: A case study in the South of Rome

Land use change modelling is an effective method to analyze the impact of future scenarios on land use patterns and assess the consequences of plans and policies, in particular for cities already vulnerable to the effects of the changing climate conditions; to propose effective responses, understanding drivers and patterns of urban growth is fundamental. This study investigates plausible urban development patterns in the X Municipality of Rome. In this municipality, the lack of regulations and policies over the past decades has produced urban forms of different kinds: a formal consolidated and an informal non-consolidated. Both formal and informal settlements are exposed to high hydrological risk, due to the obsolescence of the drainage system and the fast anthropization of rural lands. We explore plausible future land use patterns, with a particular focus on residential types of land use, up to 2050 in light of the possible construction of a new football stadium, a business centre, and new infrastructure. Each of these is fundamentally uncertain, yet each alone and in combination will strongly affect urban growth and thus results in a reshaping of the actual landscape. Therefore, there is a need to evaluate the uncertainties and the outcomes on the urban fabric over many different scenarios. For this purpose, we develop a cellular-automata based land-use change model in Metronamica. We calibrate and validate the model based on historical GIS data. For the model-driven scenario approach, we use exploratory modelling, where the results of the experiments are clustered in groups with similar patterns and scenario discovery is performed for each cluster in order to identify the conditions under which each cluster would manifest.