Urban natures for urban resilience. Time-phases design for Changing Cities

Within the urban nature’s framework, the territory’s geomorphic changes due to climate change and how the build environment interacts with these spaces are of paramount importance. Specifically, the objective is to highlight how, in certain circumstances, the strong link between architecture and nature can result in a clear domination of one part on the other. This needs to be taken into account when considering the planning strategies to adopt in a specified area in order to re-establish the right systemic balance. In particular, coastal areas at risk of flooding, due to the constant rise in sea levels expected in the next fifty to one hundred years, have been analysed. These are areas that require long-term management, that goes beyond the normal characterisation of urban spaces; specifically, such areas could be defined as changing urban spaces. It is clear that the designs for these areas could not possibly do without a design parameter which is often underestimated: time. Nowadays, this is often introduced in the maintenance phase of the project, only rarely is it considered with the space component during the preliminary project. This leads to a clear predominance of the spatial parameter over the temporal one. Nevertheless, the designer is required to face up to the fact that space changes over time. Therefore, the urban environment needs to be reinterpreted, going from a static system to a dynamic one which changes with time, analogous to a living organism. Thus, a valid methodological response to the cities’ geomorphic changes is a time-phased design. Natural phenomena like floods cannot be avoided, they represent objective facts to be faced. For this reason, it is necessary to adopt resilient urban strategies, capable of transforming a traumatic event into a resource in both landscaping and economic terms. First of all, this operation requires an analytical approach which takes into account the city’s different systemic components: nature, infrastructure the settlement, and, consequently, the relationships between them. Once the guidelines have been identified, the priority will be towards the geomorphic adaptation of the land, in order to develop the area in a completely safe way, identifying three design time-phases, the current situation, after fifty years and after a century. At this point, it will be possible to adopt targeted planning strategies which will prevent the advance of the water in certain areas, follow the natural course of the floods in others, and integrate the water in the design in others. These measures do not refer to a specific planning phase, but to all of them simultaneously, making it possible to absorb the landscape’s natural changes and allowing the city to change in harmony with them.