Renaturalising lands as an adaptation strategy. Towards an integrated water-based design approach

The effects of soil sealing on the hydrological cycle and water resource exploitation are critical issues for the sustainable development of urbanised areas, where uncontrolled growth has led to deep changes in the hydrological balance regime. In a climate change scenario, the expected increase of rainfall results in hydrogeological and contamination issues, with severe impacts on the fragility of many territories such as small mountain cities. In this framework, renaturalising lands using Nature-based solutions can help to restore the original ecosystemic functions and to improve urban quality. To this end, this study proposes a multidisciplinary and transcalar water-based design approach, applied to the case study of the Comano Terme area in Trentino (Italy). Combining landscape design and hydraulic constructions, sustainable urban drainage devices were integrated into a slow mobility system and open-air public spaces to increase rainfallrunoff infiltration and storage. The hydrological model simulations showed how it is possible to treat part of the rainfall-runoff where it is produced, thus reducing and delaying the runoff quantities delivered to the stormwater system up to the receptor bodies. The proposed solutions merge with the existing environment and infrastructures, reconnecting the territory and enhancing its identity, while increasing urban resilience and providing social benefits.