Reimagining the Bologna Fiera District through Nature-Based Solutions and Resilient Urban Infrastructure

This master’s thesis investigates the potential of Nature-Based Solutions (NbS) to improve stormwater management and the urban microclimate within the Bologna Fiera District, characterized by extensive exhibition halls, large asphalt parking areas, and limited green infrastructure. To address these challenges, an integrated climate-responsive retrofit strategy was developed by combining hydrological and microclimatic interventions. The methodology integrates GIS-based land-surface classification, runoff assessment using the Rational Method, and ENVI-met microclimate simulations to compare existing and proposed design scenarios. The proposed strategy includes extensive and intensive green roofs, permeable parking surfaces, rain gardens, stormwater storage tanks, additional urban vegetation, and green pedestrian corridors designed to increase infiltration, enhance rainwater retention, and improve outdoor environmental quality. The hydrological assessment demonstrates that the proposed NbS scenario reduced total stormwater runoff by 16.31% under the selected 24-hour design rainfall event. ENVI-met simulations indicate improvements in pedestrian thermal conditions through reductions in Mean Radiant Temperature (MRT), Physiological Equivalent Temperature (PET), and Universal Thermal Climate Index (UTCI), particularly within newly shaded and vegetated areas. The findings demonstrate that integrating Nature-Based Solutions provides an effective and transferable framework for simultaneously enhancing urban hydrological resilience, pedestrian thermal comfort, and environmental sustainability in large exhibition districts under increasing climate-change pressures.