A GIS-based procedure for residential urban fabrics characterisation. The case study of Bologna

The digitalisation process of the urban context by creating 3D-city models/digital twins is significant in supporting sustainable urban planning and development. A digital twin/3D-city model is able to meet various objectives at many scales and spatio-temporal dimensions, serving different disciplines and sectors and offering predictive simulations. GIS (Geographic Information System) is the basis of the City Information Model and is responsible for data collection, interpretation, visualisation, analysis and interaction. In the case study of Bologna, GIS allows to (i) formalise a procedure for the characterisation of the urban fabrics, mainly residential and built between the first and the second half of the XXth century; (ii) visualise density analyses on the territory; (iii) identify a set of urban areas for evaluations at the building scale by integrating data from building permits archival documents for validating the characterisation procedure. The addition of new information layers directly viewed on the territory in GIS software (i.e. energy and environmental performance resulting from Life Cycle Analysis) contributes to the definition of a decision-support tool for urban planning. The simulations of different scenarios and rates of interventions on the building heritage in a predefined time interval aim to support the assessment of decarbonisation goals and to define mitigation and resilience strategies to climate change at a large scale.