Innovative Tools for Managing Historical Building. The Use of Geographic Information System and Ontologies for Historical Centers

Studies on historical urban centres have highlighted a complex cultural context necessarily referred to various disciplines and currently managed by multiple, different and highly specialized ICT instruments. Doubtless, to cope with urban heritage, either for scientific research or preservation policies, controlling and merging complicated systems of heterogeneous information is required. These compound activities are widely addressed from many different directions, through digital means, though developed often disregarding interoperability which should be, instead, highly pursued to properly represent the scope. As a matter of fact, the issue has proved to be well governed through formal conceptual representation, namely computer science ontologies, that define a set of primitives with which to model a domain of knowledge or discourse. Due to their formal structure, ontologies are used for integrating heterogeneous databases, enabling interoperability among disparate systems, and specifying interfaces to independent, knowledge-based services. They are therefore able to communicate with many of the ITC instrument commonly used in the midst of urban and architectural conservation and planning, as GIS (one of the most widespread technology used within territorial informative systems) or BIM environment (widely used in Architecture Engineering and Construction contexts). Taking advantage from this peculiarity and intending to enhance interoperability between existing systems, avoiding to introduce new models, the research proposes to use ontologies to represent the existing Risk Map, a Geographic Information System focused on risk assessment, introduced by the Istituto Centrale del Restauro (ICR, now Istituto Superiore per la Conservazione ed il Restauro, IsCR) of the Ministero per I Beni e le Attività Culturali (MIBAC; Italian ministry of cultural heritage and activities) and recently developed for urban centers. The aim of this system is to define the state of conservation of the architectural and archeological heritage, describing its characters and calculating a special index of vulnerability. This index, connected with the value of the territorial risk, allows to determine the level of the risk of missing the single heritage, so to define the priority of the interventions. A recent implementation of the Map has been dedicated, with the contribution of a group of researchers of Sapienza - University of Rome - to the historical urban center, opening the system – and adapting the model – to the reality of the shared historical buildings. This new topic asked for some important adaptations, which we can summarize as follows: 1) The definition of a multi-scalar system of digital forms, consisting in six different applications (1: Historical Centre; 2: Urban Unit-Aggregate; 3: Urban Unit-single Residential or Special Element; 4: Urban Space; 5: Building Unit; 6; Building Front), each of which georeferred. 2) The introduction of an index of transformation to be considered in combination with the index of vulnerability. 3) The possibility to manage the system also from local administration and not only from the basis of the Ministry of Cultural Goods and Activities and its peripheral sites. The Risk Map has a special task, connecting information on architecture with that of its territory and guiding the priorities of the intervention. Data collected within the system can be checked, updated and, eventually, be used for different purposes. Aiming at representing the whole Risk Map framework, the paper will introduce an ontology based model conceived as a compatible model with the existing CIDOC CRM. Triggering the very nature of ontologies, it will give the opportunity to manage together qualitative and hermeneutical information with measurements and metadata referring to argumentation and inference making, assuring therefore the representation of all assessments expressed by indexes worked out by algorithms and reasoning. The model intends to describe all the expressed contents and facilitate participation and collaboration between a large number of operators working with existing information system developed within geography, construction and public administration.