The conjectural philological survey using G.I.S.-based tools. A case study: Carignano

The conjectural philological survey of urban centres, devised at the end of the Seventies by a research group headed by Prof. A. Cavallari Murat of the Turin Politecnico is based on a perceptive analysis of the entities that made up the urban texture of an urban centre. The information obtained, coded according to standard UNI 7310/74, is in the form of a graphical representation in which the various themes are rendered through colouring, point symbols, different line styles, and a certain number of labels. The above-mentioned UNI standard admits a single subjective interpretation of conditions that are deemed pathological for the urban texture through a two-colour representation. With the use of GIS-based tools it becomes possible to create two closely interlinked information structures: a database and a map-generating system. The database has the potential of storing all relevant information that may be of use, enabling the researcher to browse through the data, submit queries and handle the outcome of the search. Furthermore, the database can also generate maps, which in their turn are linked to the database, so that the latter can also be explored through direct hot-links on the maps. This makes it possible to produce diversified representations. A new interpretation of standard UNI 7310/74 has been developed, on the basis of a study conducted in connection with a survey of the historical centre of the City of Carignano, a small town characterised by significant medieval and baroque elements. This new interpretation serves as the basis of new analyses, focusing on the structuring of the urban texture, the detection of degnerative aspects, a diachronic perception of the way the city centre has evolved over the centuries.