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Logical model
The GIS Risk Map is a system of alphanumeric and cartographic databanks, capable of exploring, superimposing and processing information concerning the potential risk factors posed to the cultural heritage.
A statistical approach was used in the construction of the model, on the basis
of which individual items were evaluated as "units" of a "statistical population"
upon which an attempt is made to assess the level of risk. The system takes as a
minimum geo-referenceable element the single architectural and archaeological
immovable item (statistical unit) and the municipality as the minimum element
of the territorial scale (territorial unit). Because movable items (paintings on
wood, canvasses, archaeological finds etc) are not geo-referenceable, they have
been linked with the associated immovable item “container”, that corresponds with
the aforementioned dimensional scale.
The risk factors have been divided into:
- Individual Vulnerability (V) - namely a function that indicates the level of exposure
of a given item to the aggression of territorial environmental factors;
- Territorial Danger (P) - namely a function that indicates the level of potential
aggressiveness of a given territorial area, irrespective of the presence or otherwise
of the items.
In this way it is possible to define these two components and evaluate their intensity by means of the extent of the physical quantities that contribute in determining the two parameters.
In order to build the Risk Model, three different domains were identified, valid for Vulnerability as well as Danger.
The domains identified for Vulnerability (V) are:
the Environmental-Air domain (defined by the aspect of the surface), V1; the Static-Structural domain (defined by the constructional and static-structural characteristics), V2; the Anthropic domain (defined by use and safety), V3.
Similarly, the domains identified for Danger (P) were:
the Environmental-Air domain (characterised by climatic and micro-climatic factors and air pollutants), P1; the Static-Structural domain (defined by the geomorphological characteristics of the ground and the subsurface), P2; the Anthropic domain (defined by demographic and socio-economic dynamics), P3.
The model described above allows Risk (R) to be expressed as a general function of
the Vulnerability (V) components, related to each unit of population, and of Danger
(P), related to each territorial area on which the item is located.
R = R(V1,V2,....Vn, P1,P2,...Pn)
where R indicates the Risk and configures itself as a weighted average of the Vulnerability (V) and Danger (P) Indicators.
The system is created according to a client-server type modular structure, and is organised at a central level (Central System) and a local level (Remote Systems).
