Cultural Heritage Risk Map of the Sicily Region

The Sicilian Risk Map was developed by the Regional Centre for Planning and Restoration, a research institute of the Regional Department for Cultural Heritage. The project, funded through European structural funds, integrates and updates the national study, adapting it to the specific characteristics of the region.

The Risk Map organises data and geospatial data within a Geographic Information System and supports the study of Sicily’s cultural heritage, defining a research framework that interprets the relationships between territorial hazard factors and the presence and dynamics of deterioration processes affecting cultural heritage.

The assessment of hazards, the identification of the main vulnerability parameters and critical areas make it possible to formulate appropriate questions, verify responses, establish potential intervention priorities, define careful territorial planning and develop policies for the conservation, management and sustainable use of cultural heritage.

Scheduled Conservation is a practice that must be implemented systematically across the territory in order to ensure effective management of cultural heritage. Its implementation requires detailed and constantly updated knowledge of the extent and distribution of this heritage, the various hazard factors that may damage it, its state of conservation and/or the causes and dynamics of the deterioration processes affecting it. It is therefore necessary to organise this knowledge within a system that links cartographic and textual documents through digital tools, ensuring that information can be continuously updated, disseminated and shared.

The Cultural and Environmental Heritage Risk Map can meet this need effectively if it is managed at regional level, rather than at national level as in the previous approach established by the Central Institute for Restoration, and if it provides genuinely reliable data. The Sicilian Regional Project was developed within this framework, populating the Information System with a sufficiently extensive dataset, managed with a much higher level of geographic accuracy than the original system and supported by an IT architecture that ensures continuous updating and integration of information.

As part of the project, conceptual consistency with the national system was continuously verified, together with field surveys and the validation of records. A new record format was also defined, containing, among other elements, general information on each heritage asset and information supporting emergency management. New calculation models were developed for first-level individual risk and local risk, along with the architecture of the Sicilian Risk Map GIS. Approximately 1,400 ICCD catalogue records were also acquired and linked to the heritage assets contained in the system, among other activities.

The project also included the acquisition and loading of cartographic base maps into the geodatabase, the development of web applications supporting identification records, heritage records, architectural, archaeological and heritage vulnerability assessments, as well as validation activities. Handheld-device interfaces were developed for field surveys, asset identification and geolocation, together with interfaces and procedures for calculating vulnerability, hazard and risk. Finally, the hardware and software configuration of the GIS was completed.

At the end of the field survey activities, it was possible to generate the “new” Monumental Heritage Distribution Map. This provides a uniform distribution of data across the entire regional territory, with a quantity and richness of associated information useful for analysing vulnerability and individual and heritage-related risk, on a scale never previously achieved.

The heritage assets currently recorded in the alphanumeric database and Geodatabase are:

• 8,120 Architectural Heritage Assets, including:
  • 966 Complexes,
  • 2,243 Components
  • 4,911 Individual Assets
• 1,886 Archaeological Heritage Assets, including:
• 125 Complexes,
• 486 Components
• 1,275 Individual Assets
• 178 Areas of Interest

The database is further enriched with datasets relating to protected heritage assets, historical records and a wide range of other information essential for heritage management. Geographic accuracy is ensured both by the finer scale used to analyse hazard dynamics and by the georeferencing of the surveyed heritage. Vulnerability and seismic vulnerability records have also been produced for approximately 2,700 surveyed architectural and archaeological heritage assets.

The Monumental Heritage Distribution Map, produced using these data and representing heritage assets according to property type (A Assets, MA Assets, Areas of Interest), is only one of the possible representations provided by the GIS through the alphanumeric attributes derived from the catalogue records.

The system makes it possible to thematically represent the data according to all available attributes. Some examples include: protected or unprotected status, asset type (complex, component or individual asset), original function (civil, religious, funerary, military, infrastructure and services), type of area (natural, urban, landscape, archaeological), site morphology (plain, hill – gentle slope, hill – steep slope, hill – ridge, etc.), modern use (worship, tourism, residential use, storage/warehouses, laboratories/offices, etc.), average number of visitors per year, and accessibility (pedestrian or vehicular).

System description

The system allows users to enter, view and modify data relating to architectural and archaeological heritage assets catalogued in Sicily. Access to the portal is governed by an authentication and authorisation system that filters access and allows specific system functions to be used only by certain user profiles: administrator, data-entry operator, validator and reader. The profile structure follows a hierarchical model in which the administrator includes the validator’s functions as well as user management functions. The validator can enter new data and validate or reject data entered by cataloguers. Cataloguers can only enter, modify and view data relating to the various heritage assets. Readers can access all entered and validated data in read-only mode. The validation process follows a simple workflow in which, while a record is being completed, it remains in an ‘incomplete’ status and is therefore not visible to readers or to the cartographic and risk analysis tools.

Once completed, an email notifies the validators that the record can be validated or rejected. If the record is rejected, a notification is sent to the cataloguer, who can then make the necessary changes. Only validated records are used as input data for the analysis algorithms and cartographic tools.

Through a search tool, each user can search for all heritage assets with incomplete, complete, validated or rejected records, helping to speed up the completion of catalogue data. A heritage asset record can also be searched for by entering information relating to its location, name or type.

The search results provide a visual indication of the status of the three records associated with a heritage asset.

The web interface is structured to reproduce the three descriptive records — identification, heritage and vulnerability — in the same format as the paper forms.

Individual records are organised into sections so that users manage a limited amount of data before each save operation, thus avoiding session timeout issues typical of web applications. Data are saved section by section, although users can move from one section to another without saving. At any given time, the record of the heritage asset being completed contains a certain amount of data already stored in the DB, regardless of whether the record has been completed. To prevent concurrency issues, optimistic locking is implemented for each individual heritage asset whenever any data relating to it are written.

To speed up data entry, an XML data import procedure has been implemented, allowing data exported from the cataloguers’ handheld devices to be written to the DB through a simple upload.

The WebGIS component was developed entirely ad hoc in a Java environment, using the ArcIMS Java Connector classes. In addition to standard navigation functions (panning, zooming, etc.), the WebGIS section of the portal provides advanced and customised functions for identifying and consulting heritage assets, unlimited previous zoom, spatial searches using a circular buffer, selection of heritage assets using polygons, searches based on attributes stored both in the GeoDB and in the alphanumeric DB, and map visualisation in both filter and highlight modes.

Other functions include: selection and display of multiple layers, including raster layers, measurement of the distance between two points, measurement of a polygonal path, zooming to the overview map scale, map printing, and on-the-fly projection of cartographic data into the most widely used coordinate systems in Italy (Gauss-Boaga, UTM 32 and 33, etc.).

The thematic mapping of data is performed by selecting attributes / indicators stored within a DBMS that manages all indicators through a dictionary: textual, numerical and calculated. Calculated indicators, in particular, are assigned values using a mathematical formula that can be configured at runtime through a dedicated web interface, which establishes relationships with other simple or calculated indicators associated with a specific location. Each indicator can be defined at provincial, municipal, census-area or individual heritage asset level. Based on this structure, the map can be thematically represented dynamically, making it possible to generate a virtually unlimited number of maps according to the number of indicators available in the system. Once a thematic representation has been generated, the loaded classification can be modified through a class management system that allows users to change the colour and value ranges assigned to each class and save the selected configuration to the DB.

The WebGIS interface also provides cartographic editing functions that allow users to create and/or move point-based heritage assets and asset boundaries.

To support cataloguers, ad hoc software was developed for the mobile environment to carry out heritage asset identification and geocoding directly in the field, using the Microsoft .NET CE Framework, the SQL Server CE database and ArcPad Application Builder.

The MS .NET CE application allows alphanumeric data for each individual heritage asset to be entered and modified through a series of forms. The application also provides access to ArcPad functions, specifically configured for the CRS application, giving users access to all customised cartographic editing functions and the acquisition of X,Y coordinates.

The ArcPad customisations mainly include the ability to create a point on the map representing the entrance to a heritage asset and to define its perimeter, move the point representing the entrance, retrieve X,Y coordinates including via GPS, perform spatial searches or searches based on the asset’s identification code passed to ArcPad by the CRS application, check whether an asset associated with that code is already present on the map, and zoom to the area where the selected asset is located, etc.