The GIANO project historical archive

Landslides and Floods in Italy in the 18^th and 19^th Centuries

 In 1987, ENEA (PAS-ISP) commissioned to the research company SGA, Storia Geoficia Ambiente, in Bologna, the completion on the GIANO project that SGA had helped to design. The three years contract required SGS to complete a systematic search, the analysis and the interpretation of historical information on the effects caused by exceptional natural events in Italy, from the year 1000 to 1985. The contract was completed by SGA in 1990, when all the documents collected and the analyses performed were delivered to ENEA.

With the GIANO project ENEA intended to start a national inventory of information on historical natural events in Italy in the last millennium. It is well known that due to the geographical, geological and human settings, vulnerability of the Italian territory is very high. Based on information on the 20th century, Italy has experienced the largest number of natural disasters in Europe, and one of the largest in the Mediterranean Region.

The goal of the project was to ascertain the spatial (geographical) and temporal extent of the effects of damaging natural events. Events considered in the inventory and in the analysis were:

• Meteorological events, including: high intensity rainfall, heal storms, draughts, heat storms, frost and ice storms, wind storms.

• Meteorological-Climatic-Geological events, including: floods, inundations, landslides, snow avalanches, sea storms, rising waters, costal and river erosions, etc.

In the project, emphasis was given to the search, collection and analysis of relevant information on:

·        Damage to the population, to structures and infrastructure, the cultural heritage, the industrial and agricultural activities, and to the natural environment (forests, woods, etc.).

·        Effects on the landscape, including erosion, landslides, inundations, surface faulting, etc.

From the GIANO archives to the AVI project database

In the attempt of extending back in time the AVI databases, the CNR-GNDCI Presidency verified if ENEA had independently produced catalogues of damaging landslides and floods events for the 18th and 19th centuries. CNR-GNDCI, through the Department of Civil Protection, asked ENEA to use the original GIANO information to prepare catalogues of landslides and floods for the 18th and 19th centuries compatible with the standards of the AVI databases. Successively, the CNR-GNDCI Presidency commissioned to the SGA the analysis of all the historical information on landslides and floods inventoried by the GIANO project, and the production of a catalogue of events for the 18th and 19th centuries compatible with the catalogues already prepared in the framework of the AVI project.

The database originally used by SGA to store the historical information on damaging natural events contained a list of geographic and thematic information on the damage to people and structures caused by landslides or floods. The original database was not designed to directly retrieve a catalogue of damaging events. The main goal of the work of SGA was then the systematic analysis of the original historical information, and its organization into a new catalogue of landslides and flooding events, covering the period 1700-1899.

A total of 177 bibliographic references (catalogues, scientific literature, sources, etc.) were systematically searched and a total of 2796 historical information (“testimonianza”) were found. The systematic analysis of the available information allowed to obtain data on the date of occurrence and the length of the natural event, the geographic location and extent, the damage to people, the structures, the farming and agricultural activities, and to the triggering causes of landslides and floods.

The landslides and foods catalogues contain a total of 356 landslide events and of 793 flood events. The following table shows the abundance of events in the two considered centuries.

According to the original classification devised by SGA (Guidoboni, 1995, pp. 53-54) the available historical information can be classified as follows:

 In addition to the catalogues of landslide and flood events, 1245 files (in Adobe Acrobat PDF format) were prepared. The files contain the scanned image of the original document (i.e., the historical source of information).

Relevant references

Guidoboni E., 1990. Storia del clima ed ecologia storica, Le Scienze, ottobre 1990, n. 266.

Guidoboni E., 1995. Dati di base e metodo di indagine: una navigazione fra effetti sismici e contesti storici, in E. Boschi, G. Ferrari, P. Gasperini, E. Guidoboni, G. Smriglio, e G. Valensise, Catalogo dei forti terremoti in Italia dal 461 a.C. al 1980, pp. 20-57, Bologna.

Guidoboni E., 1998. Human factors, Extreme Events and Floods in the Lower Po Plaine (Northern Italy) in the 16th Century, Environment and History, 4, n. 3, pp. 279-308.