Inventory of information on sites historically affected by landslides and floods


In 1989 the Minister of Civil Protection requested the National Research Council (CNR), Group for Hydrogeological Disasters Prevention (GNDCI), to compile an inventory of sites historically affected by landslides and floods in Italy, for the period 1918-1990. Between 1991 and 1992 seventeen teams collected information on mass-movements and floods. A total of 22 journals were systematically searched and 350,000 newspaper issues were screened. About 150 experts were interviewed and 1000 published and unpublished technical and scientific reports were reviewed. The inventory was updated for the period 1991-1994 by searching 55 local or regional journals, for a total of about 70,000 newspaper issues screened. Information on more than 17,000 mass-movements and more than 7000 floods was stored into a computer database. Since 1994 efforts have been made to assess the completeness and reliability of the historical archive, to test its consistency and to perform a preliminary validation of the information content. The computer database was migrated to a relational structure and systematically searched for errors and inconsistencies, most of which were corrected.

In 1996 a preliminary map of sites affected by mass-movements and inundation was published. Since then all sites known to have been affected by mass-movements or inundation were mapped as points at 1:100,000 scale. Sites for witch the location was uncertain were mapped in the municipality chief town. A degree of certainty in the location was given to each site.

In 1998 a revised version of the sinoptic map showing the location of more than 15,000 sites (9086 landslides and 6456 floods) affected by catastrophic events for the period 1918-1994 will be published. The new map shows the location of 2608 landslide sites and 2317 inundation sites affected recursively, i.e., more than once, and, far from being a map of hydrological and geological hazard or risk, provides the most accurate and updated synoptic view of the distribution and frequency of catastrophic events in Italy.

In spite of the limitations due to the complexity of the Italian territory, the different awareness of the impact of landslides and floods on the territory, and the limited resources available for the inventory and its maintenance, the result of the inventory represents the most comprehensive source of information on mass-movements and floods for this century ever prepared for Italy.