THE 1999-2001 RESEARCH PROGRAM

With the 1999-2001 program the CNR-GNDCI AVI project enters a new phase. After the inventory was carried out in the early nineties, and the historical archive organisation was completed between 1993 and 1998, the new phase of the project is aimed at the analysis and use of the historical information and at its integration with geological and hydrological data to assess flood and landslide risk at the regional scale, and to support regional planning.

The devastating mud and debris flows that occurred in May 1998 at Sarno and Quindici in Campania Region gave rise to new national legislation on hydrological and geological protection. This consists principally of the Decreto del Presidente del Consiglio dei Ministri (DPCM 267/1998) of 29-8-98, witch qualifies both DL no. 180 of 11-5-98 and L. 183 of 18-5-89, the main soil conservation law. The DPCM requires flood, landslide and erosion hazards to be mapped in detail and this information to be compared with elements at risk in the landscape in order to identify the locations of major risk to people, buildings and infrastructure.

Historical information on landslide and flood collected, organised and made available by the AVI project are among the data the new legislation suggests to be used to evaluate landslide and flood hazard, and to map areas at high risk. This is an important recognition for the value of historical data (and of historical research on natural catastrophes) and for the role of the AVI project; the first of its kind for flood and landslide risk assessment.

The various research and organisational activities carried out within the AVI project from 1991 to 1998 resulted in computer databases and catalogues of damaging landslide and flood events occurred in Italy in the 20^th century. The archives and catalogues, far from being an hydro-geological risk map, represent the most accurate and updated map of the spatial and temporal distribution of landslide and flood events ever prepared for Italy. Research planned for 1999-2001 is mostly aimed at testing the possibility of using the AVI archives and catalogues to help assessing landslide and flood hazard, and to map areas at higher risk.

THE PROGRAM       

The success obtained by the AVI products and in particular by the catalogues and the databases, and the recent institutional recognition of the value and role of the AVI project, clearly show that the collection, storage and analysis of historical information on hydrological and geological catastrophes must continue. A new question arises: now that we have such a large database of historical information, how can we use it to improve our ability to forecast dangerous event and to define and map areas at risk?

After the main inventory was completed in the early nineties, project’s activities have focused on the digitisation of the available information and documents (mostly on paper), on the organisation and management of the database, and on strategies for the dissemination of the information using a variety of tools, including maps, books, CD-ROMs and the Internet. To these complex and costly tasks, that will certainly continue in the future, the 1999-2001 program adds new tasks aimed at extending (mostly in the past) the temporal extent of the AVI database, and at investigating possible applications and limits of the historical information for the evaluation and assessment of flood and landslide hazard and risk. Within this framework, the  goals of the 1999-2001 program are:

-        to maintain, update and refine the database by collecting new information, by extending in the past the time-span of the archive, and by evaluating the database completeness, reliability and representativness;

-        to upgrade the current capabilities of the AVI information system, improving the tools for an efficient interactive data-dissemination;

-        to experiment with possible applications of the historical information, producing thematic catalogues, defining a list of the most severe hydro-meteorological events that resulted in catastrophic inundation or landslides; and devising guidelines for the use of historical information to assess flood and landslide hazard and risk.

Database maintenance and upgrade

The value of an historical series is inherent to its length and completeness. For this reason maintenance and upgrade of the AVI database remain an important goal of the project. During the 1991-2001 program, the database will be extended to the year 1998, and an attempt will be made to experiment with a real-time update of the archive using information available on the Internet. The main source of information will remain the newspapers, and the same searching techniques used with success in the past will be exploited. The database will be upgraded also by searching libraries of newspapers, historical archives and repertoires on natural catastrophes that were not searched exhaustively during the previous phases of the inventory.

There are three reasons to upgrade the database and to try to extend it in the past. The first reason has to do with the fact that when the AVI inventory was planned it was decided to relay heavily on the newspapers of the 20^th century (actually, from 1918 to 1990). This has allowed to collect in a limited time and with scarce resources an enormous amount of information that, as a drawback, is not homogeneously distributed (in space and time). The catalogue of landslide or flood events is therefore somewhat biased by the cultural and social situation in each region, and by the availability and diffusion of newspapers. The second reason refers to the technique used to carry out the inventory, that was completed by 14 groups with different experience and background. To an extent this has contributed to the lack of homogeneity of the database. The last reason refers to the decision to start collecting information from 1918, when the Italian State (a Monarchy at the time) was restructuring the technical services, including the hydrological service. Hence, if from about 1920 daily rainfall measurements and daily water levels at several gauging stations are available for comparison with information on catastrophic landslide and flood events, there is a loss of memory for all the events with a return period exceeding a century.

Searching repertoires and historical compilations, 19^th century catalogues, and academic journals will extend the temporal coverage of the AVI database from the present 80 years to 150 years or more, limiting the problem due to the events with a return period close to a century. The integration of the AVI database with local, high quality sources (mostly chronicles) covering few or several centuries, is not meant to systematically improve the database, but rather to investigate the limitations of the AVI database in regions with different culture and various geo-morphological settings, to compare detailed historical chronicles available for limited areas, and to estimate the time and economic resources needed for a nation-wide upgrade of the AVI database.

Upgrade of the information system

The AVI information system was started as an experimental tool to disseminate historical data. The information system is now a complex and integrated tool aimed at a large variety of users interested in landslide and flood hazard and risk in Italy. Users include central, regional and local governments; scientists; geologists, engineers and planners; civil protection personnel; and concerned citizens.  Following the DPCM n° 267, the requests of information, data and publications (in particular the Catalogue of information on sites historically affected by landslides and floods and its electronic version, the Mappavi software) have largely increased. The amount of data currently available and the information that it is foreseeable will be collected in the next few years, require proper technical support and professional expertise to improve the dissemination of the information, to help scientists in their effort to assess landslide and flood hazard, and to facilitate storage, maintenance and efficient use of an increasing amount of information.

With this respect, the “strategic” goal is to transform the information system in the core (or the “engine”) of the entire AVI project. During the 3-years program we plan to increase the information available in digital form, to upgrade the system for data analysis and information dissemination; to prepare new synoptic maps and new catalogues, and to distribute them in both paper (hard) and digital (soft) copy.

Use of the historical information

The use of the historical information collected, stored and organised by the AVI project represents an innovation of the 1999-2001 program. During the 3-years program attempts will be made to test different applications of the available historical information on landslide and flood events, and on the new information that will be collected during the program. Experiments will be carried out on three subjects: the production of thematic catalogues of events with human consequences and of catalogues that caused damage to the infrastructures; the production of a catalogue of the strongest (i.e., most severe) meteorological events that resulted in landslides or floods; and the development of techniques for the integration of historical, mostly qualitative, information with geological and geo-morphological data to get a better assessment of landslide and flood hazard.

The production of catalogues of events with human consequences and of events that caused damage to the infrastructures will help defying the frequency and intensity (magnitude) of potentially damaging events. The catalogues will be helpful to insurance and re-insurance companies and, by comparison with already available data on human consequence caused by other catastrophic events (natural and human induced), will be used to assess the economic impact of landslides and floods, and to evaluate acceptable societal risk levels. If necessary, a new synoptic map showing the distribution of landslides and floods that caused human consequences or that resulted in damage to the infrastructures will be prepared for publication.

The production of a nation wide catalogue of the strongest (i.e., most severe) hydro-meteorological events that resulted in landslides and floods has the purpose to define the physical (meteorological, hydrological, geological, morphological) and social-economical (type and extent of damage) characteristics of the most damaging events. Based on the “Final Regional Reports” prepared by each research team at the end of the inventory, and on the analysis severe events, all major hydro-meteorological events will be identified and studied. For each event, the type and extent of all ground effects will be defined. If necessary the information currently available will be refined and integrated. Results will be compared with existing meteorological, hydrological, geological and morphological data.

Lastly, guidelines for a proper and thoughtful use of historical data for the evaluation of landslide and flood hazard and risk will be proposed. Guidelines are badly needed to prevent (or at least limit) the abuse and the misuse (some of which recent) of the historical information on landslides and floods inventoried by the AVI project and distributed through the AVI information system.