Urban landslides

220

150

Abstract. Since 1990, we have maintained a database of historical information on landslides and floods in Italy, known as the National Research Council's AVI (Damaged Urban Areas) archive. The database was originally designed to respond to a request of the Minister of Civil Protection, and was aimed at helping the regional assessment of landslide and flood risk in Italy. The database was compiled in 1991-1992 to cover the period 1917 to 1990, and then updated to cover systematically the period 1917 to 2000, and nonsystematically the periods 1900 to 1916 and 2001 to 2002. The database currently contains information on more than 32 000 landslide events occurred at more than 21 000 sites, and on more than 29 000 flood events occurred at more than 14 000 sites. Independently from the AVI archive, we have obtained other databases containing information on damage caused by mass movements and inundations, daily discharge measurements and solid-transport measurements at selected gauging stations, bibliographical and reference information on landslides and inundations, and a catalogue of National legislation on hydrological and geological hazards and risk in Italy. The databases are part of an information system known as SICI (an Italian acronym for Sistema Informativo sulle Catastrofi Idrogeologiche, Information System on Hydrological and Geomorphological Catastrophes), which is currently the largest single repository of historical information on landslides and floods in Italy. After an outline of the history and evolution of the AVI Project archive, we present and discuss: (a) the structure of the SICI information system, including the hardware and software solutions adopted to maintain, manage, update, use and disseminate the information stored in the various databases, (b) the type and amount of information stored in each database, including an estimate of their completeness, and (c) examples of recent applications of the information system, including a web-based GIS system to Correspondence to: F. Guzzetti (fausto.guzzetti@irpi.cnr.it)show the location of sites historically affected by landslides and floods, and an estimate of geo-hydrological (i.e. landslide and flood) risk in Italy based on the available historical information.

“…At least 500 people were left temporarily unemployed (Crescenti, 1986). The economic loss was estimated at 1000 billion 1982/Lire (Alexander, 1989) (Fig. 1).…”

Section: Appendixmentioning

confidence: 99%

Information system on hydrological and geomorphological catastrophes in Italy (SICI): a tool for managing landslide and flood hazards

Guzzetti

Tonelli

2004

220

150

“…The latter is a function of landslide volume and velocity. Table 5 was prepared based on the review of the limited literature on the subject (Alexander, 1989;Michael-Leiba et al, 1999;Fell, 2000), the analysis of the damage caused by slope failures in Umbria (Felicioni et al, 1994, Alexander, 2000Cardinali et al, 2000;Antonini et al, 2001), and our experience and judgement. A crude estimate (i.e.…”

Section: Elements At Risk and Their Vulnerabilitymentioning

confidence: 99%

“…The single slope failure involved the movement of 342 hectares of urban and suburban land, damage to two hospitals and the Faculty of Medicine at Ancona University, damage to or complete destruction of 280 buildings with a total of 865 apartments, displacement of the main railway and coastal road for more than 2.5 km, one (indirect) death, and the evacuation of 3661 people (Crescenti, 1986;Catenacci, 1992). The economic loss was estimated at US$ 700 million (Alexander, 1989).…”

Section: Introductionmentioning

confidence: 99%

A geomorphological approach to the estimation of landslide hazards and risks in Umbria, Central Italy

Cardinali

Reichenbach

Guzzetti

et al. 2002

259

142

Abstract. We present a geomorphological method to evaluate landslide hazard and risk. The method is based on the recognition of existing and past landslides, on the scrutiny of the local geological and morphological setting, and on the study of site-specific and historical information on past landslide events. For each study area a multi-temporal landslide inventory map has been prepared through the interpretation of various sets of stereoscopic aerial photographs taken over the period 1941-1999, field mapping carried out in the years 2000 and 2001, and the critical review of site-specific investigations completed to solve local instability problems. The multi-temporal landslide map portrays the distribution of the existing and past landslides and their observed changes over a period of about 60 years. Changes in the distribution and pattern of landslides allow one to infer the possible evolution of slopes, the most probable type of failures, and their expected frequency of occurrence and intensity. This information is used to evaluate landslide hazard, and to estimate the associated risk. The methodology is not straightforward and requires experienced geomorphologists, trained in the recognition and analysis of slope processes. Levels of landslide hazard and risk are expressed using an index that conveys, in a simple and compact format, information on the landslide frequency, the landslide intensity, and the likely damage caused by the expected failure. The methodology was tested in 79 towns, villages, and individual dwellings in the Umbria Region of central Italy.

“…This attitude allowed some authors to calculate the costs of damages due to slope instabilities within many environments around the world: from 1972 to 2007, landslides and rockfalls cost EUR 520 million and caused 32 fatalities in Switzerland (Hilker et al, 2009), while in the United States a USD 1-2 billion expense in economic losses and about 25-50 deaths per year have been estimated (Schuster and Fleming, 1986), e.g., USD 9 million expense in only direct cost losses in Colorado during 2010 (Highland, 2013). Historical research indicates that more than 50 593 people died, went missing or were injured in 2580 landslides and floods in Italy, where 26.3 % of the 8102 municipalities have been hit by slope instabilities between 1279 and 2002 (Guzzetti et al, 2005b); economic loss related to the single destructive landslide at Ancona (Marche region) in 1982 was estimated at USD 700 million (Alexander, 1989). On the global scale, 2620 landslides were recorded during the 7-year period of [2004][2005][2006][2007][2008][2009][2010], causing a total of 32 322 fatalities (Petley, 2012).…”

Section: Introductionmentioning

confidence: 99%

Detailed and large-scale cost/benefit analyses of landslide prevention vs. post-event actions

Salbego

Floris

Busnardo

et al. 2015

Abstract. The main aim of this paper is to test economic benefits of landslide prevention measures vs. post-event emergency actions. To this end, detailed-and large-scale analyses were performed in a training area located in the northeastern Italian pre-Alps that was hit by an exceptional rainfall event occurred in November 2010. On the detailed scale, a landslide reactivated after 2010 event was investigated. Numerical modeling demonstrated that remedial works carried out after the landslide -water-removal intervention such as a drainage trench -could have improved slope stability if applied before its occurrence. Then, a cost/benefit analysis was employed. It defined that prevention would have been economically convenient compared to a non-preventive and passive attitude, allowing a 30 % saving relative to total costs. On the large scale, one of the most affected areas after 2010 event was considered. A susceptibility analysis was performed using a simple probabilistic model, which allowed to highlight the main landslide conditioning factors and the most hazardous and vulnerable sectors. In particular, such low-cost analysis demonstrated that almost 50 % of landslides occurred after 2010 event could be foreseen and allowed to roughly quantify benefits from regional landslide prevention. However, a large-scale approach is insufficient to carry out a quantitative cost/benefit analysis, for which a detailed case-by-case risk assessment is needed. The here proposed approaches could be used as a means of preventive soil protection in not only the investigated case study but also all those hazardous areas where preventive measures are needed.