Societal landslide and flood risk in Italy

We assessed societal landslide and flood risk to the population of Italy. The assessment was conducted at the national (synoptic) and at the regional scales. For the assessment, we used an improved version of the catalogue of historical landslide and flood events that have resulted in loss of life,...

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Main Authors: P. Salvati, C. Bianchi, M. Rossi, F. Guzzetti
Format: Article
Language:English
Published: Copernicus Publications 2010-03-01
Series:Natural Hazards and Earth System Sciences
Online Access:http://www.nat-hazards-earth-syst-sci.net/10/465/2010/nhess-10-465-2010.pdf
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author P. Salvati
C. Bianchi
M. Rossi
F. Guzzetti
author_facet P. Salvati
C. Bianchi
M. Rossi
F. Guzzetti
author_sort P. Salvati
collection DOAJ
description We assessed societal landslide and flood risk to the population of Italy. The assessment was conducted at the national (synoptic) and at the regional scales. For the assessment, we used an improved version of the catalogue of historical landslide and flood events that have resulted in loss of life, missing persons, injuries and homelessness in Italy, from 1850 to 2008. This is the recent portion of a larger catalogue spanning the 1941-year period from 68 to 2008. We started by discussing uncertainty and completeness in the historical catalogue, and we performed an analysis of the temporal and geographical pattern of harmful landslide and flood events, in Italy. We found that sites affected by harmful landslides or floods are not distributed evenly in Italy, and we attributed the differences to different physiographical settings. To determine societal risk, we investigated the distribution of the number of landslide and flood casualties (deaths, missing persons, and injured people) in Italy, and in the 20 Italian Regions. Using order statistics, we found that the intensity of a landslide or flood event – measured by the total number of casualties in the event – follows a general negative power law trend. Next, we modelled the empirical distributions of the frequency of landslide and flood events with casualties in Italy and in each Region using a Zipf distribution. We used the scaling exponent <i>s</i> of the probability mass function (PMF) of the intensity of the events, which controls the proportion of small, medium, and large events, to compare societal risk levels in different geographical areas and for different periods. Lastly, to consider the frequency of the events with casualties, we scaled the PMF obtained for the individual Regions to the total number of events in each Region, in the period 1950–2008, and we used the results to rank societal landslide and flood risk in Italy. We found that in the considered period societal landslide risk is largest in Trentino-Alto Adige and Campania, and societal flood risk is highest in Piedmont and Sicily.
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spelling doaj.art-6b118577bbf94e9786ec00d68a6dbd0e2022-12-21T22:39:42ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812010-03-01103465483Societal landslide and flood risk in ItalyP. SalvatiC. BianchiM. RossiF. GuzzettiWe assessed societal landslide and flood risk to the population of Italy. The assessment was conducted at the national (synoptic) and at the regional scales. For the assessment, we used an improved version of the catalogue of historical landslide and flood events that have resulted in loss of life, missing persons, injuries and homelessness in Italy, from 1850 to 2008. This is the recent portion of a larger catalogue spanning the 1941-year period from 68 to 2008. We started by discussing uncertainty and completeness in the historical catalogue, and we performed an analysis of the temporal and geographical pattern of harmful landslide and flood events, in Italy. We found that sites affected by harmful landslides or floods are not distributed evenly in Italy, and we attributed the differences to different physiographical settings. To determine societal risk, we investigated the distribution of the number of landslide and flood casualties (deaths, missing persons, and injured people) in Italy, and in the 20 Italian Regions. Using order statistics, we found that the intensity of a landslide or flood event – measured by the total number of casualties in the event – follows a general negative power law trend. Next, we modelled the empirical distributions of the frequency of landslide and flood events with casualties in Italy and in each Region using a Zipf distribution. We used the scaling exponent <i>s</i> of the probability mass function (PMF) of the intensity of the events, which controls the proportion of small, medium, and large events, to compare societal risk levels in different geographical areas and for different periods. Lastly, to consider the frequency of the events with casualties, we scaled the PMF obtained for the individual Regions to the total number of events in each Region, in the period 1950–2008, and we used the results to rank societal landslide and flood risk in Italy. We found that in the considered period societal landslide risk is largest in Trentino-Alto Adige and Campania, and societal flood risk is highest in Piedmont and Sicily.http://www.nat-hazards-earth-syst-sci.net/10/465/2010/nhess-10-465-2010.pdf
spellingShingle P. Salvati
C. Bianchi
M. Rossi
F. Guzzetti
Societal landslide and flood risk in Italy
Natural Hazards and Earth System Sciences
title Societal landslide and flood risk in Italy
title_full Societal landslide and flood risk in Italy
title_fullStr Societal landslide and flood risk in Italy
title_full_unstemmed Societal landslide and flood risk in Italy
title_short Societal landslide and flood risk in Italy
title_sort societal landslide and flood risk in italy
url http://www.nat-hazards-earth-syst-sci.net/10/465/2010/nhess-10-465-2010.pdf
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AT fguzzetti societallandslideandfloodriskinitaly