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| Titel |
Local models for rainstorm-induced hazard analysis on Mediterranean river-torrential geomorphological systems |
| VerfasserIn |
N. Diodato |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 4, no. 3 ; Nr. 4, no. 3 (2004-05-28), S.389-397 |
| Datensatznummer |
250001690
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| Publikation (Nr.) |
 copernicus.org/nhess-4-389-2004.pdf |
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| Zusammenfassung |
| Damaging hydrogeomorphological events are defined as one or more
simultaneous phenomena (e.g. accelerated erosions, landslides, flash floods and river
floods), occurring in a spatially and temporal random way and triggered by rainfall with
different intensity and extent. The storm rainfall values are highly dependent on weather
condition and relief. However, the impact of rainstorms in Mediterranean mountain
environments depend mainly on climatic fluctuations in the short and long term,
especially in rainfall quantity. An algorithm for the characterisation of this impact,
called Rainfall Hazard Index (RHI), is developed with a less expensive methodology. In RHI
modelling, we assume that the river-torrential system has adapted to the natural
hydrological regime, and a sudden fluctuation in this regime, especially those exceeding
thresholds for an acceptable range of flexibility, may have disastrous consequences for
the mountain environment. RHI integrate two rainfall variables based upon storm depth
current and historical data, both of a fixed duration, and a one-dimensionless parameter
representative of the degree ecosystem flexibility. The approach was applied to a test
site in the Benevento river-torrential landscape, Campania (Southern Italy). So, a database
including data from 27 events which have occurred during an 77-year period
(1926-2002) was compared with Benevento-station RHI(24h), for a
qualitative validation. Trends in RHIx for annual maximum storms of duration 1,
3 and 24h were also examined. Little change is observed at the 3- and 24-h duration of
a storm, but a significant increase results in hazard of a short and intense storm
(RHIx(1h)), in agreement with a reduction in return period for
extreme rainfall events. |
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