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Titel |
Recent changes in rainfall characteristics and their influence on thresholds for debris flow triggering in the Dolomitic area of Cortina d'Ampezzo, north-eastern Italian Alps |
VerfasserIn |
M. Floris, A. D'Alpaos, C. Squarzoni, R. Genevois, M. Marani |
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 ; 10, no. 3 ; Nr. 10, no. 3 (2010-03-26), S.571-580 |
Datensatznummer |
250008013
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Publikation (Nr.) |
copernicus.org/nhess-10-571-2010.pdf |
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Zusammenfassung |
In this paper, we examine variations in climate characteristics near
the area of Cortina d'Ampezzo (Dolomites, Eastern Italian Alps),
with particular reference to the possible implications for
debris-flow occurrence. The study area is prone to debris-flow
release in response to summer high-intensity short-duration
rainfalls and, therefore, it is of the utmost importance to
investigate the potential increase in debris-flow triggering
rainfall events. The critical rainfall threshold is agreed to be a
crucial triggering factor for debris-flows. Data from a monitoring
system, placed in a catchment near Cortina (Acquabona), show that
debris-flows were triggered by rainfalls with peak rainfall
intensities ranging from 4.9 to 17.4 mm/10 min.
The analyses of meteorological data, collected from 1921 to 1994 at
several stations in the study area, show a negative trend of annual
rainfall, a considerable variation in the monthly rainfall
distribution, and an increase in the temperature range, possibly
related to global climate changes. Moreover, high-intensity and
short-duration rainfall events, derived from data collected from
1990 and 2008, show an increase in exceptional rainfall events. The
results obtained in a peak-over-threshold framework, applied to the
rainfall data measured at the Faloria rain gauge station from 1990
to 2008, clearly show that the interarrival time of over-threshold
events computed for different threshold values decreased in the last
decade. This suggests that local climatic changes might produce an
increase in the frequency of rainfall events, potentially triggering
debris flows in the study area. |
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