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Titel |
Analyzing the spillway failure of the Montedoglio dam in Central Italy |
VerfasserIn |
A. Tarpanelli, T. Moramarco, S. Barbetta, F. Melone, N. Berni, C. Pandolfo, R. Morbidelli |
Konferenz |
EGU General Assembly 2012
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 14 (2012) |
Datensatznummer |
250062407
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Zusammenfassung |
The Montedoglio dam, built in the 1980s for irrigation and drinking water purposes, is an
important reservoir on the Tiber River located in central Italy. The earth-fill dam is
64.30 m high with a drainage area of 276 km2. The water storage volume, with the
water at the height of the spillway, is approximately 153 millions m3. On December
29, 2010 during final tests of the dam consisting to raising the reservoir level to
the spillway crest, three concrete blocks of the spillway collapsed causing large
damages in the territory downstream mainly to agriculture, infrastructures and other
constructions (over 100 millions of euros of economic losses), luckily without casualties
thanks also to timely action of the national/regional Civil Protection system. The
discharge hydrograph following up the Montedoglio spillway collapse and its routing
along the Tiber river valley are investigated here. The mathematical modelling of
the reservoir depletion allows advancing well-founded hypotheses on the breach
formation and in particular on the time interval in which the spillways collapsed found
equal to 0.02 hours. The analysis is based on the recorded water reservoir level
during the catastrophic event and on the comparison between the computed outflow
discharge hydrograph and the one recorded at Gorgabuia equipped section located just
downstream Montedoglio dam. The consequent dambreak flood wave is propagated
downstream by using a one-dimensional model for flood wave routing and, based
on the comparison between the flooded area extension estimated by the hydraulic
model and the one observed through surveys and inspections carried out during
the catastrophic event, the roughness calibration is addressed assessing different
Manning roughness coefficient values for the main channel and the floodplains,
respectively. For the analysis of the catastrophic event, data on water reservoir levels,
river cross-sections geometry, discharges recorded at two gauged river sites and
flooded area extension have been collected, thus getting a valuable knowledge which
can be of support to improve the understanding and the management of dambreak
events. |
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