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| Titel |
Is anthropogenic land-subsidence a possible driver of riverine flood-risk dynamics? A casa study in Ravenna, Italy. |
| VerfasserIn |
Francesca Carisi, Alessio Domeneghetti, Attilio Castellarin |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250144063
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| Publikation (Nr.) |
 EGU/EGU2017-7843.pdf |
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| Zusammenfassung |
| Can man-induced or man-accelerated land-subsidence modify significantly riverine
flood-hazard in flood-prone areas? We address this question by investigating the possible
changes in flood hazard over one of the most prominent cases of anthropogenic
land-subsidence in Italy, a 77-km2 area around the city of Ravenna. The subsidence rate in
the area, naturally in the order of a few mm/year, increased dramatically after World War II as
a consequence of groundwater pumping and natural gas extraction, exceeding 110
mm/year and resulting in cumulative drops larger than 1.5 m in roughly 100 years. The
Montone-Ronco and Fiumi Uniti rivers flow in the southern portion of the study area, which
is protected from frequent flooding by levees. We simulated the inundation events associated
with different potential levee-breaching configurations by using a fully two-dimensional
hydrodynamic model constructed on the basis of four different floodplain geometries: the
current topography and a reconstruction of ground elevations before anthropogenic
land-subsidence, both neglecting man-made infrastructures, and the current and historical
topographies completed with a representation of road and railway embankments and
main land-reclamation channels. Our results show that flood-hazard changes due to
anthropogenic land-subsidence are limited (e.g. significant changes in simulated
values of water depth, h, velocity, v, and intensity, i=h⋅v, are detected in roughly
1%, 2% and 8% of the flood-prone area, in this order) and overwhelmingly lower
than those determined by the construction of road and railway embankments or
artificial channel networks (20%, 14% and 48% of the flood-prone area, respectively). |
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