During explosive eruptions the deposition of fine-grained volcanic ash fallout reduces soil permeability, favouring runoff of meteoric water and thus increasing the occurrence of catastrophic floods. A fully dynamic, twodimensional model was used to simulate flooding scenarios in the Vesuvian area following an explosive volcanic eruption. The highest risk occurs in the catchment area of the Acerra-Nola Plain N and NE of Vesuvius. This plain has a population of 70,000 living in low-lying areas. This catchment area is vulnerable to ash fall because it lies downwind of the dominant synoptic circulation and it lacks a natural outflow toward the sea. Our numerical simulations predict dangerous scenarios, even in quiescent periods, during extreme rain events (return periods of 200 years have been considered), and a significant increase in the extent of the flooded areas due to renewed volcanic activity. Based on these simulations a hazard zonation has been proposed.
|Autori:||Favalli M.; Pareschi M.T.; Zanchetta G|
|Titolo:||Delineation of syn-eruptive floods in the circumvesuvian plain (southern Italy)|
|Anno del prodotto:||2006|
|Digital Object Identifier (DOI):||10.1007/s00445-005-0011-z|
|Appare nelle tipologie:||1.1 Articolo in rivista|