Volcaniclastic flow hazard zonation in the Sub-Apennine Vesuvian area using GIS and remote sensing

Steep slopes mantled by pyroclastic
deposits are favorable areas prone to generate
hazardous volcaniclastic fl ows. In Italy,
such a setting is well represented in the
Campania Region, where pyroclastic deposits
from the explosive activity of the Neapolitan
volcanoes (Ischia, Campi Flegrei, and
Somma-Vesuvius) cover the Apennine range
bordering the Campanian Plain. In order
to provide a useful contribution to the mitigation
and prevention of these calamitous
natural events, this work presents a multidisciplinary
approach to improve the understanding
of the volcaniclastic fl ow hazard
zonation in an Apennine area of 340 km2
surrounding the Somma-Vesuvius volcano.
The disruption proneness index (DPI) was
calculated in order to identify the drainage
basins potentially prone to generate volcaniclastic
fl ows. This index is obtained by combining
satellite and morphometric data in a
geographic information system (GIS) environment.
It is calculated for 1100 drainage
basins, considering the main parameters
infl uencing the slope stability (slope angle,
basin shape factor, curvature, relative relief,
aspect, and land cover). The land cover
mapping is obtained from Landsat data
and airborne high-resolution images, while
the morphometric parameters are derived
from a digital elevation model (DEM) with
a cell size of 10 m. The result is a zonation
map that classifi es the drainage basins
according to different degrees of proneness
to generate volcaniclastic fl ows (low, moderate,
high, and very high). The drainage
basins falling within high and very high
classes are 66%, while 28% fall in the moderate
class, and the remaining 6% fall in the
low proneness class.