Page 3 - Barrocu_2003
P. 3
SEAWATER INTRUSION IN THE COASTAT AQUIFERS OF ITALY
Figure 1. Hydrogeological sketch-map of Italy. Arrows indicate first sector and is then characterized by sandy
deposits which form a major aquifer.
coastal aquifers endangered by saltwater intrusion.
Farther south along the coasts of Calabria,
Timavo. In the coastal areas of Friuli, Venetia the aquifers are hosted chiefly in a few small
and Romagna, rather complex multi-layered con- Recent alluvial deposits lying at the foot of hills
fined aquifer systems are hosted in the Recent and mountains along the valleys incised in the
alluvium deltaic plains of a number of rivers, the crystalline and metamorphic complexes of the
most important being the Tagliamento, Piave, Sila and Aspromonte. On the east coast, the Sibari
Adige and Po. alluvial plain represents the major aquifer region.
The land bordering the Apennines to the Proceeding northwards the coastal plains of
east may be divided into two sectors, one extend- Campania, Latium and Tuscany, bordering the
ing along the coast from the Marche to the Molise, Tyrrhenian Sea are composed chiefly of Quater-
and then continuing southwards into the Bradano nary deltaic alluvial deposits which form large,
trench between Puglia and Basilicata down to the well-replenished aquifers. In Liguria up to the
Gulf of Taranto, the other comprising the Apulian French border the major coastal aquifers are
regions of the Gargano, Murge, Tavoliere plain, found in the Mesozoic karstic limestones of the
and Salento peninsula. In the first sector, small marlstone, dolomite and calcarenite series of the
local aquifers are contained in sandy lenses Maritime and Ligurian Alps.
interbedded in Pliocene deposits of clay and mud,
many in contact with the Quaternary alluvium of In Sicily, in the entire north-eastern portion
the val1ey floors. The second sector consists of of the Province of Messina, small local aquifers
Cretaceous subhorizontal fissured and karstic occur in the fracture zones of the Caenozoic fly-
limestones which form excellent aquifer systems. sch and Palaeozoic metamorphic rocks and in the
The Tavoliere plain is connected to a strip of the alluvium of the valley floors. Along the north
coast of the island across the Province of Palermo
up to Trapani, the Mesozoic-Caenozoic series of
karstic calcareous highlands (Madonie, Imerese,
Panormidi, Trapanesi) host important aquifers. To
the west, in the Marsala zone, there are major
P1iocene-P1eistocene sandy-calcarenite aquifer
complexes. The Cretaceous-Miocene limestone
formation Hyblean plateau, rising in the south-
eastern part of the island, contains major and
well-replenished groundwater resources. To the
east, the sandy-clayey Quaternary alluvial
deposits of the Catania plain host a small aquifer,
where in many places groundwater floats on top
of saltwater. Between the Catania plain and the
Nebrodi mountains, Etna, the highest vo1cano in
Europe (3340 m) with its vast outcrops spread
over 1300 square kilometres, hosts Sicily’s largest
aquifers. Off the coasts of Sicily the volcanic
rocks of the islands of Eo1ie, Pantel1eria and
Ustica, and the calcareous rock of the Egadi and
Lampedusa islands, constitute very poor aquifers,
with insufficient yield to meet local demand
(Aureli, 1991).
209
