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SEAWATER INTRUSION IN THE COASTAT AQUIFERS OF ITALY
a rate of 100 to 300 l/s, and 5 with a rate of 300 to Capri opposite, a number of springs (Castellam-
1000 l/s. The aggregate yield is estimated at about mare di Sorrento, Cava dei Tirreni) yield more
4 m3/s. The Murgia karstic tableland contains sig- than 50 l/s, but part of their flow is directly dis-
nificant groundwater resources, abundantly charged into the sea. The aquifers of the thick
recharged at various levels, and supplying many alluvial sediments, coastal sand dunes and
springs flowing along the coast or spilling direct- vo1canic tuffs, the most common in the locally
ly into the sea. The piezometric surface indicates marshy coastal plains of Tuscany, Latium and
a flow towards the Adriatic with a gradient of 0.1- Campania are abundantly recharged by lateral
0.3% and a less marked gradient towards the Gulf flow from the karstic aquifers and volcanic struc-
of Taranto. Springs are few, but some have signif- tures cropping out to the east, to the extent that
icant capacity: the aggregate yield of the Murgia large-scale land reclamation and drainage works
springs is 7 m3/s. On the Salentina Peninsula, had to be carried out. Spring outflow into the Pon-
consisting of stratified and very faulted karstic tine marshes, south of Rome, is estimated at about
calcareous rocks, there is a major groundwater 20 m3/s south. In the Campania plain estimated
reservoir with 80 logged springs yielding in total transmissivity ranges from 10-3 to 7x10-3 m2/s.
up to 10.4 m3/s. The gradient of the piezometric Actual outflow is significant and supplies more
surface 0.02%. than 5000 dug wells and boreholes.
Along the Ionian sea, ten or so valleys orig- In Tuscany, in the rugged and fractured cal-
inating in the Apennines of Lucania slope down careous heights of the Apuane Alps, famous for
into the Gulf of Taranto. Their alluvial deposits their marble quarries, intensive fracturing has
form the coastal plain of Metaponto, Scanzano assured an abundant flow of water be it of little
and Policoro, with alluvial aquifers of consider- local utility. Other isolated carbonate rock occur-
able importance even though they are less than rences, alternately rugged and smooth, cropping
100 metres thick and have poor permeability due out in the semi-permeable fields of flysch are
to interbedded clay. Groundwater development found in the marshlands between Grosseto and
there is quite limited. Orbetello,
In the multilayered confined aquifer of the The numerous more or less productive
Sibari plain, on the Calabrian side of the Gulf of springs in the prevalently karstic limestone
Taranto the piezometric surface generally tends areas of the Maritime and Ligurian Alps yield
seaward, with a gradient of 2% at the upper level an aggregate flow of 6 m3/s, partly discharged
and 0.1 to 0.2% by the coast. This indicates that into the sea.
the aquifer is drained by the Crati River and fed
by adjacent watercourses. Aquifer transmissivity In Sicily (Aureli, 1991) the complex aquifer
is in the range 5x10-2-10-3 m2/s (Aureli, 1991). system of Mount Etna (3340 m), the largest active
volcano in Europe, supplies 289 springs, and 38
Along the Tyrrhenian coast, the aquifers of drainage gal1eries of which 18 have average
local importance in the alluvial plains of the Cal- yields of 110 to 1000 l/s. The lava flows on the
abrian coast near the Straits of Messina, are over- east side of the volcano are in direct contact with
exploited by more than 6000 wells. Further north, the sea, where part of their groundwater is dis-
the coastal aquifers of S. Eufemia and Gioia, 30 charged. There are more than 1200 wide-diameter
to 100 metres thick, are on the other hand of wells and 189 boreholes, giving a total yield esti-
major importance to the local economy thanks to mated at 15 m3/s. Total capacity of the aquifer is
their large storage capacity, supplying more than estimated to be about 20-25 m3/s.
3500 springs .
Estimated transmissivity of the sedimentary
Between the Gulf of Naples and the Gulf of aquifer in the Catania Plain, largely supplied by
Salerno, in the Sorrento Peninsula, composed of lateral inflow from the Mount Etna volcanic rocks
carbonate rocks that also crop out in the isle of to the east, ranges from 2x10-3 to 10-4 m2/s. A total
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