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Venice, its Lagoon, the Monster-MoSE

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Venice, its Lagoon, the Monster-MoSE
Venice, the Water, the MO(n)S(t)E(r)
We will speak about Mo. S. E.: that means Modulo Sperimentale
Elettrostatico, Elettrostatic Experimental Module.
For unterstand what it is, why thy want it, what it can do, you must
remind the very particular relationships that binds Venice to its waters
What you see today (the canals and the bridges in the streets, the boats
that brings marchandises and firewards, poeple in the water-buses and
in the water taxis and tourists in gondolas), all that remembers us the
birth of Venice: many many years ago, between the VIIth and the Xth
century…
What you see today (the canals and the bridges in
the streets, the boats that brings marchandises
and firewards, poeple in the water-buses and in
the water taxis and tourists in gondolas), all that
remembers us the birth of Venice: many many
years ago, between the VIIth and the Xth
century…
Venice and the Water
Venice and its lagoon today
Venice and its lagoon, how they are today, in a map
The lagoon today,
from the space
The lagoon today, seen by nearest
Look at the complexity of the tissue of canali, rii,
ghebi, barene…
The rivers brought sweet
water and sand
The mainland, the
rivers and the
lagoon, in a map of
1709 (Antonio Vestri)
The sand accumulated where the rivers joined the sea
A map of XVI Century (Cristoforo Sabbadino). Just at
the South you see the banks of sand accumuleted by
the cintrast between rivers flow and seaa streams
The two destinies of a lagoon
d’une lagune
The flow of the rivers brings the sand, the streames of
the sea rubble the coast
If the rivers prevails, the lagoon becomes a marsh, the
marsh becomes a solid field
If the sea prevails, the lagoon becomes a bay
The surviving of the lagoon depends from the
continous work of daily active maintenance of
the balance between the waters and the earths
8
The first settlements in the lagoon
The first settlements were fisherman villages on muddy islets
A city appears: Venice
The more ancient plan
of Venice (“Cronologia
Magna” from Paolino
da Venezia, 1346)
Venice in a map of
1557 (Cristoforo
Sabbadino)
Hunt in the
lagoon, in a
painting of
Carpaccio
Today landscape: lagoon and flowers
Today landscape: lagoon and fishermen nets
Today landscape: lagoon and industry
Today landscape: lagoon boats and modern boats
Today landscape: lagoon and peaceful hours
The high tide of 1966
In November 1966 pounding rain and an exceptional wind-swept tide flooded
nearly all the city streets for 24 hours. The storm focused world attention on
Venice. The reason? Venice had 'sunk'
New great events
1.
The fall of the Venetian Republic, at the
end of XVIII Ceintury, crushed between
the Empires of France and Austria
2.
The new techniques and the new
conception thad were affirmed in the
field of changing the phisical reality
19
New conception and new praxis
New
b conception and new praxis about the relationship
between développement and environment
•
The ancient civilasations (particularly the
Venetian one) considered the environment
as a resource that community was engaged
to preserve so to be used also in the future
•
The actual civilisation considers the earth as
a great neutral extension on which the
techniques can apport every
transformation, without any bad
consequences
20
Why was Venice
invaded from the water?
1. Since the early 1920s mainland factories have tapped
underground freshwater, depressing the land under Venice
in the process.
Pumping was finally stopped in the 1970s Venice had sunk
by about 12 centimeters (almost five inches) – a small but
important altitude change for a sea-level city.
2. Deep shipping channels were dredged through the
lagoon’s three inlets to transport raw materials – including
crude oil. The deeper channels brought stronger currents,
speeding the Adriatic’s high tides towards Venice,
exacerbating flooding and eroding the lagoon’s salt
marshes.
3. And, the final nail, the northern Adriatic has risen by
about 10 centimetres over the past century.
21
Changements in the Lagoon in the last century
The parts of the lagunar bassin closed to the
fluxes of tude for the industrial zones and the
agricolture, and the canals as highways
Changements in the Lagoon in the last century
The parts of the lagunar bassin closed to
the fluxes of tude for the “Valli da pesca”
Look once again at the Lagoon today
Who decides in fact what to do
After a long trip a new organisation was constituted: the
Consorzio Venezia Nuovo (the New Venice Consortium). The
Italian government set up the Consortium 20 years ago as an
‘exclusive concessionaire’, with a mandate to safeguard Venice,
and unite private and state-owned companies vying for what
promised to be fat public works contracts to protect the city.
As exclusive concessionaire the consortium holds a monopoly
on state-funded work to ‘save’ Venice and protect its lagoon.
This covers everything from strategic planning to research,
project design and construction. And since 1984 the Italian
government has provided the consortium with € 3.2 million to
study the lagoon’s ecology and hydrology, rebuild sea walls
along the lagoon’s barrier islands, restore salt marshes and
much more besides. All without any competitive bidding.
Behind the consortium (holding 40 per cent of its shares), is
Impregilo spa – a Milan-based construction giant that builds
dams, highways and power plants in over 40 countries.
25
Look at the MoSE project
This images are taken from a dépliant of Consorzio
Venezia Nuova
On the left you see the Lagoon of Venice and the
three outlkets, where sea water and lagoon water
exchange every 6 hours.
On the right the works prewiew in the three outlets
Il sistema del Mo.S.E.
To stop the flooding, Consorzio
Venezia Nuovo (the New Venice
Consortium) has proposed a
gigantic dam system: a line of
78 huge metal containers –
each at least 20 by 20 metres
in size – nestled in underwater
foundations stretching across
the three inlets between the
Adriatic and the lagoon (each
inlet is up to half a kilometre
wide). For most of the time the
hollow containers would be
filled with water. To stop a
storm surge from the Adriatic,
air would be pumped into the
containers – causing them to
rise like enormous teeth across
the inlets.
You see the elements in the
three standard positions
The outlet of Malamocco
Si osservi, a
partire da
sinistra, la nuova
conca di
navigazione, che
dovrebbe
consentire
l’accesso alle navi
quando le paratie
sono sollevate (in
giallo)
Look yhe big works in the inlets in the central
part of the lagoon, leading to the Oil Cjannel
Schemes
I 10 più alti livelli
dal 1920:
11.2002:
11.2000:
12.1992:
02.1986:
11.1979:
01.1979:
11.1968:
11.1966:
10.1960:
11.1951:
147
144
142
159
166
140
144
194
145
151
Le fasi della marea
sono di sei ore:
quindi due volte al
giorno l’acqua
“entra” e altrettanto
“esce”.
Le acque alte
superiori a 110 cm
sono state,
nell’ultimo mezzo
secolo, da meno di
20 a più di 50
all’anno.
I tre schemi illustrano tre
situazioni differenti in
relazione a diverse situazioni
del dislivello tra altezza
dell’acqua e quota del suolo.
L’altezza esprime il livello
raggiunto dalla mariea rispetto
alla media (livello medio mare
= l.m.m.). I pavimenti di
Venezia variano da un’altezza
di circa 60 cm (la zona di
Piazza San Marco) a quasi 200
cm.
Il progetto complessivo
prevede che tutto il suolo
pubblico venga gradualmente
portato ad almeno 110 cm sul
l.m.m. (ma prevalentemente a
cm. 130). La chiusura delle
Bocche di porto dovrebbe
avvenire quando l marea
supera questo livello.
Why not
1 The proposed dams failed their official environmental impact review in 1998.
2 The consortium wants to dredge about five million cubic metres of the lagoon’s
bed and dump almost eight million tons of rock and 700,000 tons of concrete in its
place.
3 During long closures the dams could bottle up industrial and agricultural pollution
in the lagoon, which is now flushed by the regular tides. The city also lacks modern
sewage treatment.
4 Anodes to protect the metal gates from sea-water corrosion would release over
10 tons of zinc into the lagoon a year. The toxic metal could accumulate in the food
chain.
5 The consortium’s project ignores a fundamental cause of flooding in Venice – the
deep shipping channels through the lagoon’s inlets. The consortium wants to open
them even further, replacing their current V shapes with straight cuts across the
full width of each inlet.
6 The dams would be expensive to build. The consortium estimates total costs at
about 7-8.000 million Euros, but critics warn that the untest system could cost far
more.
7 After construction, the Consortium could then reap millions of dollars a year for
their operation and maintenance. These costs are also extremely difficult to
estimate, as the underwater structure would face ongoing corrosion and
encrustation and would require extensive maintenance.
8 The dams may not even protect Venice from flooding.
30
An alternative way
The primary aim is the re-equilibration of the complex system
of the lagoon, by acting on the whole set of elements that
compose it. For the emergency, this action can be done:
1. Reducing the depth, width and wind exposure of the
Lagoon's three outlets to the sea. By eliminating the
majority of flooding events.
2 Complete work to raise the lowest parts of the city to
+110 cm above the mean sea level mark, high-water flooding
events would occur an average of less than 4 times a year, in
most cases for only a small part of the city.
Together, these two types of actions would reduce current
flooding events to an average of only once every five years.
3 Removing oil tanker traffic from the Lagoon - as
specified under Italy's 1973 special law for Venice - and
building a dock along the Lido, outside the Lagoon, for the
largest cruise ships.
31
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