Presentation on theme: "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."— Presentation transcript:
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…
Venice and the Water 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 its lagoon today Venice and its lagoon, how they are today, in a map
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
8 The two destinies of a lagoon dune 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
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)
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'
19 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
20 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 b New conception and new praxis New conception and new praxis about the relationship between développement and environment
21 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 lagoons three inlets to transport raw materials – including crude oil. The deeper channels brought stronger currents, speeding the Adriatics high tides towards Venice, exacerbating flooding and eroding the lagoons salt marshes. 3. And, the final nail, the northern Adriatic has risen by about 10 centimetres over the past century.
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
25 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 lagoons ecology and hydrology, rebuild sea walls along the lagoons 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.
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 laccesso 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 tre schemi illustrano tre situazioni differenti in relazione a diverse situazioni del dislivello tra altezza dellacqua e quota del suolo. Laltezza esprime il livello raggiunto dalla mariea rispetto alla media (livello medio mare = l.m.m.). I pavimenti di Venezia variano da unaltezza 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. I 10 più alti livelli dal 1920: 11.2002: 147 11.2000: 144 12.1992: 142 02.1986: 159 11.1979: 166 01.1979: 140 11.1968: 144 11.1966: 194 10.1960: 145 11.1951: 151 Le fasi della marea sono di sei ore: quindi due volte al giorno lacqua entra e altrettanto esce. Le acque alte superiori a 110 cm sono state, nellultimo mezzo secolo, da meno di 20 a più di 50 allanno.
30 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 lagoons 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 consortiums project ignores a fundamental cause of flooding in Venice – the deep shipping channels through the lagoons 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.
31 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.