[In the last two decades the once distinct disciplines of ‘defence’ and ‘security’ have merged, their previously clear-cut boundaries blurring. Actors other than nation states pose potentially existential threats; so, too, do ‘new’ threat axes, such as cyber attack and climate change. The will to defend against these new vectors frequently involves advanced technologies – and significant costs, deemed worth it to defend the selected ‘target’ community. But who knows where the technologies developed for such tasks may later be applied? MON correspondent Massimo Annati reports from Venice on one iteration of this modern phenomenon. – Editor]
For centuries the Serenissima Republic (Venice) ruled the Adriatic and Eastern Mediterranean, its galleys flying the red and gold winged lion of Saint Mark. Today the iconic city, sitting on a large lagoon, is one of the most famous and most patronized tourist destinations worldwide. It is, however, a very fragile environment, facing multiple threats, from air and water pollution to increasingly frequent flooding.
The latter is caused by the combination of unusually high tides with unfavorable winds, pushing the waves inside the lagoon and raising the water level. Images of Saint Mark’s Square covered in water, with people wading up to their knees and thighs, are enough to convey a sense of potentially catastrophic damage. In November, the highest tide in 50 years left 85% of Venice flooded.
Eventually, after 20 years of studies and small-scale prototypes, construction of the MOSE gate barrier began in 2003. The system is composed of four rows of gates at the three main inlets: large steel boxes, 20m wide,18-29m long and 3.5-5m high, are raised from their steel and concrete bottom structure using compressed air. In normal conditions they remain at rest at the bottom of the deep-water canals leading into the lagoon, enabling the free passage of shipping and the normal flow of tidal waters. Locks are also included for two of the three inlets, allowing operations for merchant vessels and fishing or leisure craft. The entire process is managed from a control centre at the Arsenal, where the Serenissima’s galleys were built and maintained.
The entire project will become operational by the end of 2021, nine years behind schedule. The total final price is €5.5 billion, compared to the original €3.5 billion budgeted in 2003. It faced fierce opposition from some environmental activists and ‘not in my backyard’ groups, with a number of interruptions caused by judicial battles, which were eventually won by the government.
Prime Minister Giuseppe Conte activated the entire gate barrier system during the first full test on 10 July this year. MOSE will be able to stop higher tides, from 1.1-3m. This means it should be able to protect the lagoon and the city even in the event of a general 60cm rise in sea level due to global warming.
Massimo Annati in Venice for MON