Azernews.Az

by Alimat Aliyeva

Existing flood defenses in Venice will only be able to protect the city from rising sea levels for a limited time. In the long run, authorities may need to consider more drastic measures — including the partial relocation of parts of the city inland, AzerNEWS reports.

This conclusion comes from a study led by Piero Lionello of the University of Salento, whose team analyzed how resilient the Venetian lagoon barrier system is to long-term sea level rise.

At present, Venice’s primary line of defense is the MOSE system — a network of mobile barriers installed at the three inlets of the lagoon. Researchers estimate that even with upgrades, these defenses may remain effective only until sea levels rise by around 1.2 meters. Beyond that threshold, the city will likely need to adopt a completely new adaptation strategy.

The study outlines four possible scenarios: further enhancement of the existing barrier system, construction of ring-shaped dams around the historic center, transformation of the lagoon into a fully enclosed basin, or the gradual abandonment of certain areas combined with the relocation of key cultural assets.

If sea levels rise by about 0.5 meters, building circular dams around central Venice could become necessary. While this would help protect the historic core and nearby islands, it would also require large-scale pumping systems and significantly alter the city’s transport and tourism infrastructure. Estimated costs range from $540 million to $4.9 billion.

A more radical option involves creating a fully enclosed lagoon with permanent barriers and external protective structures. This approach could safeguard the city from much higher water levels, but it would likely devastate the lagoon’s delicate ecosystem. The projected cost of such a project could exceed $32 billion.

In an extreme scenario — with sea levels rising by more than 4.5 meters — scientists are even considering the partial relocation of Venice inland. This would involve moving cultural monuments and abandoning parts of the historic urban landscape, with estimated costs reaching up to $108 billion.

According to Robert Nicholls of the University of East Anglia, there is no perfect solution for Venice. Efforts to protect cultural heritage, housing, jobs, and the natural environment inevitably come into conflict.

Researchers stress that Venice is not an isolated case. Many low-lying coastal cities around the world face similar long-term risks. What makes Venice unique, however, is its extraordinary cultural value — which turns the fight against rising seas into not just an engineering challenge, but a global effort to preserve one of humanity’s most iconic urban landscapes.