Venice, often called the “Floating City” was built on a series of more than 100 small islands in a lagoon in the Adriatic Sea. Twice every day the water in the lagoon drains away from the city’s 124 islands and fills up again with fresh seawater. This constant movement of water gives Venice its unique, ethereal character, but it also makes city maintenance a bear to handle. The city’s construction began in the 5th century AD after the fall of the Roman Empire and it was initially built as a refuge for people fleeing from invading barbarians.
Buildings in Venice are built over 10,000,000 close-together, 60ft-long, water-resistant tree trunks that were chopped down 500 years ago
The city’s unique geography required innovative engineering solutions to create stable foundations for its buildings. Wooden piles were driven into the marshy ground, far below the weak and unstable topsoil to a layer of harder clay below, which held the piles in place. Two horizontal layers of wood were then placed on top of the pilings, followed by a layer of limestone and then the buildings went on top of those. They placed a lot of these pilings down; for instance, the Rialto bridge is supported by somewhere in the region of 12,000 pilings.
The wood went through soft silt and dirt to a layer of hard clay that was strong enough to support buildings on top
As for the sinking, yes, Venice is indeed sinking, but the situation is more accurately described as subsidence. Subsidence is the gradual sinking or settling of the ground surface, and it’s a natural process in Venice due to a combination of factors, including the compaction of the underlying sediments, groundwater extraction, and the weight of the buildings on the wooden pilings. Additionally, Venice is experiencing relative sea-level rise due to global climate change, exacerbating the issue. Some experts warn that global warming will cause sea levels to rise and eventually cover the Adriatic coastline and the city of Venice by 2100.
Global warming might cause sea levels to rise and eventually cover the Adriatic coastline and the city of Venice by 2100
Each year, Venice sinks another 1-2mm. This, together with high tides (locally known as acqua alta) and erosion in the Lagoon, causes periodic flooding in the city
A view of Palace Flangini painted by Bellotto in 1741 (left), and a detail of the main entrance today (right). The algae shift is 71 ± 12 cm. The main staircase is now submersed and covered with algae.
