Warming seas and excavations within the Venice lagoon mean the exceptionally high flood waters in the city this week are also saltier, posing an extra threat to its architectural treasures, Trend reports citing Reuters.
When the water recedes from the cobbled lanes, marbled palaces and ancient churches of a city that rose up out of marshes 15 centuries ago it leaves salt crystals which slowly corrode the brickwork and will eventually eat it away.
“With the salt water everything becomes more difficult for us,” Mayor Luigi Brugnaro said on Friday as a fresh inundation left 70% of Venice submerged just three days after it suffered the worst floods in more than 50 years.
The lagoon has always held a mixture of water from rivers which feed it and that which enters via openings to the sea. Rising sea levels brought about by climate change and the digging of new canals and other structures mean more salt water is coming in from the Adriatic.
In the 1960s, a canal was dug in the lagoon for oil tankers to reach the petrochemical plant of Marghera, a port less than 5 km (3 miles) from the old center of Venice.
More recently, moon-shaped piers built to protect the gaps of the Venice lagoon were reckoned by the scientists of the National Center for Research (CNR) to have created big depressions in the sea bed, which would also allow more sea water in.