The Problem Today, Venice’s economy largely depends on the millions of tourists that flock there every year. Tey come to view the magnificent architecture and walk through the historic squares, or piazzas. Or they explore the canals in gondolas, specially designed boats that can easily navigate the narrow canals. To Italians and tourists alike, Venice is one of the world’s great cities, a symbol of grandeur, and permanence. However, there is a problem. Te sea that has been so important to Venice’s history now threatens the city’s existence. Troughout history, the sea has been a
constant benefit and hindrance to Venice. Tidal waters from the Adriatic surge into and out of the lagoon daily. Tis regular flushing of the canals keeps the water clean by acting as a natural sewer system. Ocean-going ships use the deep waters of the high tides to get close to the city so they can dock and exchange goods. Yet these regular tides also threaten the very foundations of the city.
About 50 times a year, tides are high enough
that seawater washes over the lowest-lying parts of the city, including the famous Piazza San Marco. Venetians take these frequent floods in stride. Tey pull on their wading boots and slosh through the floodwaters where they must. Tey use temporary elevated walkways where they can. Occasionally, the floods become more than
just a nuisance. Rain and strong winds combine with high tides to flood parts of the city with more than a meter of water. Salt in the seawater eats away at the stone foundations and brick walls of the historic buildings.
Frequent Floods Te frequency of flooding in Venice has increased in recent decades. One reason for this is that the foundations of buildings in Venice have been slowly settling since they were first built. Aſter all, the city is built on soſt clay and compacted mud that forms the bottom of the lagoon. Evidence shows that Venice has sunk about 13 centimeters every century. Sometimes, people’s actions have hurried the process. In the 1950s and 1960s, groundwater was pumped out from beneath the city for industrial use. Te weight of the city pushed down to fill the space, and Venice sank more than 11 centimeters in that short time. Rising sea levels impact Venice, too. Sea
levels around the world are rising, mostly because of global warming. Te warmer temperatures melt more of the polar ice caps which causes sea levels to rise. Warmer temperatures also make water expand—the water molecules move a little farther apart from one another, so the water takes up more space. Te increase in sea levels has resulted in higher tides and deeper floods. A sinking city and rising sea levels mean
that high tides pack a bigger punch. Engineers began to investigate a way to keep the flow of water from damaging or even destroying the city. A few years ago they came up with a possible solution.
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