The Floating City?
By Hans del Cid
Guatemala City, Guatemala
This city truly defies human imagination. The floating city of Venice, Italy, is without a doubt one of those places you must visit. It has lavish buildings, such as Saint Mark’s Basilica, as well as 118 islands connected by more than 400 bridges surrounded by about 150 canals. You can also take an inspiring gondola ride through the canals of this romantic place.
Venice is located in the north of Italy, on the Adriatic Sea, and has a rich history. Probably one of the most common words in 2020 was “quarantine,” and it was in Venice where this word was used for the first time. In the 14th century, preventing the Black Death plague required new precautions.
Given its origins as a center of trade, large ships from various parts of the world came to Venice to market their products. And so Venice had to prevent disease outbreaks by putting them through a quarantena (“forty days”) before travelers could disembark.
While visiting Venice, you are probably going to ask yourself two questions:
- Why did they come to live on these islands?
- How could they build a whole city on swampy islands in the middle of the sea?
The answer to the first question is that the inhabitants of Veneto, a city on the mainland, found these marshy islands to be an excellent outpost to watch for approaching enemies. The Lombards, for example, invaded from the north and conquered the region during the late 6th century BCE. This strategic location allowed Veneto/Venice to form an independent republic that lasted from 697 to 1797. It was known as La Serenissima (“Most Serene”).
After losing a battle to the French army under Napoleon Bonaparte, Venice was traded back and forth between France and Austria for several decades. It wasn’t until 1866 that Venice became part of Italy.
How Venice Was Built
Now let’s figure out how Venice was built. For some reason (perhaps to preserve the magic?) not many people know that the city actually rests on millions of tree trunks. Can you imagine that?
The original inhabitants of Venice created an ingenious way to build. Since the swampy land was not able to support the weight of the buildings, they sank. So the Venetians devised a technique where they drove long wooden logs deep into the solid clay underneath the water. These pilings formed a strong base that now supports the weight of an entire city. The logs do not rot or decay, because the airless, muddy soil protects them. In fact, over time they have turned into stone! That is why the city has been standing since 421 CE.
Floating and Sinking
So it is probably correct to say that Venice is a floating city, but also that it is a city on trees. Unfortunately, in the last decades another nickname has been given to Venice: the sinking city. Scientists have found that Venice sinks 1-2 millimeters every year. Several factors contribute to this situation:
- the weight of the buildings
- groundwater pumping
- plate tectonics
- rising sea levels due to climate change
Venice was built from a swamp, became a key point for trade, and then developed into one of the most powerful cities in Europe. It’s incredible to think that it now struggles to survive. It faces dangers not only from natural events, but also because it depends exclusively on tourism for its economy. So when you visit Venice and sit down to eat a tiramisu, you will probably understand why it costs so much!
- Twelve students are visiting Venice to study the impact of global warming on the city. One evening, they take two gondolas to get to dinner. List every way the group of 12 can divide up to take the two gondolas. (Note: you can change this problem by changing the number of students.)
- Consider these 12 students again. How many unique ways can the students be divided so that each gondola has exactly six students?
- Venice has 118 islands and more than 400 bridges. On average, how many bridges connect each island? What is the minimum number of bridges an island must have? Imagine a city on three islands. Each island is connected to every other island by exactly one bridge. How many bridges are in the city? Now imagine three more cities. One with four islands, five islands and six islands. How many bridges will each of these cities contain? Do you see a pattern? How can you use this information to determine the number of bridges in a city with 100 islands?
- If Venice was founded in 421 CE, how old is Venice? How many centuries/decades has it been in existence? How long has Venice been an Italian city?
- About 262,000 people live in Venice. On average, how many people live on each island?
- Fritelle are a popular treat in Venice, especially during the holiday of Carnavale. A bakery made 20 fritelle one morning. By noon, only six were left. Receipts showed only three customers had ordered fritelle that morning. How many total fritelle did they order? Make a prediction about how many fritelle each of those three customers purchased.
Social Justice Question
Venice’s permanent residents are being driven out by high prices due to overtourism. The COVID-19 pandemic brought tourism to a halt, creating an opportunity to revitalize Venice as a place to live. If you were the mayor of Venice, would you create policies to preserve the city for residents? Or would you let it become a city that exists only for tourists?
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Photo Credit: Hans del Cid
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