They will be the trunks on which it stands

Venice today is an amusement park. It has some of the most beautiful buildings in Europe and is a World Heritage Site, but waves of tourists also come for the other great tourist attraction: its canals. The city has become so romanticized that it practically lives on tourism and a tragedy like the COVID-19 pandemic was a complete devastation. This symbiosis with tourism is a love/hate relationship, but most importantly, it can be something that destroys the city itself.

This is because Venice is built on a forest of millions of trunks that have been kept in perfect condition for hundreds of years. A forest that we are endangering.

run to the islands, Today’s Venice is built on an archipelago of 118 islands that are interconnected by 455 bridges. It is an impressive network and wandering its streets is truly special. It doesn’t seem like the best place to build a city, but we can say that the first settlers had no other choice. The city was founded in the 5th century on a site that provided special protection against attacks from the Germanic peoples.

At first it was a lagoon with access to the Adriatic Sea and inhabited by fishermen, but well, it was an enclave with ideal characteristics to resist attacks and this is where those attacks caused those who fled from the surrounding cities. People had simply become barbarians. Everyone had to go ashore, so they began to expand the city and, as always, they began to take over the sea.

Wealth, When we build a building, we lay its foundation on the ground. They are important because they support construction, but the problem with Venice is that there was no land to build on, but only clay. It was not possible to evacuate all this and, obviously, not lay a brick foundation, so they began to cut down millions of trees in the surrounding area in order to lay the foundation of the city and build piles in the 9th century.

These are wooden pillars that were dug into unstable (clay) soil with a height of several meters to reach a layer resistant enough to hold these piles. The entire lot was submerged in water and buildings began to be built at the shallowest end. If we went to Venice the only wood we would actually see would be the poles to which boats are tied.

Wait, wood in water? Now the question is…doesn’t it rot? In nature, living trees and wood get along well with each other and can be semi-submerged. However, when the tree dies, if it comes in contact with water, it begins to rot. This happens because organisms (xylophages) come and start eating it. However, if we keep the wood completely submerged in water, those xylophages do not start doing their work.

This is because organisms that eat wood need oxygen and yes, there is oxygen in water, but it is not enough for these organisms, so the wood remains intact. This is more than a theory, as some accidents in Venice revealed after a few years that the piles were, in fact, intact.

good wood, As we mentioned, the wood to build the city’s foundation was extracted from nearby oak and oak forests. They are a type of wood that has natural resistance to xylophage, but at the same time they have very good properties to serve as a foundation and carry heavy weights. The salt water has gradually hardened the stems, so that they now look more like rock than wood.

Venice understood the importance of wood to its survival. They used it not only to gain land in the lagoon, but also to build the fleet of their important naval branch. The ships were important to the city for both its defense and trade, so a program was established to control the timing of felling, reforestation and the quality of trees (as we say, trees) used in buildings and trees. ) was banned for use in making firewood. Indeed, there is wood not only beneath the city, but also in large quantities in the structures of the main buildings.

agreement, Going back to piles, one thing that happens with any building is that it has a period of settlement. This is something that happens in any city and gradually and due to the weight of the building itself causes the city to sink. Let’s say it settles on the ground and this is something that affects many areas regardless of the quality of the soil, but in some it is a more serious problem. For example, in China we’re seeing big cities sinking because the bedding is supporting too much weight, and there’s a festival in Venice.

Because the bed is still clayey and soft, no matter how hard the piles are pushed into the bed, settlement occurs. And the result is buildings with displacements of several centimeters. In fact, interestingly, many of them have not collapsed (although, as we said, there have been accidents throughout history).

tide and rescue, This city is a marvel of engineering, but floods occur here from time to time. This is known as the Acqua Alta and is basically the rising tide between autumn and spring. When the water exceeds a certain level, a large part of the city is flooded, one of the most common points being St. Mark’s Square. This is a very popular event among tourists, who take photos and walk through the high streets, but it is a real problem for the city.

It is estimated that these investigations cost the city about five and a half million euros per year in lost hours lost (because shops cannot open), but this also has an impact on properties. Therefore, the MOSE system was released in 2020. These are huge defenses (dams) arranged at the main junctions between the Adriatic and the lagoon which are raised when necessary so that floods do not affect the city much. They are defenses that cost approximately 7,000 million euros and, according to those responsible, have worked adequately since they were installed.

Climate change and travel, This settlement of the city causes the city to sink between 2 and 4 centimeters every century, but this is something that can be accelerated. There are two main problems here: climate change and tourism. Melting of the poles threatens all coastal cities, but in a sensitive city like Venice it could be devastating. Furthermore, tourism is something that is disturbing the bed of the city as well.

It is not that Venice is sinking because of the millions of annual tourists, but because of the activity of cruise ships and other ships. The roads are canals and boats have been running for years, but currently there are boats of all types (police boats, typical tourist gondola, private boats and even delivery boats). These vehicles also include cruise ships, which pass within a few meters of the city, leaving impressive images, but also stirring up the sea floor and disturbing the soft soil that is part of the city’s foundation. So much so that they stopped them from coming to a certain distance.

Venice, you are not special, All this makes Venice a special city, but like this Italian wonder, stilts have been used all over the world. In some areas many cities are built on stilts, but these usually stick out, so they have deteriorated significantly due to attacks by xylophagy. However, two other cities that exemplify the use of piles are Amsterdam or Mexico City. Furthermore, buildings like the London Bridge, St. Isaac’s Cathedral in St. Petersburg or the Brooklyn Bridge in New York, Notre Dame in Paris or the Toledo in Madrid are built on wooden piles.

Images | Science Channel, Paolo da Reggio, Slice Science, Didier Descouens

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