According to the author of a new paper published in the journal, when a tsunami descends to the shore, a hilly park can be as protected as a towering breakwater. National Academy of Sciences.
This tsunami mitigation park is designed to combine the so-called protection quality of an engineering environment with the benefits of a more natural environment. The hybrid approach is particularly attractive for low-rich countries looking for alternatives to expensive barriers that preserve coastal economies and lifestyles.
“Anything can be built up. Dogs and walls can be stacked. Jenny Suckale, assistant professor of geophysics at Stanford University, says: “The wall doesn't have to understand what you really want to protect. But this coastal relaxation park Do; They are actually targeting the main problem. ”
The main problem the park solves is not the water itself, but the enormous amount of energy that water carries to the tsunami, Suckale says. Earthquakes, volcanic eruptions, and moving along the seabed can cause tsunamis, which can release enormous amounts of energy. That's why tsunamis with 1-foot-high waves can cause devastating damage.
“Water will hit you,” said Suckale. "The reason you die is because you fall and the water is so fast that you throw all these things at you."
Breakwaters can block some of that energy, but tend to block people's access to water. When a tsunami occurs, the wall breaks into debris and strikes the community with waves. The tsunami mitigation park is an alternative to breakwaters and is being developed in Chile, Indonesia and Japan. This new park has not yet had to go through the tsunami, and researchers were interested in how well they could withstand the wall.
Suckale and colleagues used computer models to understand how the tsunami park, which occurs when a tsunami wave hits a row of hills, can work during a tsunami and what you can do to improve your design. They found that hills partially deflect waves and can reduce the amount of kinetic energy that water brings to the land for tsunamis that are not much larger than the hills themselves. They found that the hills could provide a level of protection similar to that of a breakwater, and the design of adding breakwaters to such hills does not provide much additional defense. The combination of this wall and hill has been adopted in Chile's Constitución and Miyagi Prefecture in Japan recently, and the tsunami has caused tsunami damage in both places over the past decade.
The study also found that most of the defenses provided by Palliative Park come from the land itself, not from vegetation planted to dissipate the power of the waves. Pines and eucalyptus trees are planted in Constitución as part of the city's efforts to prevent tsunami damage in 2010. The budge. However, vegetation can prevent the waves from falling off the hill.
However, there are some risks in a poorly designed tsunami mitigation park. Rolling hills can actually strengthen the flow of water between them, causing more destruction behind the hills. Instead, the rows of staggering hills where the buffer zone is located just behind it, which grows smaller inland, can reduce the risk of concentrated water flow.
“There is a right and wrong way. Suckale says that it can actually make things worse, similar to how the walls can collapse and cause additional damage. She added that it is important to customize the park design for each coastline.
Ultimately, according to Suckale, mitigation parks can effectively push communities away from the much safer shores, but still have access to water to make a living or enjoy the shores. She also said that it is best to evacuate to high places when there is not enough time to flee inland, so she provides a place for residents to find refuge on the hills during the tsunami.
Breakwaters are still a common way many coastal communities try to protect themselves from tsunamis. Japan has invested more than $ 12 billion in the 245-mile breakwater since the earthquake and tsunami in 2011, eventually causing another disaster with the collapse of the Fukushima Daiichi nuclear power plant. However, the wall was criticized by some professional fishermen. "We didn't do anything, but we feel like we are in prison," said Atsushi Fujisatsu, oyster fisherman. Reuters 2018.
Tsunami experts from countries like Indonesia and beyond, which suffered the most deadly tsunami recorded in 2004, hope that the mitigation park will provide greater protection and peace of mind to its residents. Suckale co-author Abdul Muhari leads the Coastal Disaster Relief Division of the Indonesian Ministry of Maritime Affairs and Fisheries. By email The budgeHe said, “We are [tsunami mitigation parks] Is too much in Indonesia [more] It can be realized in the near future. ”