Busy Schiphol airport designed a crazy labyrinth to cut ambient noise from arriving and departing planes
Unless Jack Torrance is chasing you through the Overlook Hotel's hedge maze, you might not put a lot of thought into landscape design. But when the officials at Amsterdam's Schiphol Airport were looking for a solution to their noise problem, they took inspiration not from traditional sound barriers, but from the way local farmers plowed their fields. Schiphol is the 4th busiest airport in Europe with up to 1,600 flights that arrive and depart each day. That amount of traffic has the potential to create a tremendous amount of unavoidable low-frequency ground noise, which led to an increasing number of complaints from the surrounding neighborhoods (although Chicago's O'Hare airport has to be the all-time leader when it comes to cranky neighbors).
The construction of Polderbaan, the airport's newest, longest runway only added to the tension – and the decibel level – so the airport called in the Netherlands Organization for Applied Scientific Research (TNO) to study the noise levels and to help design a solution. As Smithsonian magazine explains, vertical retaining walls like those that line both sides of busy freeways don't work for airport noise, because the sound waves themselves can "skip over" that kind of barrier. The researchers soon discovered that the ambient noise decreased in the fall when the farmers plowed their fields, because the furrows and ridges that were created in the land worked to deflect the sound waves instead of allowing them to travel freely across a smooth surface. That gave them an idea, one that was perfected by a team of landscape architects and land artist (yes, that's a thing) Paul de Kort.
De Kort drew from the acoustic discoveries of scientist-slash-musician Ernst Chladni and historical farming techniques in the region to design an 89 acre park that was enhanced by 150 man-made ridges that were spaced 36 feet apart and measured ten feet from the bottom of the trough to the top of each triangular ridge. The distance between them, the Landscape Journal explains, was roughly equivalent to the wavelength of the most prevalent sounds from the airport. He also built bike paths throughout the park, so that its pleasantly flat acreage could be used as something more than a lush, green sound barrier.
Buitenschot, as the park is known, was completed in 2013 and, in addition to being beautiful to look at, it has also proven to be more-than effective, cutting the decibel levels from Schiphol's ground noise in half. Last year, airport officials set up 35 noise monitoring points at various points around the property and discovered that, in every location, the sound levels were less than what the airport's neighbors required. For de Kort, the only downside is that Schipol's arriving and departing passengers won't necessarily notice his handiwork. "The ground sound spreads behind the plane that’s taking off, so in fact you fly away in the other direction,” he told Smithsonian Magazine. “You won’t be able to actually see the area from the air."