Ridge and furrow
By George Bull
It is difficult to imagine that any park landscape could owe its existence to the annoying low-frequency drone emitted by aircraft during take off. So it’s with some confidence that Buitenschot Land Art Park at Schiphol airport in Amsterdam can claim to be a world first. Officially opened in October 2013 and set on 36 hectares of land south of Schiphol’s longest runway, Buitenschot is a bold experiment in how we choose to address problems associated with airport infrastructure. Here, meticulous but simple landforms create a landscape that not only serves a specific function but is also an intriguing public space.
Amsterdam Airport Schiphol is Europe’s fourth busiest airport. The outlying site of runway 18R-36L, or the Polderbaan as it’s more commonly known, was originally intended to reduce the overall noise disturbance by redirecting air traffic over areas with a lower population density. Instead, it created another problem: ground-level noise. This led to years of complaints from residents in surrounding urban areas such as Hoofddorp, unable to block out this low-level din produced every time an aircraft left the runway. This type of noise is also exacerbated by the Haarlemmermeer landscape upon which the Polderbaan is built. Flanked on one side by the Geniedijk, part of the Stelling of Amsterdam dike system, it was once the bed of a huge lake; flat and featureless, there has been nothing to disrupt the path of the sound waves – until now.
At first glance then, Buitenschot stands out from the flat expanse of the Haarlemmermeer polder like some sort of alien sculpture. But its geometric structure of long parallel ridges and deep furrows is rooted in the area’s agricultural heritage. Having reached an agreement with Hoofddorp Noord residents’ association that it would reduce ground-level noise by 10 decibels, Schiphol Group set about trying to solve the problem. After a 2008 competition failed to produce a viable solution, the answer presented itself with the changing of the seasons. It was autumn and the land between the runway and the surrounding settlements, which is nearly all arable, had been ploughed. And there was less noise.
The realisation that the silence had something to do with the ridges and furrows created by ploughing provided the impetus for Schiphol Group, Stichting Mainport en Groen (a foundation that invests in green and recreational facilities around Schiphol airport) and the city of Haarlemmermeer to investigate further. They commissioned TNO (the Netherlands Organisation for Applied Scientific Research) to carry out a technical study of how effective a ploughed field could really be at reducing ground-level noise, and asked H+N+S Landscape Architects to think about a land-use strategy that might recreate the same conditions.
H+N+S is no stranger to real design challenges – its 1985 spatial strategy Plan Ooievaar is regarded alongside the Casco-concept as a milestone in involving landscape architects in the design of water and land at the regional scale. Determined to come up with an idea that had a precise relationship with the landscape, H+N+S director Lodewijk van Nieuwenhuijze says the practice first engaged an agricultural specialist to see if small, durable dunes could be created by cropping a perennial vegetable such as asparagus. When this approach was shelved owing to problems with the amount of kerosene the crops would be exposed to, he worked with TNO on developing a series of huge ridge structures that would not simply emulate but would actually enhance the noise-reducing quality of a parcel of ploughed land.
Confronted by these solid structures, ground-level noise crumbles in the spaces between the furrows. Each ridge has sharp edges and measures 3m from the lowest to the highest point. The ridges are 11m apart.
‘We tested a 1:1 model in the landscape and it worked even better than in TNO’s technical model,’ explains Van Nieuwenhuijze. ‘The idea was that the ridges would then be laid out on several different land parcels between the runway and the surrounding urban area to achieve the 10 decibel reduction.’
With a working landscape strategy in place, an initial area of 36 hectares was agreed for the project – enough to deliver a reduction of two to three decibels out of the overall target – but it wouldn’t fully take shape until the arrival of land artist Paul de Kort. ‘We are always trying to invent new ways for landscape architects to work,’ says Van Nieuwenhuijze of the collaboration with de Kort, whose plan to create a symbiosis between the purely functional horizontal ridges and a pleasant environment would become Buitenschot Land Art Park.
De Kort’s vision for Buitenschot comes from 17th-century Chladni patterns, which involve strewing sand or salt across a metal plate and then brushing a fiddlestick along it to sound a keynote. ‘The vibrations cause the sand on the plate to jump up and fall back down in beautiful geometrical shapes, so that sounds became visible,’ he explains. ‘The ridges have a mutual distance that is almost equal to the wavelength of ground-level noise. So you could consider these ridges, with just a bit of poetical inspiration, as materialised ground sounds.’
The pattern that the ridges assume on the ground is also part of de Kort’s design. Inspired by Haarlemmermeer’s watery past and the angle at which the Geniedijk cuts through this strict grid of reclaimed land, he envisioned the ridges as waves turning towards a beach before fading out. To create this effect, a second layer of ridges is rotated at 18° with respect to those ridges running parallel to the structure of the polder. The result is an exciting, meandering landscape – and because this second layer is perpendicular to the direction of the noise, it helps further combat it. De Kort also pushed for some alterations that simply enhanced the aesthetic: he was determined, for example, that the ridges run to a pointed end in order to make the landscape more fluent, despite being more expensive to create and adding little to the ridges’ noise-reducing qualities.
De Kort’s influence has been to make the story of the landscape legible – to humanise it for the residents of Hoofddorp and Vijfhuizen. The shift in the angle of the ridges, and their height, lends Buitenschot a maze-like quality, which makes people slightly disorientated. ‘The surrounding landscape of the Haarlemmermeer is so overwhelmingly large and wide, and there is always a strong wind, it seemed right to me to create spaces of a certain intimacy and seclusion within these surroundings,’ he says. Sheltered glades and smaller and larger ‘rooms’ within the landscape structure invite people to play sports, games, or simply relax. A paved bike path connects the Geniedijk to the outlying country road, while a system of mown paths provides an informal network in and around the ridges, whose soil walls are sown with slow-growing red fescue.
‘Chaldnipond’ is one of two artworks de Kort designed for the site. Halfway across this diamond-shaped pond is a bridge with a mechanism underneath it with which you can create waves in the water. ‘The reflections of these waves against the straight riverbanks brings the design of the entire land art park into mind,’ he explains. The other artwork comprises the ‘Listening Ears’, inspired by parabolic devices once used on the English coast to listen out for incoming enemy aircraft. These two 3.5-metre steel dishes invite people to stand inside them whereupon they amplify sound coming from far away.
Buitenschot represents an investment of some 3 million Euro from Schiphol Group and Stichting Mainport en Groen, and despite praise for the project’s unique approach, it has not escaped criticism. There has been consistent opposition from some of the local farming community, for example, for whom the project has meant refashioning land used for crops. The park’s success is therefore crucial to the organisations’ long-term aspirations to extend the scheme over 60 hectares in order to reach the agreed noise reduction target of 10 decibels.
For Van Nieuwenhuijze, the project also has scope beyond the Netherlands. ‘We are trying to convince Schiphol to put this project on an international platform. In the US and even in the UK, for example, there are a lot of airports in urbanised areas and this is a way of reducing noise while putting quality back into the neighbourhood. I hope we can make this idea work in more places.’
George Bull is a former editor of Landscape.