Trees Cannot Drive Cars

Middagterallee in Dieren (G.Verschuure-Stuip, 2015)

During the last six month, the discussion on the cutting off trees next to Dutch N-roads, provincial roads, was intensified. It started as a ‘soft’ rule in the ‘Handboek Wegontwerp 2013’ which was published by the knowledge platform CROW, which stated that a tree should be planted away from the road for at least four and a half meters. But it escalated in a question list and discussion on ‘dangerous’ provincial roads by the ANWB (which actually was filled in by only a small group of its members). Many of these ‘dangerous’ roads are flanked by rows of old trees or these roads are in the midst of natural reserved areas. It was argumented that these roads and especially the trees next to it are leading to more injuries and deaths by car accidents. A group called ‘Knights of Trees’ (Bomenridders) collected –with success- many thousands of signatures of worried people, fearing the cutting of trees on large scale in the province of South Holland. But this fear is not over yet!

Cutting Trees a Solution?

No doubt that every death or traffic injury is one to many and this should be prevented. Traffic safety is of great importance to us all. But the question rises if downing rows of trees, even 200 or 300 years old trees, is the solution? Of course, it is very pitiful when a car loses control and crashes against a tree. But what would be the consequences if, because all trees in the middle of the road (parkway) were cut off, a troubled car is ending up at the other side of the road facing the oncoming vehicles? What would happen if a group of biking youngsters on the biking lane next to the road would be driven over because of the lack of a row of trees to safeguard them? Is it not the displacement of another problem? Is the basis of the traffic problems this long row of beautiful trees or do we need to take a closer look at specific, dangerous spots? And is the tree, which is standing on the same spot in all cases the most guilty party or do other factors, not at the least the way people drive, play a much more decisive role? The research of the ANWB didn’t answered all of these questions in their story.

The beauty of a avenue flanked with trees. Fonteinenallee in Renkum (G.Verschuure-Stuip, 2015)

Ecology and Environmental Issues

Traffic safety is one of the users arguments. But there are many more arguments not to cut off trees, which should be taken into account every time when is decided if a tree should be cut off or not. First and foremost, trees play a crucial role in the ecology and environmental issues of an area. Trees contribute of course in the production of oxygen (trees are most effective when they are a little older), are cooling the air in the summer and reduce wind and storms and make people more relaxed. Next to this, trees are housing birds, bats and other animals and smaller plants. And they have a function in reducing noise and fine dust, humans bad ‘habits’. Although the ecological and value cannot be named in euro’s, images of the thick smog of Beijing show how things can go wrong with fine dust. Next to this, world leaders- we- have decided this weekend, that our planet should not heat up more than ‘really less than 2 degrees’ in the future. We need all the help –however small- to make it to our climate goal targets and every tree is helping.

Identity and Cultural History

Trees are contributing to the regional landscape identity and cultural history of the place and this should be an argument in the discussion as well. Because trees, individually planted or in rows, which we call avenues or alleys, are part of the history of our cultural landscapes. They play an essential role in the character and identity and branding of a specific area. Many people are thinking now, so what? But landscapes with incensed avenues and forests, like on the boarders of the Veluwe, are being appreciated higher than open, flat landscapes with few trees by tourists, visitors and owners. And happy tourists and visitors are drinking more coffee and tea, staying overnight and shop and therefore, contribute to local economy. And this is leading to more functions for residents and higher house prices, which was shown in the clear graphics and numbers in the ‘Gemeenteatlas 2015’.

And the beauty is not only in the presence, but also in its size, which cannot be restored easily and quickly. When a part of the city is restored, like Utrecht is doing, the process will take 10-15 years. If an old tree needs to be replaced with another rather big one, it takes much more effort to do so. In the Netherlands there is a saying; Tree big, planter dead! (Boom groot, plantertje dood!).

Lost Beauty

Meanwhile, many trees and avenues have lost so much quality already. Recent research at the chair of Landscape Architecture at Delft University of Technology shows figures on the avenues in the Renkum community, a municipality on the boarders of the Veluwe. Over the past 140 years the presence of avenues diminished heavily. While Renkum had 140 different avenues or alleys in 1870, only 40% of these avenues were still intact in 2013. The quality of these avenues has diminished even further. While in 1870 65% of the avenues were still intact, in 2013 only 20% of the avenues were still in good condition. These are just a few numbers of what has happened, but you can already imagine how the appearance and quality of this area has been altered by the loss of the previously present avenues.

Future Driving

The timing is so to say a little wry in this period of time, when specialists are testing systems for cars to drive safely on roads in a ‘super-cruise control mode’ on long distances, which we saw on the news a couple of month ago.So, trees cannot drive cars, but people can. Let’s find specific solutions in which cars can drive safely and trees can stand next to the side of the road.

Hereby, I want to thank Lotte Dijkstra, Karen Cubells, Michiel Pouderoijen en Frits van Loon for their contribution to the blog.

More readings and links:

- Blog of Piet Vollaard ‘Kappen met kappen’ on Archined (11-11-2015): https://www.archined.nl/2015/11/kappen-met-kappen/

- Knights of Trees, site of Rotterdam: www.bomenridders.nl and site to the IJsselsteijnse Knight of Trees: http://www.bomenridders-ijsselstein.nl/dreigende-bomenkap-langs-provinciale-wegen/

- Manual of CROW: http://www.crow.nl/vakgebieden/verkeer-en-vervoer/wegontwerp/vraag-en-antwoord?page=1&searchsort=sco

- Research on the Changing Quality of Lanes in Renkum by C.M. Dijkstra, K. Cubells Guillen, G. Verschuure-Stuip will be published soon.

Dikes in perspective

The dike as a landscape element takes on many shapes [1]. Depending on their form and location, dikes determine the ‘face’ of the Dutch polder landscape. Of course vegetation, land allotment and building development patterns also play an important role. Yet dikes are vital to the landscape’s appearance: apart from their form and location, their uninterruptedness defines spaces in a landscape and connects areas with each other. Dikes make differences in the polder landscape legible: a dike in a river landscape is different from one built in a sea-clay or peat landscape or the area around the IJsselmeer lake. Dikes therefore contribute to the identity and variety of the landscape. They simultaneously provide coherence, a sense of space and a rich variety of appearances. But how do you get a grip on the dikes’ spatial significance?

The seminal publication Het toekomstig landschap der Zuiderzeepolders (literally, ‘The future landscape of the Zuiderzee polders’ [1928]) provides some leads. In this manifesto of Dutch landscape architecture, planning experts such as D. Hudig and T. van Lohuizen described the importance of dikes as follows: ‘The dike is a significant element in every polder. Located on the border, it provides a view on one side of the landscape at its foot, unfolding its particular structure; on the other side it provides a view of the surrounding land, which often has a completely different character. The long, broad slope is one of the dike’s most beautiful features (. . .)’. From this, it can be inferred that a dike’s spatial significance depends on your vantage point, on the perspective you choose for reading and understanding dikes in the landscape. There are at least two different ways of looking at dikes: from the air and from the ground. In these vertical and horizontal perspectives features such as the dike’s course, cross-section and revetment always play a different role.

The course, cross-section and revetment of the dike exert great influence on its spatial significance. Plan for a new sea dike in the IJsselmeer area (Netherlands), Jacob van Hoorn, 1737 (source: TU Delft Library, Kaartencollectie Trésor TRL33.5.07)

The view from the air

You get a bird’s eye view of the dike system regardless of whether you view it from the air or on a map. It becomes clear that dikes form spatial patterns that endow the landscape with structure. They provide cohesion in the landscape and are also the interface between land and water, or between different polders that are enclosed as spatial units. Dikes ‘frame’ different types of landscape and landscape units. Like the black lines that separate the pictures in a comic book, the dikes are the green lines that demarcate the Dutch landscape. This also means that dikes are connecting structures:  through cities and nature, they meander everywhere and connect the coast with the hinterland. This is significant, not only for plants and animals but also for humans.

Dike patterns also make the history of reclamation in the polder readable: in Friesland (NL), for example, you can see an intricate, irregular pattern of dikes and quays, an echo of the early individual reclamation that from the time of the Romans gradually developed into ring dikes; you can discern the haphazard process of diking accreted silted soil in Zeeland, and the systematic reclamation of the West-Frisian and Holland-Utrecht peat areas that started in the early Middle Ages. The ring dikes mark the areas of reclaimed land that have lain low in the landscape since the sixteenth century. Dike patterns are a record of the formative force of water and the way humans have dealt with it. Natural processes of sedimentation, erosion and stagnation through water provide the foundation for a rich variety of polder landscapes in the coastal, river and peat areas. Dikes also reflect technological progress, such as the Dutch Delta works, the Afsluitdijk (the enclosing dam of the IJsselmeer) and land reclamation in the IJsselmeer area. In a nutshell, the shape of a dike makes it possible to read how we have dealt with water: from the small-scale and winding in early times to the very large-scale and rectilinear today.

The development of the landscape expressed by the pattern of dikes, here visible on the island of Goeree Overflakkee (SW-Netherlands) (drawing by: Michiel Pouderoijen, TU Delft)

The view from the ground

Viewing the dike from the ground means you stand on or next to the dike or see it from a distance. Here, conditions affecting visual perception such as vantage point, the viewer’s elevation and viewing direction, movement, and the weather play an important role. The interplay between the dike’s sideways slope, structure and revetment determine its spatial significance at eye level.

In the field, dikes are spatial borders: they determine the form of the landscape, the two- and three-dimensional composition of vertical elements that define the landscape space. The composition determines the scale, proportion, orientation and significance of the space. Every dike has its own specific characteristics, with form creating the connection between a landscape’s history and our spatial experience. Apart from the sideways slope, the cross-section and revetment are also important. The dike cross-section describes the dike’s height, the angle of inclination of its slope, and the width of the crest and the toe. This is important because a high, steep dike creates a different spatial effect from, say, a gently sloping wide dike. Whereas a steep dike makes a spatial border palpable, a dike with a gentle slope tones it down. Whether a dike is revetted with stones or only with grass also plays a role. The revetment is an indication of the function and use of the dike’s inside and outside, and it can create visual continuity or, in fact, contrast. Trees reinforce the three-dimensional effect of the dike but due to technical considerations they cannot always be planted.

The dike as landscape balcony at Wörlitz, Dessau (Germany) (photo: S. Nijhuis, 2013)

Standing on a dike is like standing on a landscape balcony with sweeping views on either side – stretches of water or polder, or both. Movement plays an important role in how we experience these landscapes because there are often roads or cycle-paths on top of the dikes. Seen from the car or bicycle, aspects of the landscape succeed one another like a cinematic experience, as we float above the landscape. The straight or curved course of the dike then provides variation or calm and opens up perspectives on the landscape. Here, too, the cross-section strongly affects spatial experience: if the road and cycle-path are both located on the crest, for example, their width might diminish the special experience of the dike, whereas if the cycle-path is located on the dike’s flank more of the dike remains.

The dike’s continuity makes the landscape’s cohesion visible and connects the local with the supra-regional: in the Rhine-Meuse river area dikes follow the course of the rivers with  occasional sharp bends around deep lakes that bear silent witness to past dike breaches; in the peat area dikes support a system of drainage lakes and cut through the low-lying polder land; in the coastal area dikes are like the layers of an onion, enfolding and merging the land as it grew; and the dikes in the young IJsselmeer polders and the ring dikes around the polders of reclaimed lakes make it possible to experience the former stretches of water as landscape spaces.

Research through design exploring spatial qualities of re-enforced river dikes (source: Y. Feddes & F. Halenbeek, 1988, compilation: S.Nijhuis)

In conclusion

Taken together, these ways of looking create a basis for approaching the dike from a spatial perspective and endowing it with aesthetic landscape qualities. Thus, if work is carried out on a dike attention must be paid not only to safety and multi-functionality but also to scenic beauty. Carefully designing a dike’s course, cross-section and revetment ensures its contribution to the identity, spatial aspect and variation of a landscape. The design disciplines are vital here: landscape architects and urban planners play a key role in planning developments that affect the landscape, and they should take the lead in developing the expertise and tools to formulate the dike as an object of spatial design in a context of functionality and social embedding.

 

Note:

[1] This text is published as:  Nijhuis, S (2014). Dikes in focus. In EJ Pleijster & C van der Veeken (Eds.), Dutch dikes (pp. 72-75). Rotterdam: nai010 publishers. In Dutch: Nijhuis, S (2014). Oog voor de dijk. In EJ Pleijster & C van der Veeken (Eds.), Dijken van Nederland (pp. 72-75). Rotterdam: nai010 uitgevers. Both available at: http://www.nai010.com/dijkenvannederland