Mosslandscape

In the near future, hardening will become a big issue in cities. Hardened surfaces might be useful for things like cars and bikes, but will lead to problems in combination with climate change. The introduction of mosslandscapes in cities will be a chanting solution.

During my research in Agniesebuurt, a neighbourhood in the north of Rotterdam, I counted all the materials in the neighbourhood, what is the surface of this neighberhood currently made of? Do we really need so many materials to form a neighbourhood? My survey showed that there is a huge amount of hardening; there are 84,000 paving stones, 9 million bricks and 110,000 m2 roofs. This comes down that the district owns 92 % paved surface.

This hardening rate in combination with climate change creates a problem, especially in Rotterdam. If climate change continues there is a chance that Rotterdam will experience floods in 2030. In the future more sudden rainfalls are exected, with larger amounts of water. In case of harsh rainfallls the rain cannot be absorbed and will directly be passed to the drain, this will then sit and overcrowded neighborhoods and streets will flood. Because there is a large amount of rainfall must be discharged suddenly also affect the rivers where the rainfall in enters overflows….

Not only the rainfal will become more suddenly and violently, but there will also be warmer and longer dry periods. Because we need a lot of water in these dry periods, for example our peat dikes so that it does not sag against subsidence, population growth, all of which have potable water for the crops. This leads to longer dry periods where we have a to short on water.

A life-sized sponge is the solution to these problems. The sponge absorbs water which can be returned in drier periods. A natural material that has the properties of a sponge is moss. Moss can absorbe its own weight 20 times. At the same time it offers many other positive attributes; it can filter air and water, insulate, encourage biodiversity, is lightweight, is low on maintenance-costs and grows on everything.

I propose to use moss to create a landscape within a district. A natural landscape that can grow and spread itself. It not only ensures that the water is absorbed and the water can return later, but it also gives the district a lot of green and nature back.

The water is included in the landscape. In the future there are many heavy rainfall a percentage will be absorb with the moss and the other percentage witch can not be absorbed can stored in the tank under the moss landscape. There are 4 to 5 points where the leftover of the rainfall can be collected and restored in the tank. Sphagnum moss is capable of filtering water with fresh moss but there have also been developed systems in which they used dried sphagnum moss to filter pools. Filtering happened again in the tanks under the moss landscape. With a dry period, the clean water returned to the moss this leads to natural streams and a cooling environment, a vapor system the water can also be returned to the people and environment for cooling. And so the circle is closed.

The result of the landscape is that it can record 12,600 liters of water at a time, 850,500 liters per year, 50 % of this is absorbed by the moss and evaporated, and 50% can be saved and reused. And the landscape enriches the district with a green stimulating environment.

Sanneke Tangel, 2015 Sanneke Tangel studies Spatial Design with a minor in Sustainability at the Willem de Kooning Academy, Rotterdam.