_ARTIKEL_ door Janka Csernák
CALTROPe is an answer to the challenge of Sea Level Rise. With this project, we aimed to create a future-oriented and innovative architectural solution responding to this diverse problem. For a complex, real and multidisciplinary response, the concept was developed by designer members of S’39 and invited professionals from different relevant fields.
The concept’s focuses
The increasing problem of sea level rise represents one of the most flagrant consequences of the global climate change. As the Intergovernmental Panel on Climate Change (IPCC) reported in September 2013: “Due to global warming sea level will have increased by 100 centimeters by 2100. The submersion of some five million square kilometers of the lowest lands on Earth is predictable, which is twenty times the area of the United Kingdom, causing massive migration and serious economic damages”.
There are two main factors evoking sea level rise: the growing volume of warming water on account of global temperature increase, and the melting of inland ice. In coastal zones, rising sea level endangers densely populated, low altitude big river deltas. This is not only a problem of losing natural greenlands, but significant amount of habitat, and also traditions and cultural values.
We focused on river deltas as, due to the low difference in elevation above sea level, they are extremely vulnerable lands. Deltas are incessantly built and evolved by sand and gravel river sedimentation pushing always a bit forward the estuaries in the sea. Owing to this sedimentation process, deltas originally conquered substantial areas from the seas every year. However, by today, human activity significantly transformed the natural run and hydrodynamics of our planet’s huge rivers by dikes controlling their flow, and bigger, bigger dams and reservoirs disturbing water yield. These interventions hinder transport and resupply of alluvium as well as its accumulation and integration into deltas.
Since ca. 500 million people live in deltas (this equals to the population of the European Union and to 8% of all inhabitants on Earth), for whom these zones mean home, life and living, sea level rise alone leads to disastrous consequences, but the situation will be exacerbated by the eventual destruction of more and more intense storms and sweeping hurricanes also ascribable to global warming. Thus vast areas of living spaces and agricultural lands may disappear or at least be endangered shortly. The densely populated tropical and subtropical countries with a weak economy are most vulnerable to these threats. The prospective soar of uninhabitable zones foreshadows a modern age mass migration. Hence we focus on the deltas of these regions in the followings.
The importance of mangrove forests
Mangrove forests grow in tropical and subtropical foreshore habitats. Mangrove swamps are composed of 40-60 species in about 20 genera and in a bit more than 10 families. Endemic plant species adapted to the waving and the tidal fluctuations of the littoral swamp by evolving a special profuse strong lateral root system for better foothold. The immense root system obtains oxygen from the air via negative geotropic (growing upward) pneumatophores, i.e., breathing roots.
By developing abundant root network while growing, trapping alluvium from the river and the waves, these trees create the grounds of their own habitat as they contribute to soil formation and prevent neap tide backwash from eroding the coast. Thanks to these properties, mangal is the only natural plant association on Earth that helps to gain land from the sea. Besides the protection against constant effects, mangrove provides shelter against extreme weather events. It absorbs 75 percent of wave energy, so the mangal-entrenched land is relatively protected against storms and tornadoes.
Despite its importance, mangal has become one of the most endangered tropical ecosystems on Earth by the millennium. In addition to direct human intervention (deforestation), indirectly prevailing processes are also reducing the coverage. Because of sea level rise and the reduced amount of influent alluvium, the mangrove zone situated between the tidal and mean sea levels is moving up, following the new coastline.
How CALTROPe lace works in concept
After the examination of the dynamics, the flow characteristics, and the ecological regularities of deltas, it was concluded that the intentional and increased retention of water-borne alluvium, carried in big quantities by delta rivers, can be the key for the protection against the effects of water level rise. Therefore our aim was to elaborate a straining system that is able to catch alluvium and integrate mangroves into an architectural structure in an organic and controlled way. It was essential to design such modules that initiate positive changes in a symbiotic way with local endowments on the critical coastlines.
The CALTROPe module system is easy to create and install with given local resources. The lace is to be built in 1 or 2-3 levels. The height of the system is defined by the mean water depth on the shore. Mangrove saplings are to be planted in the flared hollow arms of the top level. In time, the trees’ roots will enmesh other units as well, creating a lively sifter layer on the constructed one. The prefabricated modular system serves essentially as a supportive frame and helps the trees root and grow strong where the water would otherwise be too high. On the foreshore, the special mangal-needs (water depth, salinity, etc.) are artificially established under water on the CALTROPe lace. The structure ensures appropriate life conditions for the plant, even in several-meter-deep water. That way, the intricate root system and the human-built construction form together a natural dam that retains alluvium and adds it to the shoreline soil.
The system consists of numerous examples of one single element type. The units can be combined both horizontally and vertically. Modularity allows adjustment not only to the conditions at the time when the lace is installed but also to evolving circumstances. This feature is crucial respecting the protean dynamism of delta geography, especially if one takes into account how little we know about climatic changes and their potential impact on sea level. The units serve at the same time as a framework, as incubators for the planted saplings, and as a flow-decelerating wall contributing to wave protection and sedimentation. The modules’ blend is a special mixture of concrete developed for this purpose, always containing local materials. In 15-20 years, as the plants get stronger, the concrete lace starts to crumble and decomposes. Eventually, the crumbs also become part of the alluvium and integrate into the sediment.
The installation of the CALTROPe lace consists of a gradual development process of several steps. 4 to 5 years after planting, the saplings grow strong enough to be self-supporting, preserve soil and strain water. Sedimentary processes start immediately and keep on banking up alluvium incessantly. The lace always curves and forms closed lines to enhance alluvium capturing and structural stability.
Effects on the local population
These areas do not only function as a dam, a filter or a pier, CALTROPe’s “watery esplanades” also provide habitat for other organisms that create the possibility for local population to earn a viable and sustainable living. From the very beginning untill the end and after, every step is preferably taken in a participatory way. The production is made on the spot, and the whole process involves locals with community work. The presence of the lace and the care for the flora prove useful in several ways for the locals. The participatory factor brings people together and reorganizes the community. Collaboration improves the community’s sense for self-supporting, constructive management strategies that utilize local resources. There are numerous examples already for such integrative projects that revitalize communities especially in harsh circumstances. Locals can use traditional strategies of foresting and fishing, and huge improvement can be observed in short time in the way they relate to their very environment. The knowledge they already have becomes valuable and essential, and being involved makes people aware, responsible and conscious about their lands.
Sea level rise has become an inevitable and unpreventable fact. Yet we believe we do not need to resist it, but rather try to work with the expected dynamics. Using the existing resources to catalyze nature’s processes is a possible, respective and ecological answer to the challange.
S’39 Hybrid Design Manufacture is an artist collective which primarily deals with complex artistic design. The subject matter of design typically relates to some form of spatial situations, such as installations, artistic design of buildings, actions and artworks in public spaces. The permanent members of the group are often joined by freelance artists, experts or university students in various projects. The studio hosts a variety of innovative events and workshops. Due to its several-year operation, its downtown location and its regularly organized events, the place is a great meeting point for creative from very different fields.
The team behind CALTROPe:
Gergő Balázs – Biologist, diver
Anna Baróthy – Designer, project leader
Janka Csernák – Designer
Dániel Csomor – Architect
Viktor Grónás PhD – Associate Professor at Szent Istvan University, Agricultural Environmental Management Engineer, diver
Péter Kovacsics – Graphic and motion designer
Viktor Pucsek – Designer, 3D designer
Péter Vető – Designer, 3D designer
Melinda Bozsó – Designer
Kata Kerekes – Graphic designer
Vera Krauth – Architect student
Ábel Kurta – Industrial designer student
Nóra Lajkó – Painter student
Veronika Szabó – Industrial designer student
Prof. János Józsa – Head of the Hydraulic and Water Resources Engineering Department of BME University