Les deltas et les zones estuariennes sont les terrains les plus productifs et les plus fertiles du monde. En tant que zone de transition entre la mer salée et les rivières douces, les deltas et les estuaires sont caractérisés par une abondance de vie. Une grande partie de la population mondiale dépend de ces zones pour sa production alimentaire. Pour assurer une production alimentaire maximale dans ces régions, les rivières et les marais salés sont endigués et les dénivellations sont effacées, ce qui entraîne une impasse entre la nature d'un côté et la production de l'autre. Dans ce projet, on étudie la manière dont la production alimentaire peut être liée aux conditions naturelles et créer une riche palette alimentaire dans les limites naturelles de l'estuaire. Outre le delta néerlandais, de nombreux deltas africains sont toujours confrontés au dilemme suivant: vont-ils contrôler et exclure les conditions naturelles ou vont-ils suivre le rythme et la dynamique de la nature?
Avec la côte comestible des Wadden, on veut démontrer le potentiel d'un paysage alimentaire résilient et respectueux de la nature, où production alimentaire et nature abondante peuvent aller de pair. La côte des Wadden est un paysage unique. Les marées, les flux de sédiments, la saison et les gradients de douceur et de sel créent un paysage très dynamique à l'extérieur des digues, avec une grande attraction pour de nombreux oiseaux, poissons, crustacés et autres espèces de flore et de faune. À l'intérieur des digues, le contrôle optimal des sols fertiles d'argile marine assure une culture arable très rentable. De nombreuses tonnes de pommes de terre provenant de la première coquille d'argile sont expédiées dans le monde entier. Toutefois, cette situation ne pourra pas être maintenue indéfiniment.
En raison du changement climatique et de la montée du niveau de la mer, ce paysage d'abondance naturelle et culturelle est sous pression. La salinisation, les périodes de sécheresse et les précipitations extrêmes rendent la production d'une monoculture agricole de plus en plus difficile. En même temps, le paysage unique des marées, qui revêt une grande importance pour la migration de millions d'oiseaux et d'espèces de poissons migrateurs, est menacé d'être noyé progressivement par l'accélération de la montée du niveau de la mer.
Pour pouvoir aussi tirer parti de ce paysage abondant à l'avenir, un changement de mentalité est nécessaire: il faut passer d'une approche de contrôle, qui tente d'interdire toutes les incertitudes et tous les extrêmes, à une approche flexible, qui évolue avec la dynamique et la diversité du paysage. Cette approche constitue la base d'une nouvelle perspective: la côte comestible des Wadden.
Deltas and estuarine areas are the most productive and fertile grounds worldwide. As a transition zone between the salty sea and fresh rivers, deltas and estuaries are characterized by an abundance of life. Large parts of the world's population are dependent on these areas for food production. To ensure the highest food production in these regions rivers are dammed, salt marshes are embanked and gradients are wiped out, resulting in a deadlock between nature on the one side and production on the other. In this project Flux investigates how food production can be intertwined with the natural conditions to create a rich palette of food within the natural boundaries of the estuary. Other than the Dutch Delta, many African deltas and estuaries are still facing the dilemma; are they going to control and exclude the natural conditions or do they incorporate the rhythm and dynamics of nature? With ‘The Edible Wadden Coast’ Flux illustrates the potential of a resilient nature and inclusive foodscape, where food production and abundant nature can go hand in hand. The Wadden Coast is a unique landscape. The tides, sediment flows, the season and gradients of sweet and saline water create a highly dynamic landscape outside the dykes, attracting many birds, fish, shellfish and other flora and fauna. Within the dykes optimal control of the fertile marine clay soils ensure highly profitable arable farming. Many tons of potatoes from the fertile estuarine clay soils are shipped all over the world. However, this situation cannot be maintained indefinitely. Due to climate change and rising sea levels, this landscape of natural and cultural abundance is under pressure. Salinization, periods of drought and extreme precipitation make the production of a monoculture of agricultural crops increasingly difficult. At the same time, the unique tidal landscape, that is of great importance to the migration of millions of birds and migrant fish species, threatens to be gradually drowned by the acceleration of rising sea level. To be able to harvest from this abundant landscape in the future, a change in mindset is needed: from a controlling approach, one that tries to ban all the uncertainties and extremes, to a flexible approach: an approach that moves with the dynamics and diversity of the landscape. This approach forms the basis for a new perspective: The edible Wadden Coast.
In the edible Wadden Coast the landscape is the result of the dynamics and diversity of conditions. Building upon the variety of sweet and saline, wet and dry, high and low and clayey or sandy, a broad spectrum of conditions arises, providing both flora and fauna as a food-landscape. This richness of the area is making it attractive to live, work and recreate. In this way the Wadden Coast becomes a buffet that everybody, both birds and tourists, can eat.
The current system aims mainly at profit and bulk production of a few crops (in particular the seed potato). It therefore excludes uncertainties, while a system that thrives on the dynamics and diversity of the landscape can offer a possibility for a far larger spectrum of products: from potato to cockle, Salicornia to mustard and chard to smelt. Our menu in 2100 consists largely of local crops and catches, but also new forms of protein like seaweeds and insects. By looking at the Wadden Coast as a broad productive zone, where food production and nature are interconnected, an enormous broad menu arises. From the coastal area of North Groningen, sufficient varied food to maintain all the three northern provinces can be produced annually with this approach (Figure 1).
This productive landscape focuses mainly on the region instead of the world market and offers opportunities to close the cycles. By connecting farms, resources and food can be exchanged, making the area less dependent on fertilisers or concentrated feed. Simultaneously opportunities arise for local processing and promotion of sustainable and quality products from Groningen. Therefore, villages regain their connection with the coastal area and will profit off the new wealth (Figures 2a and 2b).
The Edible Wadden Coast offers an attractive future perspective for the long term and offers opportunities to resolve multiple current and prospective challenges within it. Six exemplary interventions on different locations along the Wadden Coast are forming a starting point to build strong spatial structures for the food landscape of the future (Figure 3).
Many open connections between the Wadden Sea and the hinterland have disappeared. By connecting the watercourses from the hinterland again with the tidal creeks, not only do the conditions for the migratory fish improve, it also creates new recreational hubs on the Wadden Dyke. These hubs form the starting point for excursions onto the tidal flats and are links in the food chain where fish, crustaceans, shellfish and other products of the salt marshes are brought onto the land and sold. The hubs are part of a wider network of routes and villages in the hinterland. By concentrating these activities here, waders can find peace on other places of the coast. The reintroduction of the scour sluice makes the passage for the migratory fish possible, the fish looking for a sheltered place to spawn. The scour sluice should also keep the fairways open on the flats outside the dyke and maintain the freshwater levels within the dyke by letting the heavier salt water in occasionally (Figure 4).
Local conditions will be exploited as much as possible in the agriculture of the future and cycles will be closed. More space will be given to the field margins, rows of trees and natural lands . Instead of draining rainwater immediately and discharging it onto the flats, local gradients can be exploited to retain the valuable freshwater. In particular the increase of organic matter on the slightly higher former salt marsh shores and the lower areas around the maren (the canals based on former salt water inlets), offer opportunities to retain the freshwater longer, to be released gradually into the agricultural lands. Closer collaboration between the arable farmer and the livestock farmer can ensure that fertilisers and cattle feed are being exchanged for the benefit of circularity of the agriculture in the area (Figure 5).
Salt marshes were part of the agricultural system, up to the 1990’s. The different stages of land reclamation development, trenches and drainage system ensure a micro-relief and a rich diversity in habitats. When this work on the salt marshes stopped, many salt marshes were clogged with sand and the rich diversity of habitats disappeared. A new look into the dynamics of the salt marshes offers both opportunities for food production, as well as contributing to the rehabilitation of the diversity on the salt marshes, offering opportunities for water safety. The clogged salt marshes will once in a while be ‘reset’ by excavating them. By dividing the salt marshes into a patchwork that is excavated at different times, various stages of development and heights of salt marshes occur at the same time. This creates a varied food landscape: Salicornia on the lower parts, young cattle on the mid-heights and grains and beans on the thin freshwater lens on the highest salt marsh (Figure 6).
Natural dynamics will be brought back in the Lauwersmeer, a freshwater lake in a former sea inlet. A flexible water level varies with the seasons and ensures a large diversity of conditions. The Lauwersmeer can serve as a freshwater reservoir during periods of drought. The biomass in the area is harvested in different phases of succession, like reed, wicker and wood. These materials can be used as building material elsewhere, for example for breakwaters in the saltwater marshes. An open connection with the tide of the Wadden Sea ensures a variable water level, variation in fresh and salt water and an ecological connection to the sea. With an open connection, fish can return to the Lauwersmeer so that Zoutkamp can be put on the map as a fishing village again (Figure 7).
In places where salinisation is predominant, it will be difficult to maintain the freshwater conditions. By accepting the salt in these places and by exploiting it through excavating the soil slightly and dyking it, the salty groundwater can be attracted, so that other places can be spared. Controlled experimentation in these areas, with brackish or saltwater conditions can provide a new basis for agriculture. These areas are offering opportunities for the development of new salt-tolerant crops, that not only bring a completely new flavour into the area but also provide knowledge for the cultivation of products in other delta areas of the world. The most saline areas can be exploited for livestock farms, spawning places for fish or resting areas for birds. The saline areas along the Wadden Coast can be exploited using collaborative management. The costs of the development will therefore not only be carried together, but innovations will also be shared with each participant and farmer (Figure 8).
Due to rising sea-levels, the future of the Wadden Sea has become increasingly uncertain. This UNESCO area is unique for its ecological importance for many birds and aquatic life. The faster the sea-level rises, the more sediment is necessary to let the tidal flats grow along with it. By reducing the area that gets flooded and runs dry with every tide, sea-level rise and sedimentation can keep each other in better balance by drawing in more sediment as compensation. New oyster reefs can offer a substrate that allows for increased sedimentation, causing tidal flats to be reinforced or new ones to emerge. The oyster reefs can play a part in the cultivation of seafood, like shellfish and seaweed, and through their position can contribute to keeping the fairways deep enough for navigation. The oyster reefs can, at the same time, be a tourist destination in the middle of the dynamic tidal flats. By concentrating these activities, waders and seals can find peace elsewhere on the flats (Figure 9).
These six interventions illustrate a possible first step within the Edible Wadden coastal realm, in which a dynamic coastal landscape creates a rich variation in conditions, products and usage. In this way the edible Wadden Coast provides an inspiration for the design of comparable African landscapes to illustrate, especially in estuarine landscapes, that a resilient food landscape can be established by working with nature.
All images by Flux Landscape Architecture