Linear limbic spaces between land and sea: Landscape designing in river Evros’ delta. Eleni OUREILIDOU Faculty of Engineering, School of Architecture, Aristotle University of Thessaloniki, Thessaloniki, Greece email@example.com
Abstract Delta of river Evros, located in the frontier between Greece and Turkey at the crossroad of east and west culture, consists of a physical form in the borderline between land and sea. Landscape designing in a river’s delta environment requires the analysis of physical, geological, geographical and building reserve parameters. Taking these factors into consideration, a strong conceptual background is formed, which examines the significance of the borderline as a matter of structure both in the existing environment and in the proposing one. In order to create a limbic space from the scratch and to implement it in the landscape of Evro’s delta, my research focuses on the formation of a linear structure. As a result, every particular physical procedure, which can generate a linear form, is thoroughly examined. The requested linear structure is found in the pre-existing microstructures of metals, which is transferred in the 3d space under the certain conditions of lineation and cleavage. As far as the design process has been developing, the final curves create a route with several forks interacting with the characteristics of the given environment and resulting in the creation of dry ecosystems inside the flooding areas of the river’s delta. In the end the possibility of creating new ecosystems with different characteristics inside existing ones through the creation of limbic spaces is of great importance and could create a future approach in landscape design. Keywords: landscape designing, landscape analysis, microstructures, borderline, limbic space
Delta of river Evros, as a physical phenomenon, triggers of human curiosity since ancient times. According to Plutarch, delta was known as “Rhombus”, an expression to describe the constant penetration of the water in the land and the formation of the river’s branches. Nowadays, Evros is considered to be the longest river flowing in the Balkans. It stems from Bulgaria and just before empting into the Aegean Sea, it bifurcates forming a biotope of great value, defined by two territories. During the winter time period the land of the northern part of the delta stays dry, creating proper conditions for cultivation, while the land of the southern part is flooded, preserving the growth of rare plant communities and animal species. Geographically, river Evros’ delta is a tabular ground occupying the intermediate space that separates Greece from Turkey, Europe from Asia and the West from the East. As the river flows, it creates the natural linear border between the two countries. Although both of them are claiming its ownership, the only temporary residents of the site are the illegal immigrants and the birds. Furthermore, during the past years, the construction of dams, dikes and artificial canals undermined its existence, resulting in the gradual degradation of its ecosystem. Being a vast territory, almost completely abandoned, river Evros’ delta provokes feelings of insecurity and disorientation. The reasons are the innumerable natural and artificial water canals and the fact that the environment of the delta is constantly changing, since the traces of previous conditions are vanished due to the eternal water movement. Another fact is that the birds overpower the presence of the humans, enhancing the natural sublime but also undermining the possible aesthetic dynamics of the landscape.
People have to look to nature and if they learn to look, it will become landscape . Thus, the initial purpose of the intervention is to recall the human presence on the site and to enrich their overall experience of this rare natural formation. The necessary frames should be proposed in order to manage the spatial quantities of the territory and subsequently to transform it into landscape. Possible way of framing is the construction of paths and arrivals that guide the visitors’ movement, highlighting interesting places and providing a way to look at the nature. At first, the structural characteristics of the landscape are defined according to the physical and geological parameters of the landscape. From the structural point of view, river Evros’ delta landscape consists of a patchwork of surfaces along with the fishermen’s huts spread locally and unorganized over the entire area. Thus, surfaces and points undermine the existence of the linear form. The already existing network of the dikes is inadequate and therefore, it requires the implementation of a new route, which can interact with some of them, by reshaping them, or diverting them. This new route extends mainly along the flooding area of the river Evros’ delta, intersecting vertically with its branches. Its position derives from the topography of the site and especially from the visible and invisible borders of the landscape. The visible borders concern the areas of the alternative plant communities, and the invisible borders underline the areas of different water salinity, including also particular areas of birds’ activities as they are denoted in Fig.1. After detecting where the new route extends, the strong conceptual background generates also the possible designing methods. The design process focuses on the creation of a linear form that derives from the borders of the landscape and occupies the limbic space between heterogeneous surfaces such as the ground and the water. The intervention conceptually intends to create a megaform. In the past, megaforms were distinguished thanks to their capacity to act as a catalytic agent in the context. They were able to create new states of equilibrium, but still were perceived as consistent objects, providing a sense of continuity . The proposed linear form interacts constantly with the context of river Evros’ delta and positively transforms it at a larger scale, acquiring a conceptual correlation with the former megaforms. Since the design process triggers of linear forms, the requested procedures that are able to generate them, are found in the geological forms of the landscape and especially in the transitional spaces of the local microstructures. The geologic turn reveals the vitality of the earth itself and proves that matter is not passive; it awakens the ability to discern the force of things . The examination of the typical geological microstructures proves that the emerging linear structures bifurcate and reunite. The initial designing purpose is to revise the geometry of these lines according to the established compositional rules and then to apply them in the context by preserving their proportions and their flowing characteristics . Nowadays, there is an increasing interest on the way we are living on the planet earth, and the way we interact with the geological phenomena. It can be claimed that we are like walking rocks, as part of our aliveness is composed of geologic materials such as calcium, iron and phosphorous . The ground is no longer perceived as a thin, folded surface to build upon but something deeper and meaningful. Additionally, the geological form devises new regimes of perception of the nonhuman . Therefore, by analysing the existing landscape to its geological attributes and by transforming the results of the analysis to the design procedure, it is possible to enable the visitors of the river Evros’ delta landscape to see and sense the slow and vast geologic dynamics as visible flows, delivering at the same time the knowledge of the emergence of the geological space. In the end, the purpose of designing the limbic space between the land and the sea is the perception of the natural landscape along with the experience of the geological landscape. 1.1 Exploring the physical and geological context Landscape designing in such a fragile ecosystem, requires the comprehension of both visible characteristics and invisible procedures, which contribute to its topographic formation. All the physical and geological parameters are taken into consideration so that the specific territorial relationships of the site can be explored and defined as the conceptual background of the project. As a functional apparatus, a river’s delta enables the gradual expansion of land over sea, through the creation of alluvial depositions. Earth material is extracted from high speed river’s flow areas and is later on reposed in the estuary of the river. This procedure of subtraction and reposition indicates the gradual preponderance of land over sea. Before the river debouches into the sea, it widens and creates a branching system, which extends like the Greek letter Delta (Δ). Structurally, there are four main delta types: the radial type of delta, the birds’ treads type of delta, the lobed type and the sagittal type as they appear in Fig.2. Evros’delta belongs to the lobed type, because the sediments caused by the flowing water of its branches create irregular protrusions around lobes .
Fig. 1: The borders of the plant and birds communities.
The network of the river’s branches and the water canals monitors the mixing process of the sweet water of the river with the salty water of the sea. Along with the movement of the underground water, salty sea water penetrates the land and causes a constant change of the substantial equilibrium, which is crucial for the vitality of the ecosystem. On the one hand, the discharging areas of the underground water form layers of organic material, which is essential for the growth of the rare vegetation, and on the other hand, superficial waters classified according to their salinity, creates salty and sweet water lakes. The most important lakes of delta’s ecosystem are: Lake Drana, Lake Nymfon and Lake Paloukia, and sustain the accumulation of genetic material and nutritional substances. This constant change of the salinity of the water is also responsible for the growth of the plant communities. The most important components of the ecosystem’s plant diversity are: the halophytic vegetation, which grows because of the high water’s salinity, the aquatic vegetation, the riparian forests and the cultivated fields. Apart from the movement of the water, another crucial physical parameter that configures the landscape is the depositional power of the wind, which results in the creation of sand dunes and contributes as well to the growth of different types of vegetation . All these plant communities appear in zones and in combination with the water lakes define the landscape as an extensive horizontal field of interconnected surfaces. The internal sustainable relationship between the growth of plant communities and the movement of the water establishes a perfectly regulated mechanism that supports the ecosystem, and determines the existence of avifauna. Rare species of birds can find a shelter during their long migratory trip, establishing their own boundaries in the landscape. There are areas where they rest, move and reproduce, determined by the consistency of the ground and the vital ingredients of the vegetation. Additionally, as far as the geological background is concerned, linear formations, tectonic fabrics and transitional forms are the visual results of the hidden geological procedures that take place both in micro and macro scale. The starting point of this research derives from the alluvial depositions of the river Evros, which under certain conditions of pressure and temperature can create sedimentary rocks, appearing in the landscape at most of spatial and temporal scales. By definition, deposition proceeds when sediments, soil and rocks are added to a landform by building up layers. In some occasions, flows imprinted on the microstructure’s surface of the sediments, create interesting linear shapes and reveal natural procedures and physical forces that formed the sedimentary rock through the ages. Thus, the microstructures of the landscape can be perceived as an icon of the infinite geological processes. In macro-scale, two layers of different sediments and rocks can never be in abutting engagement with one another. There is always an additional layer, which exists between them and is always positioned in vertical direction, known as the phyllitic layer . These vertical layers along with the cracks that are identified on the rock mass are the most obvious linear forms of the underground geologic formations. .
Fig. 2: The structural types of delta. From left to right: the radial type, the birds treads type, the lobed type and the sagittal type.
In micro-scale, there is a variety of structures produced by procedures, believed to be chaotic. Two of these procedures are responsible for the unexplored spatial geometries: foliation or cleavage and lineation. The foliation causes the division of the microstructure’s surface into layers, while the lineation defines the elements of the microstructure that display a standard linear orientation. Both contribute to the emergence of the tectonic fabric . Furthermore, geological parameters form the folds of the ground, which structure the matrix of the river’s water flow. River’s route is defined by three main stages: the stage of youth, the stage of maturity and the stage of anility. These stages are classified according to the section of the riverbed. During the age of youth, riverbed section is shaped like “V”, which means that the ground is pretty sharp resulting in the creation of waterfalls. Subsequently, the riverbed is shaped like “U”, and the river follows a curved route, which locally forms meanders. Although during the first stage, the river erodes, during the next stage the river deposits. In the end, when the river starts to bifurcate, the banks become plain, leaning towards the sea. The water volume is very low implying that the deposition of the extracted material reaches the highest point as the final stage of anility . 1.2 Introducing the concept of the “borderline” The borderline identifies the context as the limbic space between controversial physical phenomena. Delta’s environment appears to be the hinge between the physical transactions, supporting the bipolar territorial relationships. While Evros provides the ground with sweet water, forming the surfaces of the corresponding vegetation and the water lakes, its delta accommodates the slow penetration of the sea streams inside the territory. The water surfaces become mixed and configure areas of different water salinity and areas of controversial plant communities. The tide constantly changes the pre-established orders and enables the coevolution of the dipoles: land and sea, areas of sweet and salty water and the relative plant communities. According to the geological phenomena, the borderline concerns the phyllitic layer, which is positioned between the rock masses made of different materials: the lava or the sedimentation. The phyllitic layer exists also between the layers of the masses created in different time periods. In the micro scale, the concept of the borderline appears also in the tectonic fabric, which consists of two main structures: the cleavage domains and the cleavage lamellae or the microlithons. The relation between the cleavage domains can be parallel, anastomosing or conjugate as it is denoted in Fig.3. Since the microlithon is located inside the cleavage domains, the borderline appears as the transitional space that separates the one from the other and it can be either gradational or discrete , as it is shown in Fig.4. The tectonic flow takes part along the transitional space between the cleavage domains and the microlithons, or else in the limbic space between them.
Fig. 3: The relation between the cleavage domains. From left to right: the parallel, the anastomosing and the conjugate.
Fig. 4: The transition between the cleavage domains and the microlithons. From left to right: the gradational and the discreet.
Transforming the design process from the physical and geological principals
Primary design purpose is to explore the possible physical and geological parameters, so that they can be transformed as the main conceptual tools for the design process. Actually, during the design process, there are two distinct stages: the stage of research based mainly on observation and the stage of proposal based mainly on composition. The concept of the borderline is introduced in order to define the structures that emerge from the osmotic procedures of the physical and geological phenomena. In order to compose a linear structure, the design process focusses on the main procedures that are able to generate it. The first procedure derives from the physical background of the river and the way the folds of the riverbed are formed. The second focuses on the geological background and especially on the characteristics of the rocks’ microstructures. There is a wide range of patterns to be explored, which display lines and surfaces and are able to provide the design process with the essential structural instructions. The examination of a variety of such microstructures including the local rocks leads to the detection of a particular rock called “rhyolite”. The root of the word comes from the Greek verb “reo”, which means flow. Through the observation of the rhyolite’s microstructure, it is noticed, that the tectonic fabric is an imprint of the flows that were created when the original material formed the rock. At first sight, the flows of the rhyolite seem to be irregular. After observing the sequence of its patterns formed through the ages, under specific environmental conditions, it is observed that the initial linear forms gradually acquire additional curvature points and start to bifurcate and relink. As they extend on the microstructure’s surface, the linear forms occupy lenticular transforming spaces framing the cleavage domains as it is shown in Fig. 5. The microlithons appear inside these lenticular shapes. The linear structures extending along the transitional field between the microlithons and the cleavage domains are chosen to be used in the design process. Thus, in order to reproduce them, the design process triggers of the geological procedures that are able to generate them: the foliation and the cleavage. 2.1 Designing the limbic space The design process establishes possible ways for the application of the foliation and lineation on the plain board surface, in order to form the limbic space between the surfaces of the cleavage domains and the microlithons. At first, the surface is divided into tandem stripes according to the division of the rock’s microstructure into layers, imitating the way foliation is performed on the rock. The stripes are not completely detached from the surface, because otherwise it would result in the creation of singular useless stripes. Then, a curved linear system is imprinted on the cleaved surface, in an attempt to operate the procedure of lineation on it. Different creased surfaces are produced with imprints of alternative linear systems on them. After the particular linear system is established on the surface, the model is put under pressure and as a result it creates folds, which could resemble to the shape of the riverbed’s ground. Afterwards, the wrinkled surface is additionally modified embedding some physical orders. As it is already mentioned, certain folds of the riverbed direct the water flow and determine its stages. Numerous folds that mark the beginning of the route on the surface create a rough background, just like the stage of youth. Subsequently the folds of the surface become gentler and the linear system forms meanders. The end of the route is marked by a completely osmotic field resembling to the final stage of the river, when the folds of the surface become almost plain. Based on these physical principals, the initial random folds are adjusted according to this physical conceptual background.
Fig. 5: Typical microstructures. From left to right: the gradational transition between cleavage domains and microlithons, the discreet transition and the lenticular shape appearing inside the cleavage domains.
Apart from the regulation of the pleated surface, some additional orders are applied to determine the geometry of the linear structure that is inscribed on it. The analysis of the applied curving system includes the definition of the distance between the curvature points, the regarding angles and the proportions. The process that leads to the regulation of the curves is described here. At first, a single line is selected to be slightly deformed through a constant change of its curvature angle, just like the sequence of the rhyoliteâ€™s microstructure. The results of these deformations are drawn one after the other and create a regulated two-dimensional linear system. A single line is again pointed out of it and is placed in mirror position in order to create the lenticular shape according to the cleavage domains appearing in the microstructure. This along with the slightly deformed lines consists of the core of the infinite system of the curves (Fig. 6). The additional rules concerning the distances and the angles stem from that core and are repeated along the rest of the system and regulate it. Thereafter, the spatial articulations of the deformed multiple curves along with the lenticular shapes are inscribed on the divided surface and create a model of artificial contour lines (Fig. 7). In the end the divided surface with the vertical contours, is put under pressure. The stripes move because of the pressure and the linear imprints create folds on the surface. The angles and the proportions of the distances that define the points of curvature are repeated except for the existence of a particular angle that provokes a point of instability in the linear structure. All the lines have a standard orientation and along with the folds generate the route, which forms an osmotic field like a regulated artificial riverbed (Fig. 8).
Forming the requested syntactical background of a curved line synthesis
In order to explore the syntactical background of the curved line synthesis, the distances, the angles and the proportions of the conceptual linear structure should be applied on a route that derives from the context. The linear structure is reshaped as it adopts the contextual characteristics. The application causes the relocation of its curvature points, while its angles and its proportions stay the same.
Fig. 6: The core of the infinite linear system. From left to right: the form of the lenticular shape, the distorted curves of the system and the final outcome of the codification.
Fig. 7: The linear system according to the rules of the core and the alternative regulated linear systems.
Fig. 8: The model of the pleated surface. From left to right: the folds that define the beginning of the route, the bifurcating and relinking curves and the multiple folds that define the end of the route
As it passes through the interesting areas, the deriving route is deflected locally and in particular occasions enters in to the water. In this point it starts to extend in a different way, acquiring multiple curves according to the geometry of the artificial contour lines that were established before. The single line is replaced by the pattern of the curves, which form the transitional osmotic field between the route and the water surface. Its spatial formation associates two contradictory elements and derives as an expansion of the coastline that marks lenticular grounds within the larger water surfaces. Initially, the structure of the limbic space consists of two agglomerated parts: the torn surface and the folds generated by the lines, resembling to the rock mass. Both of them enable the variable curvature of the surface. On one hand, the divided surface illustrates the procedure of foliation where the parallel stripes represent the traces of the divided layers of the rocks’ micro-surface. On the other hand the linear imprints that generate the folds indicate the procedure of lineation and provide with the horizontal continuity. In order to be incorporated in Evros’ delta landscape, these elements interact with the spatial characteristics of the context. The surface where the geological procedures were performed is replaced by the water surface of the context. Furthermore, the discontinuities caused by the movable, almost detached, stripes are now inscribed in the landscape through the intermediate voids that have been created as it is denoted in the second model of Fig. 9. These parallel vertical surfaces consist in the backbone of the new and flexible structure and are reformed in order to support structurally the bifurcating dikes. As a result, they display the undoing procedure of the interaction between the conceptual pleated surface and the existing surface of the context. The structural backbone provides a system of parallel buttresses endowing it with a sense of repetition and rhythm. In addition, some of them are subtracted, while others are added in another place along the linear intervention, in order to create spatial dilutions and densifications. These buttresses scan the entire curved line composition and like blades slice the bifurcating paths into several parts just as foliation subdivides the surface of the sediment’s microstructure. The backbone is made of steel and arises in Evros’ delta landscape as a piece of land art.
The composition is enriched by additional linear elements made of steel according to the procedure of lineation as it is shown in the first model of Fig. 9. These elements extend along the site like choreography, following the direction of the established dikes. They appear and disappear due to the linear pattern of the initial structure and they unveil traces of its preexistence. Most of these linear components are canopies, railings, ramps and bridges that are necessary for the compositionâ€™s interaction with the water. Ramps made of steel intervene between the branches of the paths and the water. In Lake Drana where the curved line composition starts to expand, tide and ebb occur every six hours. As a result, the parts of the construction that are made of steel are gradually corroded, imprinting the movement of the water on their surface. The limbic space reveals structural continuities and discontinuities and appears in this landscape as the transitional space between the land and the sea. Its materiality refers to the route that is formed as a dike made of soil and the rest of the structural elements that are made of steel. The use of casting and malleable materials tends to feed the confusion between artificial and natural. In the end, the artificial landform interacts with the existing one through its materiality. From functional point of view, the entire route extends to a distance of 25km, connecting the Lake Drana, which is mainly constituted of salty water, with the Lake Nymphon, which is on the contrary constituted of sweet water. When the route passes through the Lake Drana, it is formed according to the rules of the initial patterns. It is deflected and enters the water, acquiring the characteristics of the curved line synthesis. The metallic backbone appears in the landscape, fastening the system of the bifurcating dikes horizontally and disconnecting them vertically by separating them into several parallel parts. The flowing characteristics of the new dikes are enhanced by the extra metallic elements. The leading dike is designed for the cars and the bicycles and as it locally bifurcates, it enables the movement of the pedestrians. In a central point is also located a parking lot. The branches that are designed for the pedestrians are developed like extended steps following the vertical direction of the metallic backbone. There are four arrivals attached to them. Two of them are covered and are designed appropriately for bird observation. Therefore, they are placed on the highest level of the dikes. The rest are formed amphitheatrically, placed on the lowest level of the dikes and completely exposed to the water.
The use of the geological procedures in the design process results in the creation of a mutant landscape. The new hybrid landscape transforms locally the existing ecology of the landscape, exceeding the boundaries between natural and anthropogenic environment, between nature and culture. It refers no more to a simple plan of a garden; instead it creates a landform reconstructing the site itself. The geometrical discipline of the entire architectural composition avoids approaching the complexity and the smoothness of the natural form. The blades made of steel underline the remnants of the folded initial surface and provide the razed plane of deltaâ€™s landscape with a sense of sharpness. Thus, the existence of these parallel articulations that support the curved line system endows it with a sense of accuracy, revealing at the same time the possible ways of its morphogenesis. Additionally, the act of revealing the visible and the invisible borders of the context through the implementation of the transformed geological space deliver to humans a versatile experience of the entire landscape. The final outcome of the design process resembles to the act of scenography. The metal surfaces are gradually distorted because of the water chemical reaction with some of the metal substances.
Fig. 9: The syntactical elements of the curved line synthesis. From left to right: the spatial transformation of the lineation and the foliation.
As a result, natural forces, like the movement of the water, are exposed to human perception through the materiality of the construction. Furthermore, the lenticular dry precincts accommodate exotic vegetation and inform the visitors about the growing procedure of the vegetation. In the end, the project constructs a new topography through the constant interaction with the context of the Evrosâ€™ delta. The lenticular voids appear as holes in the water and create new forms of inhabitation, smaller landscapes that can be expansive according to the length and curvature of their artificial shore-lines. Eventually, exploring the matter of the borderline and composing the limbic spaces between land and sea in vast territories like deltaic environments establishes new boundaries for the existing surfaces and new ecologies.
Fig. 10: Top view of the linear structure that displays the way the route expands as it enters the lake Drana.
Fig. 11: Renders displaying the dry lenticular precincts and the relation between the natural and the artificial.
This paper is based on the diploma project with the title: A hole in the water, September 2012, supervisor: Vana Tentokali, professor , School of Architecture, Faculty of Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Published on Jul 7, 2013