ROLE OF THE URBAN GREEN STRUCTURE IN CREATION OF PREFERRED URBAN ENVIRONMENT

© K.Zaleckis PhD, 2003

Text of paper to the COST C 11 "Green structures and urban planning"

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INTRODUCTION

One of the most important actualities and tasks for urban planning today is creation of sustainable environments. The search for sustainability of urban environment means a search for both higher and new qualities of townscape as well. Concerning the character of spatial planning these new qualities depend on the following things:

• New planning methods that enable the creation of more functional spatial models and structures;
• New functions assigned to planned spaces;
• New models and concepts for urban planning.

Creation of an urban green structure can help to add some new qualities to or to improve the old ones of an urban environment. Why? The term "structure" means location and order of related parts within one organism or system. Complex mind says that system is more then just a mechanical sum of its parts. Any system has a new quality that was not presented in its single part &endash; like a human body and its parts. According to the method of analogy of the abductional logic we can assert that if the urban green structure or system is created &endash; it should be able to perform some additional functions that are not performed by a single ore dispersed green areas.

It is well known from the practice and planning experience that the green structure (if it is understood as a sum of green areas that are territorially connected to each other and are acting together) can improve recreational, social and ecological qualities of an urban environment. Besides that it can help to create a preferred, more psychologically acceptable urban environment at a whole city scale. It is especially important for creation of sustainable city &endash; we have to satisfy as many human needs within an urban area as possible instead of looking for new areas outside a city. This paper summarizes both some theoretical premises and empirical remarks concerning the green structure and creation of preferred urban environment. The common aim of the paper is to show that the creation of preferred urban environment and the usage of the green structure for that purpose - are worth of consideration.

THEORETICAL PREMISES FOR CREATION OF PREFERED ENVIRONMENT

The objective of urban planning is to create a spatial and functional model of environment what meets the human needs and creates optimal conditions for the existence of both society and individuals. These human needs could be divided into the three main groups:

• The individual or personal needs (physiological, psychological, etc.)
• The needs of society (economical, cultural, communicational, social, etc.)
• The need to preserve an environment as a result of cultural orientation (values) and care about the future generations.

The division of needs into personal and social is a bit conditional. For example: when we directly satisfy the physiological or psychological individual needs &endash; indirectly social needs are satisfied as well because individuals make a society and society needs the healthy members. Here these terms mean just an obvious domination or the highest priority of the social or personal needs in a specific level of the spatial planning. In another words &endash; these terms shows what needs will be satisfied in the first place.

Both the second and the third group of needs prevail in the urban planning when the city is modeled. For example:

• When the all urban territory is divided into functional zones &endash; the "socially" significant functions are localized in this way;
• When these zones are filled up by proper natural or anthropogenic elements that are needed for functioning of the zone.
• When these elements are organized with the help of nature or urban frame.

It is important to stress that nature frame is not the same as urban green structure. Nature frame (together with urban frame) is a spatial planning method that is used for organization of the essential elements within territorial zone &endash; as a skeleton within a body. It uses the scheme of axes and nodes. The term "zone" is used to describe not the traditional functional zoning in town planning only. It means a method - division of any planned area on the base of stated important criteria. The green structure is a complex of green areas. As it was stated above these areas perform some additional functions together. The method of nature frame (together with other methods) could be used for planning of the green structure.

Traditionally the first group of needs (personal &endash; psychological, physiological, etc.) is more taken into consideration when local, personal, visually perceived and cameral spaces are designed and planned.

The following findings of environmental psychology are very important for the spatial urban planning and its priorities:

• There exists a human need to live in preferred environment &endash; "People tend to seek out places where they feel competent and confident, places where they can make sense of the environment while also being engaged with it". If this need is not satisfied it leads to the long time stress followed by decreased ability to work and loss of any motivation as a results of stress. "Along with the common environmental stressors … some define stress as the failure of preference, including in the definition such cognitive stressors as prolonged uncertainty, lack of predictability and stimulus overload". So, creation of preferred urban environment is worth to be considered in urban design and urban planning.
• The characteristics that make the environment "preferred" are determined by the different researchers and could be summarized as following: no visual stress production, legibility, coherence, complexity and mysteriousness. These definitions will be explained later in the terms of urban design.
• The important features of conceptual perception are determined. The whole big spatial structures and complexes are perceived conceptually only. We can perceive jus parts of a complex directly and visually. When we become conscious about something in conceptual way we create a mental map or model of that object. The higher mental functions as imagination and long time memory are used for creation of the mental model. All models are simplified and changed if comparing to reflected reality. This is true for the mental city model as well. The main features of the mental city model are following: 1. it is simplified, distorted and supplemented with additional elements; 2. whole city is created in imagination when a part of it is visually perceived (even if this part and a city are seen for the firs time); 3. the mental map replaces a material environment for our brain in many situations.

The first statement is true for all the models. In presented situation it means that imagination and long time memory could add some new things to the mental city model. This fact will be discussed a little later. The second statement means two things: a) Human psychological reactions to urban environment are influenced by a wide environmental context &endash; not by visually perceived objects only; b) We have some kind of pre-image in our imagination &endash; even before the real perception of the city starts. Example: if human will be dropped in the point within unknown city &endash; even in such situation he (she) will imagine a whole city. The third statement is very important if we speak about the emotional, psychological attitude to environment. It means that human reactions and responses could be based on the mental image but not the real environment (if we speak about reactions at the whole city level).

The main conclusions made on the base of these findings of the environmental psychology are following:

• We should take into consideration the psychological needs of human beings when the spatial model of a city is created. The whole city should be formed as the preferred environment &endash; not the local spaces only.
• We should create the preferred urban complex by creating and shaping the commonly imagined mental model of a city but not the material environment directly. This common mental image of city is described and researched by K.Lynch.
• The criteria of no visual stress production, legibility, coherence, complexity and mysteriousness should be used for evaluation and creation of preferred urban environment (this should be done through the common city image &endash; as it is understood in the works of K.Lynch).

The one more important question for the topic is: how culture and society influence these mental images? This question is quiet important because the imagination and long time memory are the higher mental functions and culture plays an important role in their formation. The theories of C.G. Jung and M. Cole can shed some light on the topic.

C.G. Jung's analytical psychology presents the idea of collective subconsciousness. It represents the collective prehistoric experience of the specie and makes a basement for the all conscious activities of human beings. Ass well collective subconsciousness creates some fundamental scenarios or models for thinking and world understanding &endash; that could be proved by the same scenarios that are used by mythology and modern science. Example: dynamic model of chaos and order used in cosmological myths and its presence in the theory of chaos and order by I. Prigogine. The content of collective subconsciousness is made from archetypes &endash; the "ideal, universal forms" that seek to express (realize) themselves through the conscious activities (both individual and collective). The archetypes could be common for the all human kind or just limited to specific culture. Because the higher mental activities are based on subconscious processes, it is quiet probable that "cultural" archetypes can influence the imagination of the world and of a single city as well.

M. Cole's theory can put some more light on this problem. The key figure in the theory of cultural &endash; historical psychology is an artifact. Artifacts are a wide range of cultural creations &endash; from work tools to symbols, models and schemes (material and ideal). It is some kind of "outer brain" or collective consciousness that represents historical experience of cultural society. The interpersonal contents presented by artifacts become intrapersonal when a child grows within a culture. They are intrapersonalized by the help of verbal or visual symbols. So the content of artifacts is closely related to the higher mental activities and it affects the imagination, thinking and long time memory within an individual mentality. In such a case it is logical to deduct that conceptual perception of an environment is highly influenced by culture.

The additional important conclusions that are made in the context of the theories of M.Cole (cultural &endash; historical psychology) and C.G.Jung (analytical psychology) are following:

• There exists a high probability that culture makes an influence on the standard of preferred environment by supplementation of culturally determined images and schemes of an ideal city &endash; some kind of an archetype (we are "instructed" what and how to imagine by culture).
• Despite the probable significance of the archetype it is believable that these cultural schemes could not be used as a final and desired model for creation and evaluation of the preferred urban spaces because:
  • The city is too complicated and its model is formed by many factors that are not under control of planner often.
  • The common mental image of city could be researched and formed just with some degree of probability (quiet low).
  • The cultural images often are to simplified, symbolic and schematic to be applied in the urban planning as the final models.
• The objective of town planning should be not a final spatial model of city absolutely similar to the "ideal" and preferred urban environment but to make it more similar to the cultural image comparing to the present situation. Creation of the preferred urban space should be a permanent process.

A lot of more detailed theoretical and practical research should be done for the test, further development and implementation of these theoretical discursive findings into practice. The most actual topics for the further research:

• Relations between culture and the criteria of preferred environment.
• Images of preferred urban space in a specific culture.
• Importance and possibilities of both the methods of spatial planning and spatial substructures(as the green structure) in creation of the preferred urban environment. This research should go from "bottom to top" &endash; theoretical conclusions should be made on the base of practical study. This method will give the best and the most obvious results.

GREEN STRUCTURE and PREFERRED URBAN ENVIRONMENT (Kaunas case)

Here the green structure is understood as a system of green areas in this paper. Green areas &endash; open spaces with natural or natural-like landscapes. The processes that support these landscapes are going in natural way within them as well. The term "system" means that the structure is able to perform some additional functions if comparing to a single green area &endash; for example: creation of preferred urban environment (at the whole city scale).

Preferred environment &endash; psychologically acceptable environment that do not produces an environmental stress. This term could be applied to both visually and conceptually perceived environments. Creation of the preferred urban environment is a new task. It becomes very important in the context of creation of a sustainable city &endash; instead of looking for the preferred environment outside a city we should try to create it within an urban area.

Should the green structure be considered as probably enough useful for the purpose mentioned above? Yes if we agree to the following statements: a) a typical urban environment is to stressful; b) the green areas have totally different both the spatial characteristics and the emotional or psychological content if compared to the urban areas. This is especially true if we have in mind the traditional attitude to the nature in the western culture &endash; it is an opposition to the city. On the base of both the statement "a" and the statement "b" it is logical to conclude that the green structure can help a lot in creation of preferred urban environment.

The next question: how (from the point of view of a spatial planning) can the green structure make the urban environment more preferred and how it should be planned to perform such a function? It is a wide field for investigation but some preliminary conclusions and guidelines could be made on the base of a specific case analysis. Such the analysis was done for Kaunas. The selection was influenced by the specific urban situation. Kaunas is a typical soviet town with a big and monotonous areas that are filled up by the typical many-flat houses and the problems of psychological acceptance are very actual there. In such a situation the possible usefulness of the green structure should be seen very clearly.

The analysis for both finalization of the hypothesis and more detailed conclusions is made in the following key - steps:

• Determination of the image of Kaunas. The city image is understood according to the theories of K.Lynch. The results of this part of the analysis are not of direct interest of this topic, but they have an applied value. If the green structure will be planned &endash; such a determination of the city image in a specific situation will be needed.
• Evaluation of the possible role of the continuous green structure and its elements (as green belts, parks, etc.) for the key features of preferred environment at the level of a whole city image.

Determination of the public image of Kaunas. The main practical and methodological problem: inconvenience of both the classical methods for the image finding in the context of limited time and human resources. The problem could be solved if the principle "support and deny" will be used for a simplification of the image finding process. The main point of the simplification is based on the fact that the elements of the city image interact with each other. A one element can support or deny an another one &endash; it depends on a spatial relations between potential parts of the image. The elements support each other if the spatial relations between them correspond to some "obvious" imagined schemes. These schemes could be found in the papers of K. Lynch. The example of such the scheme: it is obvious for us that landmark stands in the center of a district of the image. If we see a high unique building then we imagine that it is in the center of some area.

This principle is not able to help to find the spatial transformations of the image and its parts (if compared to a real physical environment), but it can help to determine the final structure (with high enough probability) and to analyze the features (important for the discussed topic) of the image that are based on the interaction of the elements (as we will see later).

According to what was said above, the image of Kaunas is found in the three steps:

• Determination of the few most significant elements (a backbone or frame) of the image;
• Determination of the all potential elements of the image;
• Analysis of "support & deny" relations between the potential elements of the image.

The main characteristics of the image (presented in the picture):

• The image is fragmented &endash; it is possible to state with a high probability that some parts of the image will not be imagined as parts of the city
• Domination of the one center &endash; district.
• The spatial characteristics of districts are very similar &endash; it is a result of soviet urbanization.
• The districts are formed by boundaries and in many cases some landmarks &endash; it is true because the districts are very similar to each other and only boundaries and very significant landmarks will let us to imagine some similar areas as different districts of the image
• The net of pathways plays a vital role in the integration of the image &endash; it is so because of the monocentric structure of the image.

Can the continuous green structure make this city image more preferred and how it can do that? The first step in the search for the answer of this question is to see how weighty can the green structure bee in the all public city image &endash; is it worth to analyze its role more thoroughly or not? Fig.2. shows what parts of the city image are formed by the green areas of Kaunas. Two things are seen very clearly in the picture: the green areas are spread all over the image evenly and about 1/3 of the whole image is "made" of these areas. These facts direct us to the final objective of the study - to understand and estimate the possible role of the green structure for the assurance of key - features of preferred space: no visual stress production, legibility, coherence, complexity and mysteriousness. Very important premise &endash; each environment should have these features more or less expressed, in other case &endash; such environment will not be conceptually perceivable. This fact could be illustrated by the following example: legibility is one of the key-features of the preferred environment; according to K. Lynch's definitions we can say that if an urban environment is not legible &endash; the city image could not be created and a city could not be conceptually perceived.

The analysis of the role of the green structure (in creation of the preferred environment) is carried out in the following steps:

• the feature is analytically described in the terms related to a structure of the city image;
• determination which parts of the image play an essential role for the creation of the feature
• search for an obvious correlation between the elements of the image and the green structure.

No visual stress production. This feature of a spatial environment means that visually perceived space "isn't either too diverse or too monotonous". The criteria for such an ideal space depend on the neurophysiological characteristics of the human nervous system. This feature of environment is related with the directly visually perceived environment and should not be applied to the image of city. Despite that this feature should be considered when the preference of a visually perceivable environment is analyzed.

Legibility. It is "the inference that one can explore an environment without becoming lost". From the point of the city image it's the possibility to find, notice, perceive, distinguish from the context the potential elements of city image. If environment is not legible &endash; the common city image could not be created or imagined. This feature is applied to the physical environment and visually perceived space as well, but not to the image.

Coherence. "It's the sense that all parts of (conceptually) perceived environment make a one unit". From the point of the city image coherence should depend on the three characteristics of the image (these characteristics make an essence of perceivable integrated order &endash; in opposition to unperceivable disintegrated chaos):

• Continuousness of the image. In Kaunas case &endash; it depends on the network of ways very much because the way is a place where the "creation" of the city image starts &endash; people see and remember the most distinguished elements of an environment while they move through a city. These memories are used for "creation" of the mental city image later. Greenbelts can play an important role in creation of the more preferred environment in Kaunas case. For example &endash; by making a clear connections between the center and the authonomous districts of the image.
• Clear separation of parts (districts) of the image. The green slops of the rivers are very important for separation of the similar areas in Kaunas. Without these slops- boundaries there would be just a one big district in the image of Kaunas.
• Hierarchy. Role of the green structure isn't very big in this case directly, but the green slops make a great visual background for some very important landmarks in the image of city. In their turn these landmarks are very important for perception of the center of the image.

The culture can make an influence on the kind of hierarchy and the ways of integration what will be more preferred that the other but it is the theme of another research.

Complexity. "Environment is complex if it contains enough variety to make it worth to learn about". In the term of city image it could be described as diversity of types of elements in the image. The properties of human perception should be taken into consideration when the complexity is researched. We construct the mental image of environment from the pairs of oppositions. It is the fundamental feature of perception. Environment without the perceivable oppositions will be not complex. The city image should be made in the same way and its diversity depends on the clear presence (necessary condition) and number of the pairs of oppositions.

Culture can determine the kind, number and spatial relations between the oppositions. The role of the green structure could be very important here because, according to Jacques le Gof, nature is understood as a natural opposition for urban environment in the European culture.

There the green structure makes the image more complex by forming a few, quiet important green districts in the image of Kaunas.

Mysteriousness.It is "the prospect of gaining more information about environment". Mysteriousness of the city image depends on two things. The first one is a permanent ability to discover something new in a city &endash; to find some kind of "terra incognita" in the image. The second one is a representation of an unpredictable "chaos" (with a proper emotional attitude to it) as an opposition to a well known and predictable order. It could be produced in two ways: both as a one part of the perceived spatial oppositions and as chaotization of the structure of image. An understanding and symbols of chaos depend on cultural influence very much. The greenstructure helps to produce these effects by creating a green district in the image of Kaunas.

Conclusion: The case of Kaunas, shows that greenstructure can play the significant role in creation of more preferred image of city. It is important for the assurance of the all key &endash; features that are "felt" through the image of city.

Examples what the green structure can give:

• Green boundaries for the separation and creation of the districts in the city image (coherence of the image);
• Greenbelts for the bigger integration and continuousness of the image (coherence);
• Green districts for the bigger complexity and mysteriousness of the image;
• Green background for the landmarks ( better legibility of environment and coherence of the image).

The Table 1 through consecutive order - links the planned types of green areas to the concrete features of the preferred environment. The features (coherence, complexity and etc.) are listed in the first column. The special characteristics of the public (mental) city image that are extremely important for the special feature are listed in the second column. The third column relates the parts of the image to the three simple meta-types of the green areas &endash; as parts of physical urban townscape. These types are determined on the base of percept simple form, size and possible position of perception (if it makes some difference), because it is extremely important for "creation" of what element of the mental image will a green area be used. These types could be the following:

• Line. Lines could be perceived from within (as green belt for pedestrians) or from outside (as green wall).

• Area or square. It is perceived as any large, autonomous geometrical form. The most important thing is that it is large enough if compared to the other potential elements of the image of the same kind. For example: it could be park or forest &endash; potential district of the image.

• Dot. It is a small green or blues island within an urban landscape.

• The last column links the meta-types of green areas with types of the planned and designed urban green areas. The planned urban green areas are classified according to the main purpose of land use. There could be the three main purposes of land use: building, open space and infrastructure (areas of transportation mainly). Accordingly the green areas can be formed as:

• Parts of a bigger plots (school, kinder garden, etc.). These green areas are perceived as a "green dots" within an urban environment. These areas are inseparable from the main function of the plot.

• Autonomous green areas as parks, gardens, public gardens and etc. These areas could be divided into the two groups: open for public use (as mentioned park or gardens) and with limited public use (as zoo, botanical garden and etc.) the autonomous green areas could perceived in both ways as dots and autonomous squares &endash; it depends on a size of the green area if it is compared to a size of neighboring urban areas. One exception (very important in Kaunas) &endash; green slops of river valley. These areas are perceived as "green line" and have limited public access due to the special physical characteristics.
• Green areas that are located in the territories of infrastructure or are used for any kind of transportation. It could be a green belt beside a road, green alley, bank of a river and etc. These green areas are perceived as "green lines" or "green walls".

The model presented in the Table 1 is based on Kaunas case only. It aims to give some ideas and starting points for urban planners in creation of preferred environment and does not pretend to the final summary or conclusion. The model is simplified a lot as well but it is in the nature of modeling. Besides &endash; in this way it gives a more clear understanding of relations between the planned specific urban green areas and the features of preferred environment.

RESUME

On the base of presented discourse it could be concluded (with a high enough probability) that the green structure can help significantly in creation of the more preferred urban environment. This need is especially actual in the context of sustainable urban development. The term "green structure" means the system that is performing some additional functions if compared to a single green area. In such a case the creation of the more preferred totality of a city could be one of the additional functions of the urban green structure. The experience and results of Kaunas case confirm the main thesis of this paper and could be used as the preliminary guidelines or inspirations in an urban planning.