Tehran Urban Development Planning with a Landscape Ecology Approach (Case Study: Municipal District 22, Tehran)

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1 Journal of Landscape Studies 3 (2010), Received: 19 April 2010; Accepted: 13 May 2010; Published online: 15 May 2010 Journal of Landscape Studies Tehran Urban Development Planning with a Landscape Ecology Approach (Case Study: Municipal District 22, Tehran) Shadi Barati*, Morteza Rahbar, Mahdi Shaibani Landscape Architecture Department, Faculty of Architecture and Urban Planning, Shahid Beheshti University, Tehran, Iran. Abstract Throughout the last two centuries Tehran has faced rapid urban growth. This rapid growth has led to unplanned urban development, causing major environmental problems and a severe lack of human contact with nature. It is therefore crucial to devise a comprehensive urban plan with a new landscape ecology approach to bring nature back to the human realm for the future development of the city. In this study, municipal district 22 has been taken as a case study for the future extension of the boundaries of Tehran. This municipal district has a great capacity for urban development. In order to achieve suitable urban planning in this zone, an interconnected system of green spaces is planned which will provide an ecological network for the city according to landscape ecology principles. Planning this green network has been considered on three different scales with regard to a hierarchical approach toward urban landscape: regional, municipal and local scales. The regional scale takes the main natural ecological resources into account. The municipal scale considers local parks and green thoroughfares as the main components of the ecological network with regard to the potential opportunities of the urban network. Finally, on the local scale, extensions of the proposed ecological network penetrate into the heart of the urban fabric and especially into residential spaces. The study of municipal district 22 aims to provide an insight into the main principles of Tehran urban extension with a landscape 1. Introduction ecology approach. This zone is considered as a case study. However, it is has similarities with other zones than the suburbs of Tehran, and the principles could also be generalized as a model for other zones. Conservation biology is a multidisciplinary scientific field that Key words: Urban landscape planning; Tehran urban development; Landscape ecology approach; Ecological network; Hierarchical approach. 1. Introduction Iran is becoming an increasingly urban place. Many cities in Iran are experiencing rapid urbanization, mostly in the form of unplanned development. This rapid and unplanned urban growth has caused major environmental problems and an increasing distance between people and natural spaces. As a result, concern about environmental quality and the long-term livability of urban areas is now a driving paradigm for planning professionals. Within this paradigm, the incorporation of ecological knowledge is regarded as strategic to protect and improve urban environments. The principles of landscape ecology would therefore provide a theoretical basis for sustainable urban development which will bring the natural processes back to the human realm. In other words, there is nowadays an essential need for a conceptual framework for urban development planning that is based on scientific ecological approaches. The science of landscape ecology * Corresponding autor; Shd.barati@gmail.com 65 Available online at:

2 would be integrated into the art of planning and designing the human environment. Hierarchical landscape planning is a model used in landscape ecology planning. It uses multi-scale consideration of landscape resources for a studied region. This model has been used by many landscape planners and theorists in the last four decades. The first prominent book on this theory, Hierarchy Perspective for Ecological Complexity, was written by Allen and Starr in However, the application of this theory is still far removed from the theory itself. A historical look on Persian urban planning reveals that Iranian architects and planners had a multi-scale planning approach very long before it was mentioned by recent theorists. In the Safavid Period ( A.C), the architect Sheikh Bahaie planned the city of Isfahan in a multi-scale manner. On the regional scale, he designed and planned the city in such a way that the Zayanderood River formed the main green structure of the city. On the second scale, he derived small branches of water from the River Madies, which penetrated through the urban textures and brought the greenery and a water body to these areas. At this stage there was a green network throughout the city of Isfahan. And on the third scale he proposed green streets and valleys in the city for neighborhood accessibility. By this kind of multi-scale planning Sheikh Bahaie transformed the city of Isfahan from an arid area to a sustainable green city. Nowadays, this model is far from being applied in the development and planning of the cities. Tehran, the capital city of Iran, is the largest city in the Middle East. Today, Tehran is confronted with rapid urban growth towards its suburbs. This paper studies the urban development of Tehran and proposes the hierarchy landscape planning model as the main development structure for future extension of the city. The main goals of the study are to: -Incorporate theoretical principles of landscape ecology into urban landscape planning -Reduce Tehran's environmental problems -Protect prominent ecological resources and processes throughout the urban region -Respond to human needs for intimate contact with nature -Rehabilitate the multi-scale planning from the history of Persian urbanism into the modern city -Introduce a framework for ecological landscape planning based on a hierarchical approach 2. Study Area Tehran is a city of 7 million in an urban region of 12 million inhabitants. As the capital city of Iran, it functions as a centre of gravity for the economic, political and cultural affairs of the country. Tehran is a modern city, with high rise buildings and a network of motorways, with all the associated problems of traffic congestion, environmental pollution and housing shortage. This urban landscape is primarily a result of the city s growth and development during the second half of the twentieth century. A brief investigation of the city today shows that modernization of the urban space has continued after the revolution, more or less along the same lines that had been set before the revolution. Although interrupted by wars, revolutions and periods of economic slowdown, Tehran s urban form today is the result of five centuries of urban development, and more than 150 years of modernization, which can be traced in several periods of intense urban development and renewal. The rapid urban growth of the second half of the twentieth century, therefore, was largely dependent on the earlier stages of development and modernization, which paved the way for subsequent development and expansion (Figure 1). Due to the landform and geomorphological aspect of Tehran, the city tends to extend westwards. The northern and eastern part of the city is bounded by mountains, and the southern part is bounded by farms. Another major reason for the westward urban extension of the city is its air quality. The prevailing wind direction in Tehran is from west to east. We can always see that the western parts of Tehran (especially the northwest of Tehran) have better air quality than the central and eastern parts. Tehran is divided into 22 municipal districts. District no.22 is the largest urban district, and is located in the north west of the city (Figure 2) Municipal District 22 With an area of about 6000 hectares, twice the size of any other region of Tehran, Region 22 has a special climate and geographic situation. Its extremities are the Kan floodway to the east, the 66

3 Figure 1. Tehran Urban Growth Graph ( ). Tehran-Karaj freeway to the south, the end of the Vardavard area to the west (Kilometer 30 of the Tehran-Karaj freeway) and the Alborz range extends up to an elevation of 1800 meters to the north. Most of the lands situated in this region, apart from the approved built townships, contain unutilized and agricultural land in the form of big parcels. Region 22 of the municipality borders on regions 21, region 5 and Karaj County. According to the latest census (2006) it has a population of about , and there are about households scattered in 1000 acres throughout the region. The region is unique in terms of green area per capita, about 272 square meters, low population density and calm traffic movement. It is the green belt area of Tehran, known as a clean air arena of the city with many forest areas and recreational sites. Figure 2. Tehran Municipal District

4 , , , , , , , , , , , , , , , , , , , , ,890 56,020 No , , , , , , , , , , , , , , , , , , , , , ,840 No Table 1.The population of 22 Municipal Districts of Tehran. Table 1 shows the population of Tehran's municipal districts. Due to its size, district 22 (Figure 2) has a great capacity for urban development. The predicted population for the region, according to the master plan, is , which in future development could increase to 1 million. Due the importance of landscape in promoting quality of life in urban contexts, the urban development of the district should be based on the landscape ecology approach. However, the question is what kind of landscape planning model could help us to fulfill this goal? The best answer to this question is considered to be through hierarchical landscape planning. Hierarchical landscape planning will be defined in the following sections. 3. Hierarchical Landscape Planning Landscapes are increasingly regarded as complex systems composed of a large number of spatially heterogeneous components that interact in a nonlinear way and exhibit emergence, selforganization and adaptive properties through time (Waldrop, 1992; Prigogine, 1997; Kay and Regier, 2000; Wu and Marceau, 2002). An important characteristic of complex systems is that their hierarchical structure is defined at different critical levels of organization where interactions are stronger within levels than among levels, and where each level operates on relatively distinct temporal and spatial scales (Simon, 1962; Allen and Starr, 1982). Therefore, scale is central to the realization of hierarchy and the organization of landscapes (Levin, 1992). In general terms, a hierarchy may be defined as a partial ordering of entities ; thus hierarchies are composed of interrelated subsystems, each of which is made of smaller subsystems until a lowest level is reached. Within the formal framework of hierarchy theory (Allen and Starr, 1982), a hierarchically organized entity can be seen as a three-tiered nested system in which levels corresponding to regional, municipal and local scales are considered. The planning method for District 22 is most appropriately characterized as a hierarchical systems approach. In this study, the analysis and landscape planning of this region is considered on three scales: 1) regional 2) municipal 3) local 3.1. Regional Scale At the present time, the regional scale seems to be an issue of growing importance in a much larger context than that of landscape architecture research. The transformation of towns and cities to urban regional landscapes went on throughout the 20th century, starting with the trends of suburbanization, garden cities, etc., at the beginning of the century. The scale of the urban region is increasingly conceptualized and discussed by researchers as an empirical phenomenon. On the regional scale, urban landscape is 68

5 considered beyond the city boundaries. In other words the city is investigated as a part of a wider region and in relation to the greater natural environment from a holistic point of view. As a result of taking a regional perspective on the urban landscape, the extensions of the ecological processes related to the greater environment are considered in the urban environment. The science of landscape ecology, which links ecological processes with landscape and spatial configurations, guides the ecology-based attitudes of urban landscape planning on a regional scale. According to landscape ecology principles, the vital presence of natural ecological functions and processes in urban regions may be achieved by means of natural matrix penetration and connectivity throughout the city. Landscape fragmentation due to urban development poses a threat to environmental integrity. Therefore the main ecological corridors and the patches of landscape that bring the ecological values from the natural environment beyond the urban boundaries should be taken into consideration in the future planning of the city. In this way the nature and its processes penetrate into the human realm and into urban areas. This kind of perspective on the urban landscape on the regional scale is considered in the landscape planning of the municipal districts. Municipal District 22 is a developing urban area which is in direct contact with the natural environment. Thus the extensions of the ecological network of the natural environment through this urban area play an important role in promoting the urban environment. District 22 has five major natural ecological resources. Two of them are classified as water bodies and the other three as green bodies of the zone. The green bodies are: Latmal Forest, located in the northern part of the district, Vardavard Forest, in the western part, and Chitgar Forest, in the southern part. The water bodies are: Central Lake, and the Kan River, located in the eastern part of the district (Figure 3). The Kan River is the biggest river in Tehran and an average of approximately 70 million cubic meters of water flow from it each year. These main natural resources of the district play an important role in Tehran's environment. They should therefore be considered in Tehran's urban context. In the landscape ecology planning of district 22, three main steps should be taken into account on the regional scale. In the first step, urban development should be planned in a way that can protect these natural resources. In the second step, landscape planning should try to enhance the natural aspects of these sites. And in the third step, urban development plans should provide easy access for Tehran residents from different parts of the city Municipal Scale On the municipal scale, the ecological network that has originated from the natural environment is considered inside the urban limits and in direct contact with the built environment. In other words, the main framework and backbone of the ecological structure that has been determined on the regional scale extends inside the urban fabric. According to landscape ecology principles, the connectivity of the ecological network should be maintained throughout the urban fabric. Accordingly, an interconnected network of green spaces is proposed on the municipal scale which is compatible with the urban network. The building of the urban green space system must be dependent on the relations within the regional ecological network. Otherwise, within the internal city, green spaces become a kind of island surrounded by man-made structures and, at the same time, outside the urban land the energy and the biological flow of the natural environment cannot enter effectively into the main urban area. Consequently, creating connections within the main framework of the ecological network would shape a green network that enhances the environmental conditions of the city. Urban networks are potential opportunities for developing green connections between natural ecological resources. In other words, green spaces of streets, highways, urban squares, urban plazas, as well as public green spaces such as local parks could provide opportunities for rehabilitating the city s green network. In this way the subordinate branches of the ecological network which penetrate into the heart of city are established and an interconnected network of green spaces is organized within the urban fabric. There are major freeways and highways in district 22. These thoroughfares are the main transport structure of the district and they have 69

6 Figure 3. District 22 Landscape Ecology Planning (Regional Scale). great potential to be transformed into green networks. In Tehran there are a few examples of thoroughfare greenways, but none of them have been planned as a green network. Only parts of them are to some extent greenways. Figure 4 shows the Modaress Highway in the Abbasabad city quarter. This part of the Modaress Highway is one of the most famous thoroughfare greenways in Tehran. forming a continuum of green bodies. These green routes provide people with access to open spaces close to where they live, and link natural and urban spaces into a great circulating system. There are other ecological, aesthetic, psychological and cultural benefits of greenways. Hemmat, Hakim and Azadegan are the main highways in the district. The Tehran-Karaj Freeway passes from the southern boundary of the districts and connects Tehran to Karaj and the suburbs. These routes form the main structure of the greenway network of the district (Figure 5). Local parks are other important ecological resources that should be planned in the municipal district. These parks are planned for residents living within a 5 km radius from them. Three local parks are planned for the development of district 22. As there is easy access to the nearby green bodies in the western part of the district, no local parks are needed on the municipal scale. (Figure 5) 3.3. Local Scale Figure 4. The Modaress Highway as a thoroughfare greenway. In district 22, the highways should be planned as green networks for two main purposes: as a green connection of natural resources, and as urban parks On the local scale, extensions of the general green network of the city cater to the daily need for contact with nature. Burgess et al (1988) found that the most valued open areas are intimate and familiar spaces that play a part in peoples daily lives, rather than distant areas. The need for green 70

7 Figure 5. District 22 Landscape Ecology Planning (Municipal Scale). spaces near to home can be met if there are such spaces within 400 meters, or within 10 minutes on foot. Quantitative criteria have been adopted in some countries to foster the penetration of green spaces into the built environment of cities. The social functions of the ecological network therefore play an important role on the local scale, enabling immediate contact between citizens and nature. Moreover, green spaces on a local and neighborhood scale encourage informal community meetings and social relationships. On the other hand, the ecological benefits of the green space network on a local scale are also significant. Green spaces can enhance the local environmental situations and contribute to suitable microclimates. In addition, extensions of the green space network provide connectivity and continuation of the ecological network all over the city, especially in residential areas. Open spaces belonging to public buildings, green roofs, green walls, private residential open spaces, pedestrian routes, valleys and neighborhood parks provide Figure 6. District 22 Landscape Ecology Planning (Local Scale). 71

8 potential opportunities for planning the ecological network on the local scale. In this way, nature is experienced in everyday urban landscapes, and a kind of intimate contact with natural processes is provided for city dwellers. Some neighborhood parks are planned for the district on a local scale. These parks are located in such a way that there is easy access in less than 10 min from residential sections. These local parks are small green spaces that respond to the minimum human need for contact with nature. They also provide opportunities for recreation and cultural activities (Figure 6). Layout "A" shows one of the residential sections of district 22. In local scale planning, the green space should penetrate throughout the passages and valleys. This kind of planning contributes to the formation of a continuum of green spaces into the very small parts of the district. In this layout, the green passages are planned as residential green belts. They play the role of green corridors, in conjunction with the green patches of the neighborhood parks in the local scale ecological network (Figure 7). Figure 7. Layout "A" (Local Scale Planning). 4. Conclusion A major issue interrelated with unplanned urban sprawl within the urban area of Tehran is the lack of ecological integrity and an increasing distance between people and natural phenomena. Accordingly, the scientific principles of landscape ecology have been taken into consideration as the theoretical framework for the art of planning the urban landscape with a view to integrating nature and the human environment. Multi-scale consideration of landscape planning in a hierarchical structure incorporates the theoretical approach of landscape ecology into the practical realm of planning and designing. Thus it is essential to reinterpret the hierarchical planning experience of the traditional Iranian city, taking into account the recent literature on landscape ecology. According to the principles of landscape ecology, the vital presence of ecological functions and processes in urban areas can be achieved by the means of ecological matrix connectivity throughout the city. Consequently, a proposal has been made to develop an interconnected green network that will meet the aspiration of ecological integrity throughout the urban area. Municipal district 22 has been considered as a case study for exploring the general principles of the proposed ecological network in greater detail. For the purposes of a hierarchical and three-tier system of landscape planning, the main backbone of this ecological network has been established on the regional scale, taking into consideration the natural ecological resources of municipal district 22, which are supplemented by the natural environment beyond the urban boundaries. On the municipal level, the priority is to create connections within the main framework by taking advantage of potential opportunities of the urban network in the district. Finally, the subordinate extensions of the network have been shaped on the local scale, providing opportunities for residents to have intimate contact with nature. By superimposing the three layers on different scales, an integrated ecological network originating from the natural environment beyond the urban boundaries penetrates into the heart of the city (Figure 8). It seems that the contribution of the ecological network can be established from different perspectives. Multiple socio-ecological functions are served by an integrated green network on different scales, which are the main ingredients of a livable city. As a result, the method used in this study in classifying the development of an 72

9 Figure 8. District 22 Landscape Ecology Planning (Regional, Municipal and Local Scales). interconnected ecological network into three levels can be generalized. Indeed the method may provide a way toward a close-to-ideal sustainable city by incorporating scientific ecological principles into the art of designing in the realm of landscape architecture and planning. of Urban Growth in Tehran, Bauten im Laufe der Zeit, VINI, TU-Berlin. Jim, C.Y., Chen, S.S Comprehensive greenspace planning based on landscape ecology principles in compact Nanjing city, China, Landscape and Urban Planning, 65: References: Allen, T.F.H., Starr, T.B Hierarchy Perspective for Ecological Complexity, University of Chicago Press, Chicago. Department for Transport, Local Governments and the Regions Green Spaces, Better Places: Interim Report of the Urban, Green Spaces Taskforce, London. Prigogine, I The End of Certainty: Time, Chaos, and the New Laws of Nature, Free Press, New York. Levin, S. A The problem of pattern and scale in ecology. Ecology, 73: Kay, J., Regier, H Uncertainty, complexity, and ecological integrity: Insights from an ecosystem approach. In: P. Crabbe, A. Holland, L. Ryszkowski and L. Westra (Eds.), Implementing Ecological Integrity: Restoring Regional and Global Environmental and Human Health, Kluwer, NATO Science Series, Environmental Security, pp Waldrop, M.M Complexity: The emerging science at the edge of order and chaos, Simon and Schuster, New York. Burgess, J., Harrison, C.M., Limb, M People, parks and the urban green: a study of popular meanings and value for open spaces in the city. Urban Studies, 25: Rahbar, M., Shaibani, M Tehran Riverfronts Rehabilitation (Case study: Kan River), Green Culture in the City, IFLA APR 2009, Incheon, S. Korea. Madanipour, A Early Modernization and the Foundations 73