Document Type : Article extracted From phd dissertation
Department of Human Geography, Faculty of Geographical Sciences, Kharazmi University, Tehran, Iran
Department of Social Planning, Faculty of Social Sciences, Allameh Tabatabai University, Tehran, Iran
A B S T R A C T
The spatial structure of a city has a key importance among its tangible and intangible elements. Because it can support all activities of residents and influence these activities. Analyzing the mutual relationships between spatial forms and urban functions is one of the most important methods of evaluating the spatial structure of cities, which is often neglected in existing studies. Based on this, the current research aims to analyze "urban space configuration patterns" and "functional cores" as the formal and functional dimensions of the city's spatial structure, which is followed by a case study of the Tehran metropolis. By using a combined analysis method based on the theory of space arrangement, the evolving spatial structure of the Tehran metropolis was explained. "Cohesion" and "readability" indices were used to analyze space configuration, and "population", "employment" and "land use" data were used to analyze functional cores. Also, the spatial correlation between the variables at the regional level was calculated based on the "geographical weighted regression" method. The obtained results led to the explanation of some features of the spatial structure of the city of Tehran, including "center-periphery interconnectedness pattern", "natural movement pattern" and "function core concentration patterns". Also, a positive correlation was observed between interconnectedness and spatial concentration of functional cores, which can be interpreted both in terms of urban areas and separately for each of the functions. The final result was that the transition from single-core construction to multi-core construction is happening slowly in the city of Tehran, and the result of the current transportation and traffic policies is to create a kind of inequality between different parts of the city in terms of movement and access, despite the relative organization of traffic.
The spatial structure is of crucial importance among its tangible and intangible elements. Because it can support and influence all the activities of the residents. Analyzing the interrelationships between spatial forms and urban functions is one of the essential methods of evaluating the spatial structure of cities, which is often overlooked in existing studies. Accordingly, the purpose of this study is to analyze "urban spatial configuration patterns" and "functional cores" as formal and functional dimensions of the spatial structure of the city, which a case study of Tehran metropolis has followed.
Evolving spatial structure of Tehran was explained using a combined analysis method based on space layout theory. UCL Depth Map software was used to achieve a variety of composite analysis indicators using axial mapping. Combined features for measuring spatial configuration included "integration", "connection", "selection", "resolution" and "total relationship with the component". In addition to these indicators, including land-use maps and population maps in the Arc GIS software environment. After this step, to determine the spatial distribution of each function using spatial analysis methods such as Kernel Density, urban core maps were prepared. Based on this, the connection between integration and connection of communication networks and urban cores can be interpreted. Also, to investigate the spatial correlation between variables at the regional level, the geographical weight regression method was used.
Results and discussion
The results of this study led to the explanation of some features of the spatial structure of Tehran, such as "center-peripheral integration pattern," "natural motion pattern," and "functional cores concentration patterns." According to the results, the areas with the highest integration and connection were the location of urban cores. Also, a positive correlation was observed between integration and spatial concentration of functional cores, which can be interpreted both in terms of urban areas and separately for each function. On the other hand, the results of the present study indicate the incompatibility of the configuration model of Tehran with its dominant structure at the global level. Thus, high connectivity in the central core of many cities worldwide is synonymous with the possibility of the emergence of pedestrian-centered activities and the formation of a more human-scale space. On the other hand, in the city of Tehran, the opposite is accurate, and high-connectivity points have become the site of increasing car attacks, which is exactly the case with the city's problem areas. The results also showed that the original construction of Tehran, unlike many metropolises in the world, is still mono-core. Despite the excessive physical development of Tehran and the expansion of the borders of its urban area, the spatial structure of Tehran is still under the heavy influence of the central core on Enghelab Street (east-west direction) and Valiasr Street (north-south direction). In fact, it can be said that Tehran's transition process from a mono-core to a multi-core model is slow. But small sub-cores are likely to form in parts of the city. This mono-core model leads to overcrowding and traffic in the city center. But the lack of spatial planning policies has exacerbated the inefficiency of the central core, and all the problems of the last half-century in the central part of Tehran remain unresolved.
The final result of the present study was that the transition from a mono-core structure to a multi-core structure in Tehran is slow, and various policies have been implemented in the field of transportation and urban traffic to control and organize this mono-core structure. However, the most crucial criticism of these policies is that they prioritize the urban form and ignore the functional aspects of the spatial structure. Due to the dominance of the logic of natural motion based on the East-West model, the existing policies are more in line with this logic. The result of these policies, despite the relative organization of traffic, has been to create a kind of inequality between different parts of the city in terms of movement and access. Finally, while recalling the advantages of the spatial arrangement method in simultaneous analysis of social actions and spatial actions in the spatial structure of cities, it should be acknowledged that the purpose of analyzing urban configuration patterns with spatial arrangement theory is to identify key points of spatial structure as an integrated system, these points can be manipulated and strengthened so that the whole system (spatial structure) progresses to recovery. Given the limitations that the present study faced in terms of applying the spatial arrangement method to other topics, it is suggested that in future research, if there is the necessary data and information, issues such as daily travel pattern analysis, comparative study of the spatial structure of Tehran in periods and providing perspectives on transportation policy in Tehran should be considered by researchers.