عنوان مقاله [English]
The structure and shape of the historic core in many ancient cities of Iran were mainly disregarded in urban development trends. This has led to some problems of inconsistencies with new physical changes, lack of appropriate link with existing structural network and spatial isolation. The main structure of a city is a set of interrelated and continuous urban spaces encompassing the essential elements and main activities of the city. Understanding this structure requires a thorough analysis of all aspects of the phenomenon. Among the theories dealing with the urban spatial structure, the space Syntax theory has useful capabilities to address the problems. In the past decades, Urmia has experienced major changes in its traditional structure and also the historic core of this city like many other cities. Under the influence of hasty actions, this has undergone numerous difficulties. The objective of this paper is to identify and analyze the growth process of urban development of Urmia and its structure. Thus, we have addressed the effects of contemporary physical changes on the spatial structure of the historical district and the relationship between key elements of the historical structure to investigate the spatial coherence. We have used the Space Syntax theory to analyze the structure and spatial configuration of the city. According to selected parameters for analyzing the urban structure during various periods, the main goal is to study the changes of values and the performance of historical texture through the analysis of the elements of urban spatial structure and the output spatial parameters of this theory.
This is a descriptive, quantitative and a comparative research in methodology. In this study, the Urmia city and its historical district is analyzed with the Space Syntax method using AutoCAD, Depth map and ArcGIS. In order to study the spatial structural changes of Urmia city and its impact on the spatial structure of the historic core of the town, based on available documents and maps, four main periods of physical evolution of the city, i.e., the years of 1933, 1976, 1994, 2016, have been considered for analysis of its structure through the space syntax theory. After the parameters and analytical maps of the space syntax were analyzed by the comparison of the periods, validity changes have been assessed. These are considered as the most important concepts in this method to study four factors of coherence and coordination of the structure of the historical district, assessment of value and importance of historical orders and its main elements and the manner of distributing activities in the range.
Results and discussion
The results of this research have revealed that the lowest deviation and the highest amount of affiliation and thus urban coherence is related to 1933 following physical changes of the city with reduction of structural integrity. The values of urban affiliation in historical range during the four periods indicate that the average historical context of the city is less than that of the city affiliation. This implies that the internal structure of this area has not been related to these axes. The changes in the values of the inter-connection of the main historical orders have been studied for structural analysis of the main axes.
The spatial physical value of the axis is degraded to inferior position, because both the average value of the interconnection of each axes and also the average difference between the axes are declined compared with previous periods. In the subsequent analysis, public spaces containing historical market and the main fields of the historical core (The Velayat-faqih and Ayalat square) and the central mosque of the city have been considered as the main religious element in the texture. Integration of factors shows that until 2016, the extent of the interconnection of the main historical spaces has been reduced as one of the major city activity centers. The next criterion examines the overlaps of the most integration axes with the active and attractive users of the cities and their relationship.
According to the results of this research, it was revealed that the performance and historical coherence and its relation to the structure of the city have been reduced under the influence of physical changes over the time. The internal structure of this range could not be mingled with the overall structure of city. A large part of identity values and physical texture affected by these changes have been lost. The spatial continuity of main elements and the functional significance of historical orders have been weakened under the influence of the changes. This indicates that the rapid physical changes in the recent years had negative effects on the spatial structure of historical range of Urmia city.