Investigating the evolution of urban morphology with a physical-spatial approach (Case study: Ardabil city)

the city of Ardabil with its unique characteristics is an important example of the historical cities of Iran, whose physical analysis requires a more comprehensive research approach. This city was the cultural origin of the Safavids during the Safavid period and inspired the developments of other Iranian cities during this period. Developments that were rooted in a special culture that arose in Ardabil. The historical core of this city, like other Iranian cities, has been affected by the hasty actions resulting from industrial development and modernism, and it has suffered many problems. In addition, the worn-out tissues of this city have many complexities and physical-spatial problems in terms of morphology, which has caused the quality of life in this city to decrease. Therefore, the spatial and physical organization of this city requires a systemic and comprehensive approach and macro planning. Therefore, in the present research, the morphology and formation of problematic tissues in Ardabil city has been investigated and analyzed over time. In this regard, the current research seeks to answer the question, what are the changes in the morphology of Ardabil city during the periods (1373-1355) and (1373-present)?.

The present research is descriptive-analytical in terms of method and practical in terms of purpose. In order to analyze the morphology of the city of Ardabil, the analysis of space arrangement (co-linking) has been used. In this study, using the map analysis method, to investigate the morphology of Ardabil city and its changes and developments during the periods (1373-1355) and (1373-until now) in Ardabil city level using the parameter (interconnection as the main feature of the layout Space) has been done with the help of Autocad Civil 3D 2017 and Arc Gis software. In order to carry out the research process, it was first prepared using documents and manual maps related to the initial periods of growth and development in the municipality, and other maps were prepared with the help of the Tafadili plan map of Ardabil city with the application of physical changes related to each period, as maps The basis for drawing the axial line was done by considering the principles governing how to draw the lines in the studied courses with the help of AutoCAD software. Then, urban blocks were removed and the remaining linear layers were saved. In order to continue the work, each of the maps were reread using the Syntax Space plugin in the Arc Gis environment, which is one of the spatial arrangement analysis tools, and the spatial analysis parameter was performed by detecting the degree of connectivity, and the map and descriptive table were obtained from the results. The output was taken. In the continuation of the work process, in order to better understand the spatial analysis, by executing the commands related to the classification of the values along with the graphic display, the data output was saved in the form of tables, graphs and graphic maps, and these data were the criteria for descriptive analysis in different periods. it placed. The analysis was based on the evaluation and analysis of the correlation average and the correlation difference (difference between the highest and the lowest degree of correlation).

The morphological changes of Iranian cities are affected by historical events during a period of 43 years from the beginning of the contemporary century. The spatial structure of Ardabil city, like other cities in the country, has been affected by various factors, and with the passage of time and in the course of various developments that have occurred, it has gradually taken on the texture of the city as it is today. The old context of Ardabil city consists of six main neighborhoods of the city including: Gazran, Sarcheshmeh, Pir Abdul Malik Towi, Ali Qapo and Ochdekan, the first characteristic of these neighborhoods is their growth in relation to the market (city) which has expanded radially. But at the same time with the construction measures, the shape and growth and expansion of the city changed in such a way that with the entry of Bazar Street and the neighborhoods, they were split and the center of the neighborhoods is located at the edge of the streets. In addition, point elements such as banks, urban meeting places, cinemas and public libraries have caused the mixing and connection of similar uses with trans-neighborhood functions in some neighborhoods. This structure has formed the main body of the city fabric and has played an important role in the development process of the city until today. Due to having such a role, changes in the values of the spatial structure have been one of the influential factors in the changes in the morphology of Ardabil city.Period (1373-1355): The third period (50s) can be considered the period of physical growth and development without a pattern to the expansion of the checkered pattern function and the centralizing structure. In this period, along with the increase in thecity's population, the city's inner limits did not have the capacity for the additional population. Therefore, with the destruction of the fence, development and expansion continues towards the south and north. In this period after the Islamic Revolution (1960s), the conditions of the revolution and political developments such as the imposed war in most sectors, especially in the urban construction sector, became disorderly, and subsequently, the urbanization and urban development of Niaz also became irregular. The rapid growth of urbanization and the physical expansion of the city in this period continued strongly in the official form and within the framework of comprehensive, special and informal plans in the form of car settlements and peripheral structures. Among the most important features of this accelerated growth, we can mention the horizontal expansion of the city, the transformation of the physical structure, the excessive acceleration, the increase of the urban limits in unbalanced and balanced forms, and the ignoring of the city's internal capabilities and opportunities.Period (1373-present): The analysis maps of space layout parameters for the city of Ardabil in this period show that the east-west axis of Imam Khomeini Street of the city has the highest value of connection and connects the important points of the city to each other. After that, the north-south axis of Kashani street has the highest value of connection. In general, the main thoroughfares of the city are shown in the red color spectrum. Therefore, based on the theories of space arrangement, the probability of movement and activity in these axes is high. According to the Niaz connection map, the most accessible urban roads in terms of communication are the north-south axis of Kashani Street and the east-west axis of Imam Khomeini Street. In other words, these axes are the main axes in the spatial structure of Ardabil city and play the most role in shaping the spatial structure of Ardabil city. As expected, the heart of the city has the highest degree of inclusive connectivity. In general, based on the results of this study, it can be said that one of the most important factors influencing the changes in the fabric of Ardabil city over time is the changes in the degree of connectivity caused by the changes. It has been physical-spatial.In this regard, the most important suggestions are:The weak and strong points of the main morphology of each city should be redefined in the construction and urban development plans and identified with the help of the space layout method; The spatial structure of less developed neighborhoods should be investigated and analyzed before any intervention (renovation, reconstruction or improvement) by means of methods such as space layout; context-oriented urban planning and design should be taken into consideration and the spatial and non-spatial values of the area should be considered in urban plans; The role and impact of the main elements of the historical area of the city in the entire structure of the city should be considered and the inner structure of the neighborhoods and how it relates to the surrounding context should be understood and deduced to improve its structural problems; Equal distribution of uses and suitable neighborhoods to realize dynamism, activity and vitality in all the historical context of the city should be considered and investigated; In examining and analyzing the spatial structure of cities and problematic contexts, researches should be analyzed based on specific features in the spatial structure and organization related to the area.