عنوان مقاله [English]
Any concern for understanding changes in rapid urbanization, particularly those in a deteriorated urban area, requires the exhaustive investigation of the underlying factors for their evolution and subsequent development. In the recent development process of urban places, their central areas have gradually lost their values because the medium and high-income groups leave those places for the suburbs. Therefore, the centers of the cities faced with physical deterioration, economic and environmental problems and were occupied by the poor immigrants and low-income groups. In consequence of this migration and displacement, quality of life in these areas downgraded to so lowest possible that destructed the fabrics. Urban planners require detailed information about the functional, morphological and socio-economic structure of the built environment that are the first step to classify them in similar categories. Many of planners have emphasized on the importance of typology and classification as the first action and most important process of the intervention of the old fabrics. According to this, the focus of this study is to provide a scientific and systematic method to classify and typology deteriorated fabrics. Type as a concept refers to a kind, class, or category of people or group of objects that have certain characteristics in common, which are distinct from the other groups of objects. Hence it is possible to identify objects, events, and settings with specific characteristics.Typology is a descriptive and analytic tool that helps develop and refine concepts, tease out underlying concepts and create categories for classifying, measuring and sorting case studies so urban researchers often have tried to categorize and organize cities with typology frameworks. What it is interesting in this research is 1074 hectares of the city of Qom is covered with decline which allocated about 6.8 percent of the city’s legal limit its own and is occupied by over 220 thousand people. The principal aim of this study was to explore the main factors of urban deterioration, typology and classify old texture of Qom city based on effective homogeneous factors. So the present paper seeks the modeling that categorized homogeneously urban declined area in terms of physical, socio-demographic, economic and environmental characteristics
The present study is applied and is investigated by the library, and documentary studies. Statistical data include 1609 statistical deteriorated blocks in the city of Qom. The process of this study involves several steps. First, the effective indicators of deterioration were investigated; then, the measurement of the deteriorated blocks of the city was studied. These were done by using factor analysis model type R, in which research indicators were loaded into four factors: physical, socio-demographic, economic, and environmental factors. After specifying the main factors and measuring deterioration in each block in the city, the kernel density estimation method was used because of the typology of the old fabric of the city. The data analysis was made using inferential statistical methods using SPSS and ArcGIS10 software.
Result and discussion
Due to the complexity of the urban deterioration phenomenon, it is impossible to study urban deterioration in Qom city as a discrete and individual phenomenon so identification of main factors and typology of the deteriorated district of Qom need several steps. The first step is to identify the main factors and measure urban deterioration. Factor analysis as a powerful tool is responsible to develop solutions to reduce and analyze the factors. The results of this research showed that 20 indicators by using factor analysis were reduced to 6 factors which are the most effective indicators to identify old fabrics in the city of Qom. Accumulatively all the extracted factors explained 67.95 percent of urban decayed fabrics. Economic and social factors were known as the main factors in the deteriorated fabric of the city of Qom. The measurement of the deterioration of the city had the most relationship with economic indicators such as land price, occupational classification, income groups and housing facilities. Then, in association with the priorities of development and intervention in the old fabrics, the district is categorized into five different levels (or priorities) based on their surface deteriorated textures. the results obtained from a kernel density estimation of deteriorated locations showed that the highest concentration of urban deterioration are located mainly in the north and south of the deteriorated district of the city and had the most prone and highest probability of severity and extension of the deterioration, therefore, to intervene and renovate this district, these places have the highest priorities.
Urban deterioration and decline are created and aggravated by many factors and variables and are considered as one of the most severe environmental and socio-economic problems of recent times. These areas faced with physical deterioration, economic and environmental problems and were occupied mostly by the poor immigrants and low-income groups. Renovation and intervention in deteriorated areas are a complex and multidimensional process, and a unique phenomenon for each city. Adopting the same approaches and strategies to develop cities despite their heterogeneities and their differences in terms of physical, socio-demographic, economic and environmental conditions of cities result in unbalanced planning and encountering cities with unsustainable cycles of socio-economic and environmental imbalances ,and causing unprecedented challenges such as urban poverty, and creation of suburban and informal districts which have contributed to cultural conflicts, decline in quality of life and so on. Urban management has been undergone huge costs by the hasty and unplanned intervention. Therefore, to renovate the city, we need to typology and classify this area to grasp the homogeneous context and main factors. The facilities and resources of the organizations related to urban renewal and rehabilitation require at first identify the worn tissues and prepare a map of the zoning of worn-out tissues. The typology of the urban fabric, taking advantage of a rigorous and versatile cartographic tool. This study has empirically demonstrated that this phenomenon related to many factors. Identifying effective factors helps adopt better urban policies, so these findings can scientific basis for urban policy and planning in order to reduce deterioration and well intervene in urban texture.