كاربرد روش تحليل عاملي در شناسايي بافت هاي فرسوده شهري

An Application of Factor Analysis Method in Identification of Decayed Urban Fabrics

موضوع نارسايي شاخص هاي سه گانه مطرح شده توسط شورايعالي شهرسازي و معماري ايران در راستاي شناسايي بافت هاي فرسوده شهري، همواره مورد انتقاد محافل مختلف قرار گرفته است. بر اين اساس، مقاله حاضر بر آن است تا به بازخواني شناسايي بافت هاي فرسوده شهري از طريق ارايه مدلي مناسب، و كاربست آن در بلوك هاي شهري محله هدف مطالعه پرداخته و عوامل و متغيرهاي اصلي فرسودگي شهري را كشف نمايد. روش تحقيق در اين مقاله تلفيقي از روش هاي فراتحليل و استفاده از متون معتبر جهاني در ارتباط با شاخص هاي فرسودگي از يك سو و روش تحليل داده هاي ثانويه مربوط به بلوك هاي شهري در محيط نرم افزارهاي تحليل آماري و سيستم هاي اطلاعات جغرافيايي از سوي ديگر است. يافته هاي اين مطالعه نشان مي دهد كه به ترتيب، عوامل اصلي شناسايي بافت هاي فرسوده در محله مورد مطالعه را، آسيب پذيري سازه اي، فرسودگي اقتصادي محروميت و فقر شهري تشكيل مي دهند كه در اين ميان دو عامل اول، حدود 50 درصد فرسودگي و سه عامل در كنار هم حدود 70 درصد فرسودگي شهري را تبيين مي كنند. همچنين تبيين ارتباط بين شاخص‌هاي معرفي شده در اين مطالعه با شاخص هاي سه گانه شورايعالي شهرسازي و معماري ايران نيز نشان داد كه شاخص هاي قيمت زمين، نرخ نوسازي، تراكم جمعيتي و خانوار در واحد مسكوني به ترتيب، ارتباط بيشتري را با شاخص هاي مربوطه دارند.

In recent years, the old urban fabrics identification has become a challenging issue in urban planning society in Iran. The insufficiency of triple indices which had been introduced by the High Council on Urban Planning and Architecture has been criticized by experts several times. In this paper we reconsider the existing urban fabrics identification method and introduce a suitable model and apply it in the urban blocks of an urban neighborhood, Karim Abad in Tehran, thus finalizing the principal factors and variables in identification of the urban decayed fabrics. Research method in this paper is a combination of meta-analysis and using reliable literatures about decayed urban fabrics indicators on the one hand and a data analysis method of secondary data of urban blocks from statistics analysis and GIS (Geographic information system) software on the other hand. Consequently, to reach the specific aims of the study, first, general decayed urban fabrics indicators were extracted from the related literature. Then, by combining some of these indcators and considering the specific conditions of the study area and also cheking for the applicability of adopting factor analysis method, nine urban decayed fabrics indicators were used in twenty four blocks of study area. The results of the present study show that the main factors of urban decayed fabrics identification in the study area are respectively, structural vulnerability, economic deterioration, social exclusion and urban poverty. Among these factors, the first and the second ones explain approximately 50 percent of urban decayed fabrics, and commulatively all the three extracted factors explain about 70 percent of urban decayed fabrics. Moreover, the explanation of the relationship between factors introduced in this study and those which had been introduced by the High Council on Urban Planning and Architecture, demonstrates that land cost, renewal rate, and population density are the indicators which respectively have the most connection with the previously introduced indices for identification of the decayed urban fabrics.Based on the studies of Lee and Bourne, which was mentioned in the theoretical framework of this study, application of new economic and social indicators in the process of decayed urban fabric identification is deemed necessary. Therefore, according to expert’s emphases and due to serious criticisms of the indicators used for the identification of decayed urban fabrics in Iran, in this paper, a new approach for identification of decayed urban fabrics with the application of social and economic indicators in the sample community is developed. Our findings show that the applied 9 soci-economic as well as physical indicators in 24 urban blocks of the case study, show that besides the criteria’s adopted by the High Council on Urban Planning and Architecture, the most important factors for identification of decayed urban fabrics are respectively, structural vulnerability, economic deterioration, social exclusion and urban poverty. Moreover, the explanation of the relation between factors introduced in this study and those which had been introduced by the High Council on Urban Planning and Architecture show that land cost, renewal rate, and population density, are the indicators which respectively have the most connection with the previously introduced indicators.