تحلیل عوامل موثّر بر پژمردگی شهری در ناحیه 3، منطقه 12، شهر تهران

با رشد شتابان شهرنشینی و گسترش فیزیکی شهرها، پدیدۀ پژمردگی شهری، بافت مرکزی بسیاری از شهرهای بزرگ جهان توسعه یافته و درحال توسعه را دربر گرفته است. پژمردگی شهری، تنزّل عملکردی و کالبدی بافت مسکونی و درپی آن، فضای اجتماعی شهر است. هسته مرکزی شهر تهران که در گذشته ای نه چندان دور، از مراکز مهم و پویای این شهر محسوب می شد، اکنون نشانه های پژمردگی شهری را در خود آشکار ساخته است. براساس این، هدف اصلی پژوهش حاضر، شناسایی و تحلیل عوامل موثّر بر پژمردگی شهری در ناحیه 3، منطقه 12، شهر تهران است. داده‌های مورد نیاز با استفاده از پرسش نامه محقّق‌ساخته، به طور تصادفی ساده از دویست خانوار ساکن در محدوده مورد مطالعه گردآوری شده است. از آزمون آماری تی تک نمونه ای برای مقایسه میانگین ها، تحلیل عاملی برای کاهش تعداد متغیّرهای مستقل و شناسایی ابعاد پژمردگی شهری و درنهایت از تحلیل رگرسیون برای شناسایی عوامل موثّر بر شکل گیری پدیده پژمردگی شهری در ناحیه 3، منطقه 12 شهر تهران در محیط نرم افزار آماری اِس.پی.اِس.اِس. استفاده شد. یافته های پژوهش نشان می دهد که براساس ادراک ذهنی ساکنان محلّی و نتایج حاصل از آزمون آماری تی تک نمونه ای، ناحیه 3، منطقه 12 شهر تهران دچار وضعیّت پژمردگی شهری شده است. نتایج تحلیل عاملی بیانگر آن است که پژمردگی شهری، پدیده ای چندبُعدی و پیچیده است. درمیان ابعاد گوناگون پدیدۀ پژمردگی، چهار عامل ویژگی های اجتماعی محلّه، کیفیّت فیزیکی محلّه، کیفیّت مسکن و سرمایه اجتماعی، مهم ترین پیش‌بینی‌کننده‌های پژمردگی شهری در محدوده مورد مطالعه هستند. این چهار عامل، بیش از 67% واریانس پژمردگی شهری را در محدوده مورد بررسی تبیین می کنند.

The Analysis of the Effective Factors on Urban Blight in District 3, Region 12, Tehran City

IntroductionThe complex intraurban movements are considered as the manifest characteristics of the cities on the growth; they may lead to socioeconomic and physical inequalities in urban areas. In this process, the central areas of the cities are affected more than other ones. Since the old city or the central part of today’s cities has not been able to upgrade its previous efficient, dynamic, and satisfactory structure to today’s conditions, it has experienced a reduction in environmental quality and, in the broad sense, decay, deterioration, and blight. As a result, many inhabitants of the initial core of the city would rather move toward new locations in order to get a better life quality. After the movements of old inhabitants, their houses are mostly occupied by lowincome and jobseeking immigrants. The undesirable multidimensional changes in social and economic structures and their echoes in physical and environmental structures make the social, economic, and physical conditions dominate the urban centers which finally lead to a reduction in the environmental quality and their blight.In accordance with population growth and physical extension, the central part of Tehran has experienced many changes including the movements of original inhabitants and resettled immigrants, changes in the combination and variety of urban land use making them the backup land uses of some of the original ones, coincidence of functional fatigue and physical fatigue, the increase of crime and social harms, and the decrease of the level of public services required by inhabitants. Accordingly, the central part of Tehran has manifested some characteristics and signs of blighted urban areas and, as a result, this has made this part of the city suspicious to a zone with the characteristics of urban blight. Thus, the current study with emphasis on the mental dimension attempts to identify and analyze the factors affecting the formation of urban blight phenomenon in District 3, Region 12 of Tehran City.Materials and MethodsThis study is mostly based on the initial data resulted from surveying the households using a researchermade questionnaire; however, the tools of the interview, observation, and the results obtained from the public censuses of population and housing are also used to achieve the required data and information. The statistical society of the study is all the households in District 3, Region 12 of Tehran City (10710 households). The sample size was determined as 200 households according to Cochran formula, although there were challenges like the very low willingness of the residents to participate in research, the various social and security challenges the researchers face in case study area, and the time and financial limitations of the research. The sampling method in the case study area was a simple random method—from the parents or one of the family members older than 16 years old. The single sample Ttest was applied to summarize the survey results and compare the averages respectively. Moreover, a factor analysis was employed to reduce the number of independent variables and identify the urban blight dimensions. At the end, the regression analysis was used to identify the factors affecting the formation of urban blight phenomenon in District 3, Region 12 of Tehran City in SPSS software environment.Results and DiscussionAccording to the opinions of respondents and the results of Ttest, it can be said with a confidence level of 99% that District 3, Region 12 of Tehran has an undesirable status in most of the studied indices including the existence of vacant houses, ruins, and abandoned lands, privacy and quietness of neighborhood, traffic condition in neighborhood, existence of leisure, recreational, and sports spaces, vitality and dynamism of neighborhood, hope to improve the neighborhood conditions in the future, willingness to reside in neighborhood, and general assessment of inhabitants from neighborhood quality. In addition, by aggregating the indices and creating the final urban blight index, the singlesample Ttest was used again for this index. From the obtained results, it can be said—with a confidence level of 95%that form the local residents’ point of view, their residence place in District 3, region 12 of Tehran has an undesirable status.After validating the blight status according to the mental perceptions of local residents, the current research considers the identification of the factors affecting the formation of urban blight phenomenon in District 3, Region 12 of Tehran. The number of extracted factors is 6 factors based on the eigenvalue criterion and scree plot. These 6 factors express 69.53% of total variance in data. After determining the dimensions of urban blight, the regression analysis was used by a stepbystep method to identify the factors affecting urban blight in District 3, Region 12, Tehran. The dependent variable in the regression analysis is the final urban blight index, while the independent variables are the 6 factors extracted from the factor analysis. The results obtained from the stepbystep regression analysis show that four factors out of 6 factors extracted from the factor analysis totally express 67.5% of the urban blight variance in the case study area. Four factors of social characteristics (in the first step), neighborhood physical quality (in the second step), housing quality (in the third step), and social capital (in the fourth step) enter the model respectively which totally express 67% of urban blight variance.Conclusion The research results show that urban blight is a complex and multidimensional phenomenon. Among the various dimensions of blight phenomenon, four factors of social characteristics of the neighborhood, physical quality of the neighborhood, housing quality, and social capital are the most important predictors of urban blight in the case study area. The results of the research can be considered by urban planners, policymakers, and managers as a guide to control urban blight phenomenon and improve the life quality of the residents in District 3, Region 12 of Tehran.