توزيع فضايي تاب آوري در برابر سوانح در سطح محلات كلانشهر تهران

Spatial Distribution of Community Disaster Resilience in Tehran Metropolis

خسارات بسيار جاني و مالي ناشي از سوانح طبيعي در كلان‌ شهرها ضرورت ارزيابي و ارتقاي تاب‌ آوري پيش از وقوع حادثه را نشان‌ مي‌دهد. كلان‌ شهر تهران كه مستعد زمين‌لرزه است، نيز از اين امر مستثنا نيست. لذا در مقاله حاضر، مجموعه‌اي از شاخص‌هاي تاب‌ آوري از سه مدل BRIC، CRI و CDRI، شناسايي‌شده و جهت ارائه شاخص تركيبي چندبعدي تاب‌ آوري كلان‌شهر تهران مورداستفاده قرارگرفته است. بامطالعه 368 محله تهران و با استفاده از روش تحليل عاملي اكتشافي، ابعاد تاب‌آوري در پنج بعد اجتماعي، بعد زيرساختي، بعد عملكرد اقتصادي، بعد جامعه‌اي–روابط همسايگي و بعد جامعه‌اي-مشاركت- تعريف‌شده‌اند. توزيع فضايي تاب‌آوري و ابعاد آن در سطح كلان‌شهر تهران نشان مي‌دهد كه محلات غربي و جنوبي شهر تهران و برخي از محلات در شمال شرقي وضعيت نامطلوبي ازنظر تاب‌آوري دارند. درصورتي‌كه ميزان تاب‌آوري در محلات مركزي و شرقي به نسبت بيشتر است. در ميان ابعاد تاب‌آوري نيز بعد زيرساختي بيشترين تأثير منفي را بر محلات‌ با وضعيت نامطلوب تاب‌آوري داشته است.

Different models of disaster resilience have been conducted to evaluate or promote resilience of cities prone to disasters. By considering resilience as a set of adaptive capacities, pre-event capacities influence resilience. Therefor providing a methodology and a set of indicators to measure the present conditions influencing disaster resilience within communities is the focal argument in assessment of resilience to natural hazards. As the resilience has different dimensions, one of the quantitative approaches to measure city disaster resilience is to construct a composite index. The composite index, which encompasses a set of resilience indicators, can help in resilience quantitative evaluation, comparison between geographic units in terms of resilience, and elucidate resilience spatial distribution or assess resilience in a specific place in different periods of time. Tehran Metropolis, the capital of Iran, is located at the southern foot of Alborz Mountains, and surrounded by several fault lines. High vulnerability to disasters of Tehran Metropolis as well as the increasing population and the accumulation of resources in the capital highlight the importance of assessing the disaster resilience of this city in order to take appropriate measures to compensate for the shortcomings before the natural events occur. Based on the context represented here, the main objective of this study is to construct a composite indicator for evaluating inherent community disaster resilience for Tehran metropolis. In this regard, a set of resilient indicators extracted from three evaluation models -Baseline Resilience Indicators for Communities )BRIC(, Community Resilience Index )CRI( and Community Disaster Resilience Index )CDRI( -were used to evaluate and construct a resilient composite index for Tehran metropolis. Taking into consideration indicators’ feasibility, operation ability as well as data-accessibility, 34 of the 143 identified indicators from the three models were selected at the neighborhood level )for the 368 neighborhoods of the City(. By using exploratory factor analysis, the inherent resilience dimensions are shown in five social, infrastructure, economic performance, community-neighborhood relations and community-participatory domains. The Kaiser–Meyer–Olkin )KMO( measure was 0.785, indicating that the correlation between the data is suitable for factor analysis and the cumulative variance of 5 factors explain 71.687 percent of the data variance. The spatial distribution of composite disaster resilience and its dimensions in Tehran metropolis indicate that the western and southwestern neighborhoods of the city have the least inherent resilience. The northern and central neighborhoods are in a better position than the southern neighborhoods in terms of resilience. Among the resilience dimensions, the infrastructure dimension has had the most negative impact on the neighborhoods with an adverse resilience situation. To conclude, the quantitative disaster resilience evaluation provides a clear picture of the status quo. Therefore, by assessing resilience in different geographic units, it is possible to compare and identify differences between areas, reduce shortcomings, and take advantage of opportunities. Besides, by measuring the resilience in different periods of time, one can understand any increase or decrease in resilience of a place and improve this quality before the events, especially in cities with high population density and prone to earthquakes like Tehran.