ارزيابي تاب آوري اجتماعي و اقتصادي منطقه 3 شهرداري شيراز در برابر زلزله با استفاده از شبكه هاي عصبي مصنوعي

Evaluating the Components of Social and Economic Resilience against earthquake in the 3rd Municipal District of Shiraz City

امروزه جوامع محلي در تلاش براي دست يابي به شرايطي هستند كه در صورت وقوع بحران، بازگشت سريع آن ها را به وضعيت پيش از بحران فراهم سازد. بنابراين ديدگاه غالب از تمركز بر روي كاهش آسيب پذيري به افزايش تاب آوري در مقابل سوانح تغيير كرده است. تاب آوري به ظرفيت سيستم هاي اكولوژيكي براي جذب اختلالات و حفظ ساختارهاي لازم سيستم اطلاق مي-شود. شهر شيراز در منطقه لرزه خيز زاگرس قرار گرفته كه داراي استعداد لرزه خيزي بالايي مي باشد. با توجه به اهميت كاربري-هاي موجود در منطقه 3 شهرداري شيراز، هدف اين پژوهش سنجش ميزان تاب آوري اجتماعي- اقتصادي در برابر زلزله در اين منطقه است. پژوهش حاضر از نظر هدف، كاربردي و از نظر شيوه انجام، توصيفي- تحليلي است. بدين صورت كه با استفاده از مطالعات كتابخانه اي همه معيارهاي مورد ارزيابي مناسب اين منطقه استخراج گرديد. سپس جهت بررسي تجزيه و تحليل چند متغيره بين متغيرها و همچنين برآورد متوسط متغير وابسته(تاب آوري اجتماعي- اقتصادي) براساس مقادير متغيرهاي مستقل(متغيرهاي زمينه اي اجتماعي- اقتصادي) مدل رگرسيون خطي چندگانه به كار رفته است. نهايتا براي تعيين "سهم مولفه-هاي تاب آوري اجتماعي و اقتصادي در تبيين ميزان تاب آوري خانوارهاي اين منطقه " از مدل شبكه عصبي مصنوعي، استفاده شده است. با توجه به نتيجه ي رگرسيون خطي با كاهش ميزان درآمد صرف ضروريات ميزان تاب آوري افزايش مي يابد. از ميان شاخص هاي مورد مطالعه مولفه سرمايه اجتماعي و مهارت مهم ترين و مولفه هاي ميزان و شدت خسارت و توانايي بازگشت به شرايط شغلي و مالي مناسب كم اهميت ترين متغير در پيشبيني تاب آوري كل برخوردارند. بنابراين مولفه هاي اجتماعي در اين مطالعه تاثير بيش تري در ميزان تاب آوري دارند.

Introduction Nowadays, considering the unexampled urban population growth, natural disasters prevention and control especially earthquake and increasing urban resilience are among main challenges in urban management. Urban resilience stands for the ability of attracting and reorganizing the changes resulted from disorders, stabilizing the city and building capacity. The concept of resilience has been translated as the ability to recovery, quick improvement, change, feasibility and also flexible property. There are many discussions about the origin of resilience world. Some is related to biological area and others belong to physics. Community resilience should encompass economic, organizational, social and ecologic aspects of the society. Social resilience is the adaptive and learning capacity of individuals, groups and institutions to self- organise in a way that maintains system function in the face of change. In economic terms, resilience refers to inherent response and compatibility of people and society against hazard. Iran, due to its climactic and geological characteristics especially its location over Alps-Himalaya earthquake belt, is one of the most vulnerable countries of the world. Methodology Shiraz is in serious situation as a result of some factors. These factors are its location in a zone of high and very high seismic risk, failure to comply with safety rules like building in the privacy faults and the areas prone to geological instabilities, design and construction of inappropriate buildings and critical facilities with possible seismic intensity, no planning and required operational capabilities for disaster management for dealing with the consequences of an accident as well as the existence of multiple aging and vulnerable textures. Considering the importance of existing land uses in the 3rd municipal district of Shiraz city, the aim of this study was an evaluation of social and economic resilience in this district. This applied research is using descriptive and analytical methods. The indicators of social and economic resilience were identified from the literature. Social resilience factors include awareness, skill, attitude and social capital. Economic resilience factors include damage severity, recovery capacity and employment recovery. The data collection tool was a researcher-made questionnaire that included questions about socioeconomic characteristics of households and questions assessing dimensions and components of resilience. The estimated sample size using Cochran’s sample size formula was 383. Statistical inferences were made based on different test including multiple linear regression and multilayer perceptron artificial neural network. Result and Discussion This research provides a comparison of social and economical resilience to earthquake in the 3rd Municipal District of Shiraz City, based on these components: Mean score of social resilience was 40. Social capital is an important indicator of social resilience level of the communities. Mean score of economic resilience was 16.1. Employment recovery is an important marker of economic resilience to assess the extent and severity of damage to properties. It is worth mentioning that the coefficient of multiple determination or R-squared was 0.22 and 0.19 in regression models. Consequently, 22% of variance in total resilience and 19% of variance in total resilience are explained by social and economic variables. The predictive accuracy of the models was evaluated using mean squared error (MSE) and root mean squared error (RMSE) loss functions. In this study a network with 7 input layers and 6 hidden layers performed. Conclusion The examination of the effect of underlying factors on the total amount of resilience, the results of the multiple linear regression model showed that with increased staying time in the area of residence the level of the economic resilience of households decreases. Furthermore, it indicated that a decrease in share of income spent on necessities could result in an increase in social and economic resilience of the households under study. Neural network analysis revealed that social capital and employment recovery are the most and least effective factors. In the population under study, social component, was the most important determinant of resilience. This means that although elements such as the strength of buildings, economic status, earthquake- training and advertisement of the government are apparently effective in resilience, variables such as earthquake awareness, skills, social capital are more critical and play a key role in resilience level of households in the 3rd Municipal District of Shiraz City. Also, the framework provided in this research can be applied to other neighborhoods for a measurement and analysis of the social and economical resilience level.