تبیین مفهوم ریسک و سنجش میزان ریسک لرزه‌ای مناطق شهری (مطالعة موردی: نجف‌آباد)

نوع مقاله : مقاله علمی پژوهشی

نویسندگان

1 دانشجوی دکتری جغرافیا و برنامه‌ریزی شهری پژوهشگاه شاخص‌پژوه دانشگاه اصفهان

2 استاد گروه جغرافیا و برنامه‌ریزی شهری دانشگاه اصفهان

3 رئیس پژوهشگاه مهندسی بحران‌های طبیعی شاخص‌پژوه، استادیار گروه عمران-زلزله

چکیده

بر اساس نقشة پهنه‌بندی خطر زلزله در ایران، بخش زیادی از این کشور در محدودة خطر نسبتاً متوسط روبه‌بالا قرار دارد. از سوی دیگر، دوره‌های غیرلرزه‌ای بعضی گسل‌ها در سدة بیستم (حتی آرامشی هزارساله) نشان‌دهندة لرزه‌زا نبودن این گسل‌ها نیست. در این میان، قضاوت شهروندان از خطر باید بر این مبنا باشد که آن‌ها در منطقه‌ای زلزله‌خیز سکونت دارند. براین‌اساس ضروری است ارزیابی ریسک لرزه‌ای مناطق مختلف کشور با هدف کاهش خطرپذیری جوامع شهری در اولویت برنامه‌ریزی‌ها قرار بگیرد. در پژوهش کاربردی و توصیفی-تحلیلی حاضر، ضمن معرفی دیدگاه‌ها و مدل‌های مختلف مرتبط با مفهوم‌شناسی ریسک و آسیب‌پذیری، ریسک‌پذیری لرزه‌ای شهر نجف‌آباد بررسی شد. برای این منظور، از پارامترهای گوناگون کمی و کیفی براساس رویکرد تصمیم‌گیری چندمعیاره و روش تحلیل شبکه (ANP) و ارائة مدل کاربرد داشت. نتایج نشان می‌دهد حدود 60 درصد مساحت توسعه‌یافتة شهر - که دربرگیرندة ساختمان‌های خشتی و آجر و آهن است - ریسک‌پذیری متوسط روبه‌بالایی دارد. با تطبیق نقشة تراکم جمعیت بر این پهنه، حدود یک چهارم جمعیت شهر (در بعضی قسمت‌ها با تراکمی بین 70 تا 100 نفر در هکتار) خطرپذیری بالایی دارند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Explaining the Concept of Risk and Analysis of Seismic Risk of Urban Areas (Case Study: Najafabad City)

نویسندگان [English]

  • Sowgol Fazel 1
  • Masood Taghvaei 2
  • Amir Mahmoodzadeh 3
1 PhD Candidate in Geography and Urban Planning, Shakhespajouh Research Institute, Isfahan, Iran
2 Professor of Geography and Urban Planning, Department of Civil Engineering, Isfahan University, Iran
3 Assistant Professor of Urban Planning, Department of Civil Engineering, Shakhespajouh Natural Crisis Research Institute, Isfahan, Iran
چکیده [English]

Introduction 
Iran is one of the most vulnerable countries of the world to the earthquake. According to the seismic hazard map of Iran, almost the whole territory of the country is in relatively medium to high hazard area. Najaf Abad town is located in 30 km of Isfahan with the population more than 221000 people (in the year 2011) and is a middle town. It has the most important service center following Isfahan within the urban set of Isfahan. In terms of geology, Najaf Abad is located within Sanandaj-Sirjan zone regarded as one of the most active zones. Based on the conducted studies, the occurrence of earthquake over this zone is constantly possible. With respect to the seismo-tectonics map of Iran, this county is located within a zone with a relatively medium hazard and the event of historical earthquakes in 20th century. The basic trend of faults and dynamic structures in this zone indicate the relatively high rate of seismicity of this area. Regarding the importance of the issues related to the earthquake, the main objective of this research is to study and analyze the risk of Najaf Abad city exposed to the possible earthquake. Basically, meaningful weights have been dedicated to physical and social attributes for evaluating the seismic vulnerability to provide a local model for practical application of seismic risky analysis. 
Methodology
The data gathered in library surveys are including the maps, development plan and urban planning, aerial images, and statistical data related to population census in 2011. The procedure is based on a multiple decision-making approach. In order to analyze the data, Analytical Network Process (ANP) and Super Decision software have been used as maps and informational layers in ArcGIS environment. Hence, we have selected 5 criteria and 18 sub-criteria were considered to prepare the vulnerability map of the town to the seismic risk. The criteria selection is based on previous studies and the views of some experts in this regard. The earthquake risk of the study area have been analyzed using theoretical concepts and proposed model. 
Results and discussion
Studying tectonic and faults conditions of the zone
Contact of the mountains surrounding the city with an active fault can threaten the city. The super-faults of Qom-Zafreh, Zagros and Rokh are located surrounding this district. The activity of the earthquake will certainly affect this area (Nabavi, 1976). Moreover, according to the studies recently done about the seismic condition of Isfahan, a lot of important active faults, some with a higher than 100 km long, have been detected within a radius of 100 Km of the Isfahan city (Safaei, 2005).
Studying seismic condition of Najafabad area
According to Iranian historical and Iranian earthquakes catalogues, there were several historical earthquakes (with magnitude higher than 5) and 95 earthquakes higher than 2.5 in magnitude in 1962-2014.
Urban vulnerability analysis by ANP model
The vulnerability of the city against the earthquake have been assessed as an integration of the effective factors including environmental, anatomic, social etc. and the coping capacity of community (emergency and management indices) in  Najaf Abad city through 5 basic criteria and 18 sub-criteria. Therefore, the maps related to sub-criteria were initially prepared and converted into raster. Then, to weight the above indices, ANP model was used into Super Decision software environment. Finally, obtained weights have been applied to the relevant layers and the maps were overlapped as general vulnerability map of the city.  
Evaluation of the earthquake risk to urban areas
The proposed model used in this survey emphasizes that the risk is resulted from two factors of hazard and vulnerability. In this model, the risk is based on the linear relationship between these factors as Risk = Hazard × Vulnerability. Study of the tectonic conditions of the zone showed that there is always the possibly of earthquake event in this area. Entire the area is affected by a possible earthquake. Hence, with respect to the risk map of the town, nearly 33% of undeveloped area of the city is under the high risk. In addition, about 27% of this area has medium risk in the buildings with brick and iron materials and those without proper foundations, often more than 30 years old.
Conclusion
The results of different models have indicated that the risk is the combination of hazard and vulnerability. In this survey, analysis of the zone tectonic conditions showed that the threat of earthquake hazard is inevitable for this city. The results have revealed that about 60% of developed areas of the town were in a medium to high risk level. These areas were located in the central district of the town mainly constructed by masonry buildings. Finally, the combination of the population distribution map and the risk map has also indicated that more than 51000 people are in the high to very high risk zone. 

کلیدواژه‌ها [English]

  • risk
  • Vulnerability
  • Hazard
  • earthquake
  • Najafabad
  1. آمبرسز، نیکلاس و چارلز ملویل، 1370، زلزله‌های تاریخی ایران، ترجمۀ ابوالحسن رده، انتشارات دانشگاه تهران، تهران.
  2. بمانیان، محمدرضا و همکاران، 1391، کاهش خطرپذیری شهر از بلایای طبیعی (زلزله) از طریق برنامه‌ریزی کاربری زمین، مطالعۀ موردی: ناحیۀ 5 از منطقۀ 3 تهران، دوفصلنامۀ مدیریت بحران، دوره یک ، شمارۀ 2، صص 5-15.
  3. ثقفی، محمدجواد، 1383، آسیب‌شناسی ساختمان (ساختمان‌های آسیب‌دیده از زلزلۀ بم)، نشریۀ هنرهای زیبا، دوره 17، شمارۀ 17، صص 42-53.
  4. جمی، نسرین، 1385، بررسی خصوصیات زمین‌شناسی و مهندسی نهشته‌های کواترنری در شهر اصفهان، پایان‌نامۀ کارشناسی ارشد دانشکدۀ علوم دانشگاه اصفهان.
  5. درویش‌زاده، علی، 1392، زمین‌شناسی ایران، چاپ پنجم، انتشارات امیرکبیر، تهران.
  6. زارع، مهدی و همکاران، 1391، گزارش شناسایی مقدماتی زمین‌لرزه‌های دوگانۀ اهر و ورزقان (استان آذربایجان شرقی)، پژوهشگاه بین‌المللی زلزله‌شناسی و مهندسی زلزله، تهران.
  7. شاهپسندزاده، مجید و مهدی حیدری، 1382، بررسی مقدماتی لرزه‌خیزی، لرزۀ زمین‌ساخت و خطر زمین‌لرزه در پهنۀ استان اصفهان، ماهنامۀ فنی-تخصصی دانش نما، سال دوازدهم ، شمارۀ 107-109، انتشارات سازمان نظام‌مهندسی اصفهان، صص62-67.
  8. صفایی، همایون، 1384، طرح پژوهشی شناسایی و بررسی توان لرزه‌ای گسل‌های اطراف اصفهان، معاونت شهرسازی و معماری شهرداری اصفهان، اصفهان.
  9. علوی‌پناه، کاظم و محمدصدیق قربانی، 1386، نقش سنجش‌ازدور و بررسی‌های میدانی در تجزیه و تحلیل‌های مورفوتکتونیکی، مطالعۀ موردی: بم، فصلنامه پژوهش‌های جغرافیایی، سال 39 ، شمارۀ 60، صص 15-29.
  10. غفوری آشتیانی، محسن، 1392، راهنمای کاربردی انجام تحلیل خطر زلزله، دفتر امور فنی، تدوین معیارها و کاهش خطرپذیری ناشی از زلزله، معاونت برنامه‌ریزی و نظارت راهبردی رئیس‌جمهور.
  11. فاضل‌نیا، غریب، حکیم‌دوست، یاسر و یدالله بلیانی، 1393، راهنمای جامع مدل‌های کاربردی GIS، ج اول، چاپ سوم، انتشارات آزادپیما، تهران.
  12. کامل باسمنج، بتول، میرجعفری، بابک و سید علی علوی، 1391، ارزیابی آسیب‌پذیری لرزه‌ای در منطقۀ یک شهر تبریز با استفاده از مدل تحلیل چندمعیارۀ فضایی، فصلنامۀ مدرس (برنامه‌ریزی و آمایش فضا)، سال شانزدهم، شمارۀ 2، صص 121-140.
  13. محمدی، مصطفی، 1390، مدل‌سازی مؤلفه‌های ریسک‌پذیر مؤثر در ایمن‌سازی شهر کرج، رسالۀ دکتری، گروه جغرافیا و برنامه‌ریزی شهری، دانشگاه تهران، تهران.
  14. محمودزاده، امیر و سید مهدی هاشمی، 1390، دستورالعمل ارزیابی لرزه‌ای ساختمان‌ها براساس آیین‌نامۀ کانادا، انتشارات علم‌آفرین، اصفهان.
  15. مهندسان مشاور نقش‌جهان پارس، 1390، تجدیدنظر طرح توسعه و عمران شهر نجف‌آباد.
  16. میرزایی، حسین و اسماعیل فرزانگان، 1383، بم و زمین‌لرزه‌اش می‌آموزد(آشنایی با مهندسی زلزله و عملکرد لرزه ای ساختمانها) ، انتشاراتمرکز تحقیقات ساختمان و مسکن، چاپ اول ، تهران.
  17. نبوی، محمدحسن، 1355، دیباچه‌ای بر زمین‌شناسی ایران، سازمان زمین‌شناسی کشور، تهران.
  18. ویسه، یدالله، 1378، نگرشی بر مطالعات شهرسازی و برنامه‌ریزی شهری در مناطق زلزله‌خیز، چاپ اول، پژوهشگاه بین‌المللی زلزله‌شناسی و مهندسی زلزله، تهران.

19. Amberseys, N. N and Melville, C. P., 1982, A History of Persian Earthquake, Cambridge Earth Science Series. (In Persian)

20. Bemanian, M. R. et al., 2013, Reducing the Risk of Natural Disasters (Earthquake) Through Land Use Planning, Case Study: Region 5 of Tehran Municipality, Journal Crisis Management, Vol.1 , No. 2, PP. 5-15. (In Persian)

21. Saghafi,  M., 2005, Assessment of Buildings Vulnerability in Bam Earthquake, Journal Honarhaye Ziba , Vol.17 , No. 17, PP. 42-53. (In Persian)

22. Jami, N., 2006, Surveing of Quaternary Deposits Geological and Engineering Characteristics in Isfahan, M.A Thesis in Science Faculty, Isfahan University. (In Persian)

23. Darvishzadeh, A., 2013, Iran Geology, 5th Ed, Publication of Amirkabir, Tehran. (In Persian)

24. Zare, M.  et al., 2012, Reporting of Preliminary Identification Dual Earthquakes in Ahar and Varzaghan, International Institute of Earthquake Engineering Seismology,  Tehran. (In Persian)

  1. 25.  Shahpasandzadeh, M., and Heidari, M., 2003, A Preliminary Study on Seismic, Seismic Tectonics and the Risk of Earthquakes in the Area in Isfahan, Journal of Daneshnama Vol. 12 , No. 107-109, Publication of Isfahan Engineering Organization. (In Persian)

26. Safaii, H., 2006, Research Project for Identification and Evaluation of the Seismic Faults Around the Isfahan, Deputy Mayor of Urban Planning and Architecture of Isfahan, Isfahan. (In Persian)

27. Alavipanah, K., and Ghorbani, M., 2007, The Role of Remote Sensing and Field Studies in the Analysis Morphotectonic, J Gheoghraphic Researches, Vol. 39 , No. 60, PP. 15-29. (In Persian)

28. Ghafoory Ashtiani, M., 2013, Practical Guide Earthquake Risk Analysis, Deputy of President in Strategic Planning and Monitoring. (In Persian)

29. Fazelnia, GH., Hakimdoost, Y., and Beliani, Y., 2014, The Comprehensive Guide for GIS Functional Models, Third Edition, Azadpeyma Publication, Tehran. (In Persian)

30. Kamel Basmenj, B., Mirgafari, B., and Alavi, A., 2012, Evaluation of Seismic Vulnerability of Region1 of the City of Tabriz Using Spatial Multi-Criteria Analysis, Journal Modaress, Vol.16, No. 2, PP. 121-140. (In Persian)

31. Mohamadi, M., 2011, Modelling for Risk Parameter Affected on Karaj City Safety, Phd Thesis, Geographic and Urban Planning Branch, Tehran University, Tehran. (In Persian)

32. Mahmoodzadeh, M., and Hashemi, M., 2011, Seismic Evaluation of Buildings Based on Regulations of Canada, Elmafarin Publication, Isfahan. (In Persian)

33. Jahan Pars Consulting Engineers, 2012, Master Plan of Najafabad City. (In Persian)

34. Mirzaii, H., and Farzanegan, E., 2004, Bam's Earthquake and Teaches, Building and Housing Research Center. (In Persian)

35. Nabavi, M., 1977, The Geological History of Iran, Geological Organization of IRAN. (In Persian)

36. Viseh, Y., 2000, Review of Urban Studies and Planning in Earthquake-Prone Areas, International Institute of Earthquake Engineering Seismology, Tehran. (In Persian)

37. Baban, S. M., 2014, Enduring Geohazards in the Caribbean: Moving from the Reactive to the Proactive, Chapter 2, University of West Indies Press, Jamaica, 256 p, ISBN: 978-976-640-204-4.

38. Chen, C. W.  et al., 2012, A Novel Strategy to Determine the Insurance and Risk Control Plan for Natural Disaster Risk Management, Natural Hazards, Vol. 64, No. 2, PP. 1391-1403.

39. Crichton, D., 1999, The Risk Triangle, Natural Disaster Management, PP.102-103.

40. Dewan, A. M., 2013, Vulnerability and Risk Assessment, In Floods in a Megacity (PP. 139-177). Springer Netherlands.

41. EmDat, C.R.E.D., 2013, The OFDA/CRED International Disaster Database, Belgium, Université Catholique De Louvain.

42. Fathizahraei, M.  et al., 2015, Reducing Risks in Crisis Management bBy GIS Adoption, Natural Hazards, Vol. 76, No. 1, PP. 83-98.

43. Fedeski, M., and Gwilliam, J., 2007, Urban Sustainability in the Presence of Flood and Geological Hazards: The Development of a GIS-Based Vulnerability and Risk Assessment Methodology, Landscape and Urban Planning, Vol. 83, No. 1. PP. 50-61.

44. Garcia, C.  et al., 2014, The Relevance of Early-Warning Systems and Evacuations Plans for Risk Management, In Mountain Risks: From Prediction to Management and Governance (PP. 341-364). Springer Netherlands.

45. Hoseini, M., and Niazi, L., 2003, The Role of Urban Planning and Design in Lifeline- Related Seismic Risk Mitigation, Proceeding of the 6th Conference on Lifeline Earthquake Engineering, Longbeach, Canadian.

  1. 46.  Islam, M. N., Malak, M. A., 2013, Community-Based Disaster Risk and Vulnerability Models of a Coastal Municipality in Bangladesh, Natural Hazards, Vol. 69, No. 3, PP. 2083-2103.

47. Keller, E. A, and Pinter, N., 2002,  Active Tectonic: Earthquake Uplift and Landscape, Newjersy, Prentic Hall.

48. Lankao, P. R., and Qin, H., 2011, Conceptualizing Urban Vulnerability to Global Climate and Environmental Change, Current Opinion in Environmental Sustainability, Vol. 3, No. 3, PP. 142-149.

49. Masuya, A., 2014, Flood Vulnerability and Risk Assessment with Spatial Multi-Criteria Evaluation, In Dhaka Megacity (PP. 177-202), Springer Netherlands.

50. Mcclure, J. et al., 2015, When a Hazard Occurs Where It Is Not Expected: Risk Judgments About Different Regions After the Christchurch Earthquakes, Natural Hazards, Vol. 75, No. 1, PP. 635-652.

51. Menoni, S., 2006, Introducing a Transdisciplinary Approach in Studies Regarding Risk Assessment and Management in Educational Programs for Environmental Engineers and Planners, International Journal of Sustainability in Higher Education, Vol. 7, No. 3, PP. 309-321.

52. Raftery, J., 2003, Risk Analysis in Project Management, Routledge.

53. Rodríguez, J. T., Vitoriano, B., and Montero, J., 2012, A General Methodology for Data-Based Rule Building and Its Application to Natural Disaster Management, Computers and Operations Research, Vol. 39, No. 4, PP. 863-873.

54. Sarris, A.  et al., 2010, Earthquake Vulnerability and Seismic Risk Assessment of Urban Areas in High Seismic Regions: Application to Chania City, Crete Island, Greece, Natural Hazards, Vol. 54, No. 2, PP. 395-412.

55. Shafiee, A.  et al., 2011, Ground Motion Studies for Microzonation in Iran, Natural Hazards, Vol. 59, No. 1, PP. 481-505.

56. Shi, W., and Zeng, W., 2012, Analysis and Design on Environmental Risk Zoning Decision Support System Based on UML,Springer–Verlag Berlin Heidelberg, PP. 799-804.

57. Tsai, C. H., and Chen, C. W., 2010, An Earthquake Disaster Management Mechanism Based on Risk Assessment Information for the Tourism Industry-A Case Study from the Island of Taiwan, Tourism Management, Vol. 31, No. 4, PP. 470-481.

58. Wang, Y. et al., 2011, A GIS-Based Spatial Multi-Criteria Approach for Flood Risk Assessment in the Dongting Lake Region, Hunan, Central China, Water Resources Management, Vol. 25, No. 13, PP. 3465-3484.

59. Willis, I. et al., 2014, Applying Neighbourhood Classification Systems to Natural Hazards: A Case Study of Mt Vesuvius, Natural Hazards, Vol. 70, No. 1, PP. 1-22.

60. Zebardast, E., 2013, Constructing a Social Vulnerability Index to Earthquake Hazards Using a Hybrid Factor Analysis and Analytic Network Process (F’ANP) Model, Natural Hazards, Vol. 65, No. 3, PP. 1331-1359.

61. www.Iiees.Ac.Ir

62. www.Gsi.Ir

63. www.Ngdir.Ir