تحلیل آسیب‌پذیری بافت‌های قدیمی شهر کاشان در برابر زلزله

نوع مقاله: مقاله علمی پژوهشی

نویسندگان

1 دانشیار گروه جغرافیا و برنامه‌ریزی شهری، دانشکده علوم جغرافیایی، دانشگاه خوارزمی، تهران، ایران.

2 کارشناسی ارشد برنامه‌ریزی شهری، موسسه آموزش عالی خاوران، مشهد، ایران.

3 کارشناسی ارشد برنامه‌ریزی شهری، دانشگاه آزاد اسلامی واحد یاسوج، یاسوج، ایران.

4 کارشناسی ارشد جغرافیا و برنامه‌ریزی شهری، دانشکده علوم جغرافیایی، دانشگاه خوارزمی، تهران، ایران.

چکیده

بافت‌های فرسوده شهری در کشورهای درحال‌توسعه، بنا به دلایلی مختلفی بیشتر از سایر بافت‌های شهری در معرض خطر زلزله قرار دارند؛ بنابراین شناخت صحیح ابعاد و اصول مدیریت بحران ناشی از زمین‌لرزه می‌تواند به‌عنوان اولین گام در فرآیند مدیریت بحران و به‌عنوان یکی از اساسی‌ترین دستورالعمل‌ها جهت اجرائی نمودن مدیریت بحران زمین‌لرزه محسوب می‌گردد. برای تحلیل آسیب‌پذیری لرزه‌ای بافت‌های فرسوده، بر نقش مؤثر شاخص‌های برنامه‌ریزی شهری در کنار شاخص‌های سازه‌ای، در برنامه‌های مقابله با زلزله تأکید می‌شود. هدف از این پژوهش شناسایی میزان آسیب‌پذیری اجزاء و عناصر شهری با استفاده از مدل‌ها و روش‌های موجود در کاهش آسیب‌پذیری در برابر زلزله می‌باشد. با استفاده از مدل Fuzzy AHP، سیستم اطلاعات مکانی و نرم‌افزار Expert choice، به بررسی آسیب‌پذیری بافت فرسوده شهر کاشان، از دیدگاه مدیریت بحران پرداخته‌شده است. نتایج پژوهش نشان داد که ازنظر آسیب‌پذیری 11 درصد بافت در آسیب‌پذیری خیلی کم، 7 درصد در آسیب‌پذیری کم، 15 درصد در آسیب‌پذیری متوسط، 22 درصد در آسیب‌پذیری بالا و 45 درصد در آسیب‌پذیری خیلی بالا قرار دارند. توزیع فضایی آسیب‌پذیری در مرکز بافت به دلیل عدم استفاده از مصالح مقاوم، کیفیت نامطلوب و قدمت زیاد ابنیه، بیشتر از سایر نقاط بافت می‌باشد. کمترین آسیب‌پذیری در جداره اصلی بافت بخصوص در قسمت جنوب شرقی واقع‌شده است. درنهایت یافته‌ها نشان داد که در بعد «کیفیت»، «به‌کارگیری اصل خطرپذیری مدیریت بحران» و در بعد «قدمت»، «شبکه معابر و دسترسی به فضای باز» و به‌کارگیری اصل «آینده‌نگری مدیریت بحران» می‌تواند به میزان بسیار زیادی آسیب‌پذیری بافت فرسوده را در برابر خطر زلزله کاهش داد داد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Analysis of the Vulnerability of Urban Decayed Textures of Kashan City against Earthquake

نویسندگان [English]

  • Ali Shamai 1
  • Atefeh Daneshvar Khorram 2
  • Ahmad Ravanbakhsh 3
  • Majid Afsar 4
1 Associate professor, Department of Geography and Urban Planning, Faculty of Geographical Sciences, University of Kharazmi, Tehran, Iran.
2 M.A of Urban Planning, Khavaran Institute of Higher Education, Mashhad, Iran.
3 M.A of Urban Planning, Islamic Azad University Yasuj , Yasuj, Iran.
4 M.A of Geography and Urban Planning, Faculty of Geographical Sciences, University of Kharazmi, Tehran, Iran.
چکیده [English]

Extended Abstract
Introduction

Due to the increasing occurrence of natural disasters in recent years around the world, especially earthquakes, and consequently the increase in losses and damages caused by earthquake in human societies, especially cities, the reduction of vulnerability against these events have particular importance. The old urban textures in developing countries, for various reasons, are at more risk of earthquake. Therefore, the understanding of earthquake crisis management principles in urban areas may be a first step in the crisis management and one of the most basic guidelines for the implementation of earthquake crisis management. Due to having numerous faults, seismicity background, and lots of old textures, Kashan is at relative risk of moderate seismicity. This necessitates taking measures in earthquake disaster management in Kashan.


Methodology

This was a descriptive - analytic study in terms of methodology. Given the nature of data, this was a non-experimental research. In the first step, the data were collected studying the library various texts and documents texts on earthquake and its damage in urban areas, particularly old textures. In the next step, the data were collected by field study and using local information and statistics and information of consulting engineers and related organizations. Finally, the data were transformed to maps. In the analysis, first all the data and values of parameters were extracted. Based on Analytical Hierarchy Process (AHP) and Expert choice, the relevant indices were weighted. Using GIS software, the zoning map of district vulnerability was provided with FUZZY logic. Finally, conclusions and recommendations were provided with respect to all discussed information.


Results and Discussion

The indicators such as the type of material, age of buildings, floors of the building, access to roads, and etc. are important in assessing the vulnerability of cities to earthquake. The synthesis using GIS and multi-criteria assessment AHP methods had an effective role in vulnerability assessment. Also, it made possible the comparing of various indicators and final vulnerability with regard to different indices. The techniques used in this study can be generalized to other cities in Iran. After reviewing the different perspectives and approaches in the field of crisis management and cities earthquake vulnerability, the systematic approach was selected as the theoretical framework of research. This approach is actually originating from crisis management perspective. According to the study purpose which is reduction of vulnerability and earthquake damages, the risk reduction which is mainly related to pre-crisis was selected as policy of this study. According to studies which were conducted on desired area, it was concluded that Mohtasham, Kashan district, with its numerous fault, was among Iran’s high-risk areas.
The binary comparison of indicators suggested that given its importance against earthquake, the building materials had the highest score. The experience of recent earthquakes has shown that the type of building materials used to construct is one of the important factors affecting vulnerability caused by the earthquake. In total, nine indices were used to assess vulnerability. The level of damage to buildings in this urban district was divided into five groups including very low, low, medium, high, and complete vulnerable zones.


Conclusion

The results showed that 10% of area had very low vulnerability, 19% had low vulnerability, 15% had medium vulnerability, 47% had high vulnerability, and 9 percent had very high vulnerability. The spatial distribution of vulnerability in area was associated with lack of using resistant materials, poor quality, and old buildings. The lowest vulnerability was in major part of texture, especially in the southeastern part of area. The crisis management includes 8 principles. Finally, the results showed that the use of crisis management principles, access to open space, and the use of forward-looking crisis management principles may greatly reduce vulnerability against earthquake risk in Mohtasham area.
Results and Discussion

The indicators such as the type of material, age of buildings, floors of the building, access to roads, and etc. are important in assessing the vulnerability of cities to earthquake. The synthesis using GIS and multi-criteria assessment AHP methods had an effective role in vulnerability assessment. Also, it made possible the comparing of various indicators and final vulnerability with regard to different indices. The techniques used in this study can be generalized to other cities in Iran. After reviewing the different perspectives and approaches in the field of crisis management and cities earthquake vulnerability, the systematic approach was selected as the theoretical framework of research. This approach is actually originating from crisis management perspective. According to the study purpose which is reduction of vulnerability and earthquake damages, the risk reduction which is mainly related to pre-crisis was selected as policy of this study. According to studies which were conducted on desired area, it was concluded that Mohtasham, Kashan district, with its numerous fault, was among Iran’s high-risk areas.
The binary comparison of indicators suggested that given its importance against earthquake, the building materials had the highest score. The experience of recent earthquakes has shown that the type of building materials used to construct is one of the important factors affecting vulnerability caused by the earthquake. In total, nine indices were used to assess vulnerability. The level of damage to buildings in this urban district was divided into five groups including very low, low, medium, high, and complete vulnerable zones.


Conclusion

The results showed that 10% of area had very low vulnerability, 19% had low vulnerability, 15% had medium vulnerability, 47% had high vulnerability, and 9 percent had very high vulnerability. The spatial distribution of vulnerability in area was associated with lack of using resistant materials, poor quality, and old buildings. The lowest vulnerability was in major part of texture, especially in the southeastern part of area. The crisis management includes 8 principles. Finally, the results showed that the use of crisis management principles, access to open space, and the use of forward-looking crisis management principles may greatly reduce vulnerability against earthquake risk in Mohtasham area.

کلیدواژه‌ها [English]

  • Seismic vulnerability
  • urban textures decayed
  • Crisis Management
  • Kashan
  • AHP- Fuzzy

مقالات آماده انتشار، پذیرفته شده
انتشار آنلاین از تاریخ 30 خرداد 1397
  • تاریخ دریافت: 25 شهریور 1393
  • تاریخ بازنگری: 29 خرداد 1397
  • تاریخ پذیرش: 30 خرداد 1397