كاربرد مدل شاخص محور (PTVA) در ارزيابي آسيب پذيري مخاطرات مركب (حريق در پي زلزله) در منطقه شهري

Assessing Physical Vulnerability of Multi-Hazard (Fire Following Earthquake),using an Indicator-Based Model (PTVA) in Urban Area

مناطق شهري بسياري به وسيله مخاطرات مركب مورد تهديد قرار مي‌گيرند كه منجر به ايجاد آسيب‌هاي جدي به انسان‌ها ، ساختمان‌ها و زير ساخت‌ها مي‌گردد. اين مسأله متأثر از تحولات مرتبط مانند شهرنشيني، ساخت و سازها در مناطق با آسيب‌پذيري بالا مي‌باشد. مهمترين هدف در اين مطالعه، توسعه رويكردي شاخص محور مي‌باشد كه بستري را براي ارزيابي آسيب‌پذيري در خصوص مخاطرات مركب (حريق در پي زلزله) فراهم مي‌نمايد. مدل شاخص محور ارائه شده، بر اساس انتخاب مشخصات رتبه هايي مي‌باشد كه شاخص‌هاي آسيب‌پذيري كالبدي و انساني را در محدوده مورد مطالعه مطرح مي‌نمايد. كاربرد مدل PTVA، در محدوده اي از شهر شيراز مي‌باشد. تجزيه و تحليل اطلاعات جمع آوري شده بر اساس نوع و هدف مطالعه باتوجه به روش‌هاي آماري و مبتني بر مشخصات ارزيابي ريسك كمي با استفاده از نرم افزارهاي HAZUS & GIS و تجزيه و تحليل آسيب‌پذيري معيار محور (RVI) مي‌باشد، يافته‌ها در برآورد سطوح آسيب‌پذيري كالبدي و انساني (تلفات) نهايي حاكي از اين مي‌باشد كه 69 ساختمان با مساحتي برابر 47523.64 متر مربع از محدوده مورد مطالعه داراي سطح ريسك گسترده و كامل مي‌باشند.

Many built-up areas are threatened by multiple hazards which pose significant threats to humans, buildings and infrastructure. However, the analysis of the physical vulnerability towards multiple hazards is a field that still receives little attention, although vulnerability analysis and assessment can contribute significantly to risk reduction efforts. In this paper, an indicator-based vulnerability approach, the PTVA (Papathoma Tsunami Vulnerability Assessment), was further developed to be applicable in a multi-hazard context. The resulting multi-hazard version of the PTVA consists of four steps: the identification of the study area and relevant hazards as well as the acquisition of hazard information, the determination of vulnerability indicators and collection of data, the weighting of factors and vulnerability assessment, and finally, the consideration of hazard vulnerability. After the introduction of the newly developed methodology, a pilot application is carried out in a part of Shiraz municipality located in the Iran. In this case study the vulnerability of buildings and humans is assessed. The implementation of the methodology leads to reasonable results indicating the vulnerable buildings and supporting the priority setting of different end-users according to their objectives. The constraints of the presented methodology are: a) the fact that the method is not hazard-intensity specific, thus, vulnerability is measured in a rather qualitative and relative way, b) the high amount of data required for its performance, and c) Indicator-based vulnerability approaches are flexible and can be adjusted to the different hazards as well as to specific user needs. Introduction: Multi hazard pose a serious threat to human life. It can cause considerable damages. The evaluation of the expected losses due to multi hazard requires a risk assessment. Multi-hazard risk assessment allows the identification of the most endangered areas and suggests where further detailed studies have to be carried out. Aim: This study aims to give a new methodology for Multi-Hazard Risk Assessment that makes the comparability analysis of vulnerability easier for different hazards and accounts for possible triggering (domino) effects. Methodology: Methods used in this paper are based on theoretical approach and documentation. Two types of hazards will be assessed, namely earthquake and fire following earthquake. Statistical Analysis: Semi-quantitative and quantitative approach would assess risk rates at both regional and local levels. Results and discussion: In this study, representation of a new methodology for multi hazards risk assessment includes determination of a model with parameters, consideration of the indicator-based pattern of vulnerability assessment that selected all of the relevant indicators and presented new classification of indicators based on comparison to different hazards and possible triggering (domino) effects. This means that a potential multi-hazard indicator could be higher than the simple aggregation of single risk indicators calculation. Conclusion: The focus is on establishing a general overview of the emerging issues, and indicating how hazard relations can be considered in multi-hazard studies. The hazard relations are identified and studied by means of a new method and the overlay of hazard areas to determine overlaps in final multi hazards map.