سنجش ميزان آسيب‌پذيري سكونتگاه‌‌هاي غيررسمي در برابر خطر وقوع زمين‌لرزه با استفاده ازGIS مورد پژوهش: محله زير نهر‌تراب شهر پارس‌آباد

Measuring the Vulnerability of Informal Settlements during the Earthquake with the use of GIS. Case Study: The Zire Nahre Torab Neighborhood, City of Parsabad

اغلب شهرهاي كشورهاي در حال توسعه با مسئله سكونتگاه‌هاي غيررسمي مواجهند. شكل‌گيري و رشد اين سكونتگاه‌ها به دلايلي از جمله ساخت‌ و سازهاي شتابان و خارج از عرف ساختماني، از مسائل تهديد كننده براي اجتماعات ساكن در آنها محسوب مي‌شود. از آنجايي كه خطر زمين‌لرزه در اغلب مناطق ايران، سكونتگاه‌هاي شهري و از جمله سكونتگاه‌هاي غيررسمي را تهديد مي‌كند، بررسي، سنجش و تحليل ميزان آسيب‌پذيري اين سكونتگاه‌ها در مقابل خطر وقوع زمين‌لرزه‌هاي احتمالي براي بكارگيري اصول مديريت بحران در مقياس محله‌اي ضروري است. هدف اصلي اين پژوهش، ارزيابي ميزان آسيب‌پذيري محله زير نهر تراب پارس‌آباد در برابر خطر وقوع زمين‌لرزه احتمالي است. اين پژوهش از نوع اسنادي و ميداني است. بعد از مطالعات اسنادي و تدوين مباني نظري، داده‌هاي خام به ‌صورت ميداني و از نهادهاي متولي گردآوري شده‌اند. سپس براي تعيين وزن معيارها، از روش فرآيند تحليل شبكه‌اي (ANP) استفاده شده است. در ادامه از مدل‌هاي همپوشاني در سامانه اطلاعات جغرافيايي (GIS) از جمله شاخص همپوشاني وزين (WOI) براي تلفيق زيرمعيارها و تعيين ميزان آسيب‌پذيري ساختمان‌ها، استفاده شده است. يافته‌هاي اين پژوهش نشان مي دهند كه؛ در هنگام وقوع زلزله احتمالي، ميزان آسيب‌پذيري حدود 80 درصد از واحدهاي ساختماني محله زير نهر تراب، زياد و بسيار زياد است. از اين‌رو،، براي پيشگيري از وقوع بحران، پيشنهاداتي بر مبناي مؤلفه‌هاي پژوهش ارائه شده‌اند.

Most of the large cities in developing countries have faced with the problem of informal settlements. The formation and growth of these settlements for reasons such as rapid and outside the customs building construction are the threatening issue for their communities. Informal settlements are areas that often shaped and expanded in major and middle cities of the Iran’s cities including the city of Parsabad. During the last decades، the rapid growth of urbanization and the lack of appropriate planning for low-income families housing leads to the formation of the urban informal settlements in most cities of the Iran. In most cases، these settlements have a structural and demographic dense texture. The structural texture of these settlements is often fine aggregate، impermeable، and unstable. In times of crisis، the possibilities of human and material losses to them are high. Environmental hazards such as earthquakes are a serious threat to these settlements. However، these hazards in most developing countries، due to the unavailability and lack of preventive actions، end to the crisis. We cannot prevent earthquakes. But we can reduce the losses and damages caused by the earthquakes. Remove of the disaster is impossible، but it is possible to reduce the damage caused by the disaster. One of the most important ways to reduce the risk of earthquakes is preparation to deal with earthquakes. Preparation means having previous programs and plans. Iran is one of the countries where earthquakes always happen. Because Iran located in the world's earthquake belt، each year on average about 1،000 earthquakes happening in Iran. Ardebil and Pars-Abad city، located in an area that the possibility of earthquakes shakings in these areas، is more. The Zire Nahre Torab Neighborhood is one of the Parsabad city’s informal settlements that located in the northwest of the city. Regarding the possibility of an earthquake in the city of Pars Abad، identification and assessment the vulnerability of the neighborhood during an earthquake، is essential. Therefore، identifying and assessing the vulnerability، especially in the poor neighborhoods to offer strategies for dealing with the injuries، is essential. The aim of this study is assessing vulnerability of the informal settlements during an earthquake by using spatial data and GIS. This study، have been prepared in fifth main parts including: introduction and background، methodology and presentation of case study، theoretical framework، analysis and conclusions. This research in terms of the nature is practical and is descriptive and in terms of the method is analytical. Three methods including library، documentary and survey have been used for data collection. In the first phase، data and base maps were extracted from documents and reports of projects such as city comprehensive and detailed plans. Also، in this phase of the study data were updated. In the second phase، the problem، questions and research objectives were defined. In the third phase، the 3 criteria and 12 sub-criteria based on research literature and according to available data were selected. In the fourth phase، after preparation of databases related to each of the criteria in GIS، input layers were prepared for each of them. In the fifth step، the method of network analysis process (ANP) was used to determine the significance of criteria. In the sixth phase، the weighted overlay index (WOI) was used for combining output layers. The results of this study show that more than 80% of neighborhood buildings are vulnerable against the risk of a possible earthquake. Also، research findings suggest that physical characteristics such as building structure، quality and age of the buildings will have the greatest role in determining the neighborhood buildings vulnerability level. Doing activities such as resisting buildings، improving roads، locating facilities in appropriate places، training and informing citizens to prevent a crisis caused by the possible earthquakes، is essential. Other recommendations are listed in below: 1.Identifying vulnerable buildings 2.The use of GIS in the management of settlements 3.Preparations cities، to deal with urban hazards 4.Empowering citizens to deal with environmental hazards 5.Action to reduce earthquake risk 6.Civil engineering Renovation of buildings 7.New practices in the urban construction 8.Equip cities with facilities and relief supplies. 9.The use of specialists in urban planning. 10.Conducting workshops on urban resilience.