ارزيابي توان اكولوژيكي توسعه شهري با استفاده از روش ANP و منطق فازي در GIS (مطالعه موردي: شهر جديد بهارستان (اصفهان))

Assessment of Ecological Competence of Urbun Expansion through ANP and Fuzzy Logic Methods in GIS (Case Study: Baharestan New Town, Esfahan)

آنچه در فرآيند ارزيابي توان اكولوژيك مد نظر قرار مي گيرد، تاثير متقابل منابع اكولوژيك پايدار و ناپايدار است كه به صورت ويژگي هاي هر اكوسيستم خرد اثرات متقابل بر يكديگر و محيط زيست مي‌گذارند؛ لذا ذكر اين نكته ضروري است كه بهره مندي از طبيعت به گونه‌اي كه كمترين زيان به محيط وارد شود و در كنار آن بهترين بهره‌وري براي انسان به دست آيد، مدنظر است. به همين منظور با توجه به هدف اصلي در اين تحقيق، شهر جديد بهارستان واقع در استان اصفهان، جهت ارزيابي توان اكولوژيك به منظور توسعه شهري بر اساس اصول آمايش سرزمين، با استفاده از سامانه اطلاعات جغرافيايي(GIS) مورد مطالعه قرار گرفت. بر اين اساس ابتدا مطالعات پايه انجام و نقشه‌هاي موضوعي منطقه تهيه و سپس رقومي سازي شد‌. آنگاه مدل رقومي ارتفاعي (DEM) با استفاده از نقشه توپوگرافي در محيط Arc gis 10.2 توليد شد. سپس با همپوشاني و تلفيق نقشه‌هاي ارتفاع، شيب، جهت، انواع خاك، بافت خاك، عمق خاك، پوشش گياهي، زمين شناسي، كاربري اراضي، اقليم و فاصله از گسل با روش‌هاي ANP و منطق فازي در محيط Arc gis 10.2، نقشه توان اكولوژيكي توسعه شهري تهيه شد. نتايج كلي بيانگر آن است كه كل محدوده‌ي توسعه با مساحتي حدود 264/068 هكتار در قسمت جنوب شرقي و شمالي بهارستان قرار دارد كه با تدقيق اين محدوده و در نظر نگرفتن محدوده‌هايي كه در ارتباط با تأمين اراضي مناسب توسعه كارآيي ندارند، محدوده‌اي حدود 2800/717 هكتار جهت برنامه‌ريزي توسعه‌ي آتي شهر بهارستان در نظر گرفته ‌شده است

Introduction The reciprocal effect of sustainable and unsustainable ecological resources is considered in the course of assessment of ecological capacity. These resources have reciprocal effects to each other and environment as specifications of each micro ecosystem. So, it is obligatory to utilize nature as it less harms environment and at the same time its benefits human more. Therefore, an appropriate urban development will also be realized when applied to the land in proportion to its potentials and capabilities. Therefore, it is very important to identify the potentials and capabilities of the land before deployment on it and the loading of urban utilities and activities; In this regard, the main issue in assessing the ecological capability of the new city of Baharestan is the application of environmental criteria in its urban development to achieve sustainable urban development and a suitable model for the future development of the new city of Baharestan in Isfahan. The main objective of this study is to determine the suitable location for urban development, the new city of Baharestan, with a fuzzy method that will have the least harmful effects now and in the future. Methodology Therefore, the main objective of this research, to assess the ecological capacity for surface expansion of town based on principles of reclamation of land, Baharestan new town in Esfahan Province was studied through geographical information system (GIS). At first, the basic studies were done and the theme maps of the area were prepared and then numerated. Digital Elevation Model (DEM) was produced in Arc gis 10.2 using topographic map. Then, the ecological resources Urban development map were produced by overlying the maps of elevation, slope, aspect, soil types, soil texture, soil depth, vegetation cover, geology, landuse, climate and distance to fault with ANP and Fuzzy logic methods in Arcgis 10.2. Results and discussion When the city needs to expand its population in order to locate its extra population, firstly the expansion of the city and the use of the Baier land are considered to be the most appropriate pattern of expansion, especially for cities with no high relative density; Because this kind of expansion is always done with increasing density. One of the main objectives of the present study is to determine the proper pattern for the future development of the new Baharestan city; Therefore weighing is done taking into account the abovementioned criteria and the following: - The appropriate areas of development of the city are in terms of gradient between (15-3) percent. -The proper areas of development of the city from a height dimension below 1800 meters above sea level. Suitable zones for developing the city are not at the core of the main faults. - The appropriate areas of development of the city are not located on agricultural lands. Of course, due to the spatial disparities and the environmental weaknesses and limitations of the area, somewhat interfered with the factors based on studies of weighting factors. The results of the action of overlapping layers and weighing the factors mentioned above indicate that with the observance of the above criteria, the appropriate areas of urban development will be limited. Such an outcome reflects the fact that within the scope of the study one can not consider a particular direction or area for the development of the city, but the future development of the city is possible by observing the parameters considered as multiple nuclei. Considering the established rules, only a small percentage of the study area is considered suitable for future urban development. This will highlight the role of geomorphologic elements in identifying natural constraints in the future development of this city and the proper location of urban development. Conclusion The results obtained from the analysis of the required spatial data show that the entire development area with an area of about 32648.067 acres is located in the southeast and northern part of Baharestan when by considering this range and not considering the areas that are ineffective in providing proper land suitable for development, the range of about 2800.717 hectares is considered for planning future development of Baharestan city; Also, in the new range, avoiding the creation of zones and areas with inappropriate width would be avoided as it increases infrastructure costs. Also, in the new proposed range, the creation of zones and areas with Inappropriate width is avoided because it increases infrastructure costs. However, due to the lack of suitable areas for the future development of the city, it is necessary to make a serious review of urban development plans. Also, urban planners should allocate deserted and deserted areas of the study area according to geomorphologic criteria to priority applications and, as far as possible, observe the vertical expansion of the city in accordance with technical criteria, in order to maintain a balance between supply and demand for housing. Provide sustainable urban development.