شناسایی مناطق مستعد توسعه میان افزا با استفاده از دورسنجی، مورد مطالعه: کلانشهر اهواز (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
زمانی که در یک محدوده زیستی، پدیده پراکنده رویی کالبدی پدیدار شود، می توان گفت که درون شهر فضاهای بلااستفاده، رها شده، ناکارآمد و فرسوده شکل می گیرد؛ از این روست که توجه و برنامه ریزی برای استفاده از این فضاها اهمیت پیدا می کند. در واقع رشد هوشمند شهری یکی از راهکارهای اساسی در پاسخ به پراکنده رویی است. بنابراین توجه به اصول توسعه میان افزا در محدوده های دارای ظرفیت شهر مانند بافت های فرسوده، مخروبه ها، اراضی بایر و بافت های ناکارآمد شهری می تواند به عنوان یکی از راهبرد های اساسی برای دستیابی به رشد هوشمند شهری کمک نماید. هدف پژوهش حاضر نیز شناسایی محدوده های با قابلیت توسعه درون زا با تأکید بر شاخص های قابل دستیابی از داده های دورسنجی شامل بخش های فرسوده و زمین های بایر در محدوده قانونی شهر اهواز است. برای این منظور پس از تهیه و استانداردسازی تصاویر ماهواره ای لندست (سنجنده ETM) و IRS (سنجنده 1D)، با استفاده از مدل های WS (تقسیم حوزه ای) و MLC (بیشترین همانندی) به طبقه بندی و استخراج بافت های مورد نظر پرداخته و سپس در GIS با ترکیب خروجی های پیشین، نقشه کلاسه بندی مناطق قابل پیشنهاد توسعه میان افزا ارائه گردیده است. نتایج تحقیق نشان داد که از مساحت 18 هزار و 650 هکتاری محدوده قانونی شهر اهواز، بیش از شش هزار و 726 هکتار (شامل مناطق شناسایی شده بایر و بافت فرسوده) قابلیت توسعه میان افزا را دارند. این مقدار 36.2درصد از مساحت شهر را شامل می شود. همچنین از کل پهنه پیشنهادی برای توسعه میان افزای اهواز، در بافت های فرسوده و اراضی بایر، بیشترین مساحت متعلق به اراضی بایر با بیش از پنج هزار و 768 هکتار و کمترین مقادیر مربوط به قطعات بافت فرسوده با بیش از 958 هکتار، به ترتیب با 85.7 و 14.3 درصد از کل مناطق اختصاص یافته به توسعه میان افزای منطقه مورد پژوهش بوده است.Identifying potential areas for infill development using Remote Sensing: Ahvaz metropolis
Highlights - When infill occurs in a scattered pad area, it can be said that an unused, inefficient space is formed in the city. - Of the 18,650-hectare legal area of the city of Ahvaz, more than 6,726 hectares has the possibility of infill development. - Infill development with a suitable design can be a new type of development with a mixed residential structure and residents with different income levels. Introduction In the country of Iran, while the growth and development patterns of towns were determined by local, endogenous parameters, there was some balance between life and the growth of urban economy. As exogenous factors began to play a role, however, some cities grew extremely and irregularly. The city of Ahvaz has undergone extensive physical-spatial changes due to the increase in population, the development of oil industries, the centrality of the province, the establishment of urban services, and the attraction of the residents of the cities and villages of the province in the past decades. This caused the uneven expansion of the city and the emergence of the phenomenon of dispersion therein. The physical parameters that trigger development in Ahvaz include industrial towns, military lands, the airport complex and its facilities, the academic functions of the city, its role as the main communication pathway, the market line to the east of the river, and the integration of suburban areas. These factors have caused many domestic capacities and potentials to remain unused, such as distressed and less developed or undeveloped lands in the city. Therefore, according to the current conditions in Ahvaz, it is a necessity to know about the areas and regions that are prone to infill development, in order to present plans to prevent the phenomenon of dispersion and realization of infill development. Theoretical Framework To describe the notion of infill development, a large number of definitions have been proposed. The most common cause in the world is people’s residence in less wild areas of the city. Given that civilization has often happened in developing countries, and that many of the urban districts in these countries have undergone enormous growth that could be efficient in regard to the key principles of development, a three-dimensional strategy could be adopted for the development of a vast area, involving:1- new construction on a land that has not been developed, or, at least, cultivated, 2- physical rehabilitation of the current unusable buildings, and 3- compatibility with the forms and functions of these buildings. Methodology The data used in this research includes Landsat and IRS satellite images, which were processed in the PCI Geomatica environment. The first stage of pre-processing (geometric correction) in this research includes integration of the coordinates of the prepared images. For this purpose, 25 control points were used. In order to better distinguish body spaces from shadows, the histogram equalization operation was also performed on the corresponding images. Then, the distressed fabric map was extracted using the WS model. MLC classification was applied to the images in order to generate and present a map of empty and barren lands in Ahvaz. For this purpose, different bands of two types of data were merged (fused) with image-merging operations to obtain the best combination of bands for classification. Results and Discussion The statistical investigations showed that of the total 18,650-hectare area of Ahvaz, 958.2 hectares was identified as distressed fabric, which makes up 5.13% of the city. The identified areas mostly correspond to the central parts of the city (the border between Salman Farsi and Taleghani Streets) and the old fabric around the Ali Mahziar Shrine. Moreover, in almost all the eight districts of the city, more or less scattered parts were identified as distressed fabric. Conclusion The results of the research showed that of the 18650-hectare legal area of Ahvaz, more than 6726 hectares (including the identified barren areas and distressed fabric) have the potentials for infill development. This value represents 36.2% of the city’s area, which is a relatively large ratio. Furthermore, over the entire area prone to infill development in Ahvaz, including distressed fabric and barren lands, the largest area concerns barren lands, with more than 5768 hectares, and the lowest values pertain to parts of the distressed fabric, with more than 958 hectares, representing 85.7% and 14.3%, respectively, of the entire area studied as prone to infill development. The results concerning the distribution of distressed fabric as identified in this research show that Municipal Districts One and Seven exhibit the largest values, with 3197360 and 3231110 square meters, representing 33.36% and 33.75% of the total distressed fabric of Ahvaz, respectively, and District Five has the smallest values, with 5850 square meters, making up 0.06%. These statistics are highly consistent with the field data, because Districts Seven and One of Ahvaz are considered as the old parts of the city and mainly contain the historic fabric. On the other hand, District Two, with a little more than 1720 hectares, and District One, with about 80 hectares, representing 28.5% and 0.3%, respectively, are known as the most and least severely barren and empty lands. The data in this section seem logical because District One (Old Ahvaz) is considered as part of the historic fabric and the primary, central core of Ahvaz, so the least severely abandoned, barren, and empty land occurs in this area.
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