تحلیل و پیش بینی ساختار فضایی منطقه کلانشهری مشهد طی دوره 1420-1375

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشکده هنر و معماری، دانشگاه تربیت مدرس

2 کارشناس ارشد برنامه ریزی منطقه ای، پژوهشگر

چکیده

در چند دهه ی اخیر مناطق کلانشهری کشور دچار تغییر و تحولاتِ گسترده ای شده اند. منطقه کلانشهری مشهد نیز به عنوان یکی از مهمترین قطبهای توسعه در شرق کشور در حال تجربه این تحولات می باشد. این منطقه با بیش از سه میلیون نفر جمعیت، از عدم تعادل فضایی، پراکنده رویی و تمرکزِ شدید رنج می برد. پیامد منطقیِ این تمرکز، رشد کالبدی شهر مرکزی، پدیدار شدنِ نابرابری های اجتماعی و اقتصادی، تخریبِ اراضی سبز و کشاورزی، بورس بازیِ زمین و رانت خواری، آسیب هایِ اکولوژیکی و... می باشد. از این رو تحلیل و پیش بینی ساختار فضایی یکپارچه در این منطقه ضرورت دارد. برای این منظور با تکیه بر بعدِ ریخت‌شناسی ساختار فضایی، ابتدا تغییراتِ کاربری اراضی برای دو دوره 1405 و 1420 شبیه‌سازی می‌شود. در گام دوم، با استفاده از سه شاخص توزیع، خوشه‌بندی و تجمع، بر پایه داده‌های پیش‌بینی شده جمعیت در سال‌های مزبور، سیمای فضایی منطقه ترسیم می‌گردد. نتایج تحقیق نشان می‌دهد که روندِ تغییرات به سمتِ از بین رفتنِ هر چه بیشترِ اراضی کشاورزی و مراتع پیش می‌رود، به طوری که در سال 1405 مساحتی معادل 247 کیلومترمربع به مساحتِ اراضی ساخته شده در سال 1390 اضافه می‌شود، در سال 1420 این رقم به 1004 کیلومترمربع می رسد. نتایج حاصل از تحلیل داده‌های جمعیت و اشتغال بر اساس سه شاخصِ مزبور، نیز حاکی از پیش رفتنِ منطقه به ‌سوی قطبیتِ بیشتر است. لذا لازم است نظام مدیریتِ منطقه‌ای در راستای جلوگیری از تحقق این پیامدها تمهیدات لازمی بیندیشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Analysis and Forecasting of the Integrated Spatial Structure in Mashhad Metropolitan Region in the Period 1996- 2041

نویسندگان [English]

  • Hashem Dadashpoor 1
  • Nariman Jahanzad 2
  • Homa Jalili 2
چکیده [English]

In the last few decades, city-regions have faced considerable changes. Mashhad metropolitan region as one of the most important development centres in the eastern region of Iran, has experienced great spatial changes which have brought about many spatial problems. This city alone has more than 75 percent of the population of the wider Mashhad region as well as accounts for approximately 90 percent of the added value of that region. The explanatory indices used in this area indicate an intense imbalance and centralization of capital and power in the area. The logical consequence of this imbalance have led to urban sprawl and increasing accumulation of capital. This sprawl have had several consequences such as the destruction of green and agriculture lands, land speculation, increase in environmental pollutions, ecological destruction and mismatch of the developed land with the natural potentials of those lands. On this basis, it is necessary to identify the future spatial changes in this region. Accordingly, this study has two parts. The first part is based on the morphological dimension of spatial structure and simulates  future land use changes for the years 2026 and 2041. In doing so, the CA model was associated with ANN algorithm. The simulation process was run in QGis 2.4 environment. In the second stage, by using distribution, clustering and concentration indicators and based on the predicted data of population and employment in the aforementioned years, the spatial configuration of the region was drawn. The results of distribution indices show that from 1996 to 2041 the value of entropy coefficient will decreased which indicates polarization of the population and employment in the region. The findings of   the spatial changes analysis by K-Ripley function indicate that at short distances, population and employment distribution will change in a dispersing manner, and at long distances, concentration in population and employment will be intensified. Finally, concentration indices show that the Mashhad metropolitan area does not have any spatial concentration patterns, and population and employment will distribute randomly. The results show that the growth process in the region is proceeding in a devastating manner as vast amounts of agricultural lands and pastures will continue to be ruined. In the year 2026, 247 Km2 of these lands will be built on and green spaces will  tranform into urban lands. This  amount will be equal to 1004 Km2 in the year 2041.
In conclusion, the continuation of the existing growth will lead to irreparable consequences in the area.Future spatial changes will lead to consuming agricultural lands and grasslands and will deteriorate rural settlements. The continuation of the present development of urban settlements and land-use changes might cause environmental disasters such as a water crisis, increased air pollution and pressure on infrastructure which. in turn will lead to irreparable socio-economic damage and human crises like riots, crimes and vandalism. Thus, it is necessary that planning systems pay attention to reasonable management of growth.

کلیدواژه‌ها [English]

  • spatial structure
  • Metropolitan Region
  • Land Use Change
  • Cellular Automata
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