آشكارسازي دگرگوني كاربرد زمين: تحليل ويژگي‌هاي گسترش برنامه‌ريزي‌نشده در منطقة كلان‌شهري تهران

Revealing land-use transformation: Analysing specifications of unplanned growth in the metropolitan region of Tehran

گسترش كلان‌شهرها (يا بزرگ‌شهرها) به‌سوي محيط‌هاي پيراموني در دو وضعيت اصلي و انواع وضعيت‌هاي مياني اين دو وضعيت اصلي روي مي‌دهد. وضعيت نخست گسترش برنامه‌ريزي‌نشده و رهاشدگي و وضعيت دوم، وضعيتي مهار و هدايت‌شده است. انواع نامعلومي‌هايي كه در مسير و در فرآيند آشكارسازي و تحليل دگرگوني ساختار فضايي و كاربرد زمين در منطقة كلان‌شهري تهران وجود دارد؛ نشان از نبود استقرار و يا ناكارآمدي سازوكار برنامه‌ريزي در اين منطقة كلان‌شهري دارد. بر پايۀ آشكارسازي و تحليل دگرگوني‌ ساختار فضايي و كاربرد زمين در منطقة كلان‌شهري تهران مي‌توان به توليد پيشنهادهايي درخور شرايط موجود، به‌منظور استقرار سازوكاري براي پايش، بازبيني، و فرابيني اين دگرگوني‌ها پرداخت و نتايج آن را همچون سيستم‌هاي پشتيبان تصميم‌گيري دربرنامه‌ريزي و مديريت چنين منطقه‌هايي به‌كار بُرد. در اين مقاله با رويكرد توصيفي- تحليلي براي آشكارسازي دگرگوني ساختار فضايي و كاربرد زمين، بعنوان هدف اصلي مقاله، با استفاده از روش‌هاي اندازه‌گيري اندازۀ محيط ساخته‌شده در برابر فضاي باز، كه با تحليل محتواي پژوهش‌هاي مرتبط و با توجه به قيود داده‌هاي در دسترس انتخاب شده‌است، دگرگوني از دهة 1350 تا 1390 اندازه‌گيري گرديده. تحليل نتايج دگرگوني، و تحليل الگوواره‌هاي اصلي و فرعي گسترش منطقة كلان‌شهري تهران نشان مي‌دهد گرايش چگونگي گسترش اين منطقة كلان‌شهري به گسترش برنامه‌ريزي‌نشده است.

Problem under study: Metropolitan growth toward their peripheral environments and shaping the metropolitan regions occur in two major situations and various states amidst. One major form is unplanned and uncontrolled with unintended consequences. In the second situation, metropolitan growth is planned and directed towards pre-set goals, with an indication of the existence of a current and effective planning system. Ideal type of mentioned situations can be rarely found in more and less developed countries of the world, while most metropolitan areas experience their growth in situations that are in-between these two major situation. Absence of effective mechanism for survey, review, and monitoring of land-use transformation is one the characteristics of unplanned metropolitan growth. Lack of complete and integrated information system, and constraints on revealing and analysing spatial structure and land-use transformation, implies the absence or ineffectiveness of planning mechanism in the metropolitan region of Tehran, which is the geographical-administrative space under study in this article. Purpose: The purpose of this article is to make an attempt to revealing land-use transformation in the metropolitan regions and by reviewing and analysing relevant methods, to select an appropriate method for analysing the metropolitan region of Tehran. Reviewing and analysing the metropolitan region of Tehran in this article is restricted to planning and policy-making spheres. Based on the analysis for revealing land-use transformation in the metropolitan region of Tehran, some suggestions emerged to initiate suitable mechanism to survey, review, and monitor such transformations. A suggested mechanism could be used as a decision support system in the planning and management of metropolitan regions. Methodology: A descriptive-analytical approach, as an overall method that has been applied in this article, has conceived and adopted a three staged process of diagnosis and prognosis methods: First stage deals with the theoretical foundations and the technical aspects of the subject under study so that to find the appropriate guiding principles for the analysis bound for revealing land-use transformation in metropolitan regions. Second stage is concerned with formulating guiding principles that emerged in the first stage, and was with due consideration to the constraints related to access to the required information and the existence of accessible databases in order to find an appropriate method for the intended analysis of the metropolitan region of Tehran. Third stage is allocated to the application of the method that emerged in the second stage, in order to reveal land-use transformation along with analysing specifications of unplanned growth in the metropolitan region of Tehran. Achievement: Devising and applying an approach for analysing and revealing land-use transformation, due to the unplanned growth of Tehran towards its peripheral natural environment, is the main outcome and achievement of this article. Also, an emphasis has been put upon designing and establishing a planning and policy-making mechanism in the metropolitan regions, especially in the metropolitan region of Tehran, which would enable reducing, solving, or preventing the formation of problems related to the invasion of the natural environment by the metropolitan growth.