بررسي تطبيقي پراكنده‌رويي در سه شهر مياني ايران‎؛ ‎‎نمونه موردي: شهرهاي اردبيل، سنندج، كاشان

Comparative Study of City Sprawl in Three Middle Range Cities of Iran: Ardabil, Sanandaj and Kashan

پراكنده‌روييِ شهري به عنوان يكي از مهم‌ترين چالش‌ها و موضوعات سياست‌گذاري فضايي، به‌ويژه از نيمه دوم قرن بيستم در دستور كار حكومت‌هاي بسياري از كشورها قرار گرفته است. چنين الگويي موجب شكل‌گيري نوعي از گسترش مي‌شود كه به دليل عدم اختلاط كاربري‌ها، فقدان مركزيت و ضعف و ناكارآمدي در دسترسي، از يك سو به اتلاف منابع و انرژي دامن مي‌زند (مانند زمين براي ساخت‌وساز، و انرژي براي حمل‌ونقل بين نقاط)؛ و از سوي ديگر آلاينده‌هاي مختلف محيطي توليد مي‌كند. به نظر مي‌رسد مفهومِ پراكنده‌رويي، با تعاريف اغلب متكي بر منابع كشورهاي غربي، در ايران در قالب الگوهاي متفاوتي ظاهر بشود. هدف اين مقاله اندازه‌گيري و تعريف مشخصه‌هاي پراكنده‌رويي شهري در سه شهر مياني اردبيل و كاشان و سنندج، براساس چارچوب نظري مرجح در شرايط ايران است. در اين مطالعه از داده‌هاي تحت سيستم اطلاعات جغرافيايي، روش تحليل عاملي و SPSS استفاده شده است. به نظر مي‌رسد در الگوهاي پراكنده‌رويي شهري در شهرهاي مياني، برخلاف كشورهاي توسعه‌يافته غربي كه در آنها توسعه كم‌تراكم مشخصه اصلي است، فقدان مركزيت و ضعف اختلاط كاربري عمده‌ترين مشخصه‌هاي تعريف اين پراكنده‌رويي‌اند.

The term “urban sprawl” is often used as a synonym for undesired low-density or otherwise unplanned urban spatial development. More often, though, sprawl is defined in terms of “undesirable” land-use patterns—whether scattered development, leapfrog development (a type of scattered development that assumes a mono centric city), strip or ribbon development, or continuous low-density development. However, the precise definition, as well as its desirability, is debated. From mid of twenty century, urban sprawl has become as a main subject and challenge in spatial policy making agenda of most of governments. In this kind of urban expansion, land as a main source of development is utilized in a higher rate than population growth. Such kinds of development, for lack of mixed land use, lack of centrality and inefficiency in accessibility, etc. leads to wasting non-recyclable resources and energies (resources like land for developments and energy for center-periphery commuting) on the one hand, and polluting environment as their impacts on the other hand. However, intensity and substance and physical forms of urban Sprawl would be different dependent upon levels of economic and social development of countries and their planning system. Major factors which caused the urban sprawl in Iran were parallel with starting exogenous development process in the country. Rapid urbanization fueled by motorization, rapid growth of population and rural –urban immigration, central government ineffective land policy, land speculation, etc. prevent from infill development and led to land uselessness within cities as well as increasing urban sprawl in suburbs. All these processes led to a massive transformation of agricultural land into urban land-uses all over the country and provided some evidences that urban is taking place as a pattern of development. So, it seems that the mentioned pattern in our country is different from its origins (in American cities). Although the urban sprawl began four decades ago in Iran, but has yet to be empirically measured or characterized. Present paper aims at defining and measuring the characteristics of urban sprawl in three middle range Iranian cities according to a preferred theoretical framework inferred from literature review. In case studies, the authors have used GIS based data and methods like factor analysis and SPSS for measuring their urban development characteristics and defining the areas that show higher indices of sprawl development. Research findings indicate that lack of centrality and low level of mixed land use are the main factors defining urban sprawl development in the case studies. This is in contrast with western countriesʹ situation in which low density development is the main characteristic of sprawl. The findings show that the highest rate of urban sprawl is observed in the areas of Sanandadj and Ardabil that were developed and affected directly by the governmental land policies.