تحليلي بر روند گسترش كالبدي شهر و اثرات آن بر كيفيت محيط زيست شهري مورد پژوهش: شهر بابلسر

Analyzing the Physical Expansion of City and Its Impact on the Quality of Urban Environment (Case Study: Babolsar City)

اهداف: در نظام سرمايه داري معاصر، شهر به عنوان مكان مناسب زندگي به شمار مي آيد. رسوخ و نفوذ فرهنگ سرمايه داري در در حال توسعه ازجمله ايران، موجب تمركز شهري ناهمگون و رشد شتابان جمعيت شهري و در نهايت مشكلات زيست محيطي است. هدف اين مقاله، بررسي اثرات گسترش شهري بر كيفيت محيط شهر بابلسر است. روش: روش شناسي اين تحقيق مبتني بر رويكردهاي توصيفي- تحليلي است كه بطور گسترده اي از مدل هاي آماري جهت سنجش اثرات توسعه فيزيكي شهر بر كيفيت محيط استفاده شده است. بعضي از اين مدل ها شامل انتروپي شانون، هلدرن و همچنين آزمون هاي كندال و گاما بوده است. يافته ها/ نتايج: نتايج نشان مي دهد كه در كنار تاييد رابطه معني دار بين گسترش كالبدي و كيفيت سه گويه ديگر(خدمات رفاهي- اجتماعي، ‌خدمات تجاري و خدمات تفريحي)، محلات سه، دو و چهار داراي شرايط بسيار بهتري از حيث كيفيت زيست محيطي نسبت به ساير محله ها هستند كه درواقع با پايگاه اجتماعي، اقتصادي و فرهنگي ساكنين محله هاي مذكور، ارتباط مستقيم دارد. نتيجه گيري: بنابر اين به نظر مي رسد كنترل و مهار مناسب رشد فيزيكي شهر از جمله سياست هايي كه متوليان امور محلي بايد بدان عمل نمايند. همانطور كه بديهي است حفظ اراضي حاصلخيز پيرامون شهر در پايداري محيط زيست كمك كننده خواهد بود.

1.INTRODUCTION The trend of urbanization and urban expansion has caused many unpleasant effects in the different cities of Iran, which are mainly rooted in the socio-economic transitions of these areas. Extensive environmental and geographical changes have led to the destruction of agricultural lands, encroachment of cities into high slops and, integration of rural areas into urban structures. Such condition has fueled environmental problems and natural disasters like urban floods, thus increasing the costs of urban service provision and maintenance. Babolsar city with a variety of attractions has experienced rapid growth due to the growth of high population and tourism activities. This trend has multiplied the unplanned construction of many buildings, transforming the urban landscapes especially in the vicinity of agricultural lands in the outskirt and the coastal areas of the city. Thus, the appropriate planning and management of urban spatial structure is essential to the management of the city development. 2. THEORETICAL FRAMEWORK Urban environment consists of a variety of mutually-related natural and man-made subsets as well as human society. Today, in keeping with physical expansion of cities in form of extended scope and vertical growth, this has provided a fertile research ground for urban studies Generally, there are many factors that can influence the physical growth and population of cities the most important of which are the natural population growth, increased rural-urban migration, highlighted administrative- political role of urban centers and concentration of commercial, infrastructural and public services in cities, which have created widespread environmental changes in the quality of urban areas. It seems the present pattern of city expansion undermines the principles of sustainable development in the area. 3. METHODOLOGY This research adopts a descriptive- analytical approach. The data were obtained after a review of existing documents and national censuses. A field work was undertaken to complete the research questionnaires and the samples were distributed randomly among households in the neighboring cities. To analyze the pattern of city expansion, Shannon entropy and Holdren models were applied. The focus was on the environmental quality of different neighborhoods with regard to the main objectives of the research. 4. RESULTS & DISCUSSION The results of Shannon entropy in the years 2000 and 2010 revealed significant urban sprawl which not only had soiled the physical structure of the city but also eliminated agricultural lands. The results showed that 60 percent of the city growth was commensurate with the population growth while the other 40 percent was the result of unbalanced growth or sprawl. Also, the analysis of objective indicators of urban environment, including physical functional and contextual characteristics in eleven districts showed that the expansion of Babolsar, as a determining factor, had influenced all aspects of urban life quality. Overall, Districts 3, 2 and 4 were superior to other areas in terms of conditions of urban life quality. In fact these districts had great socio-economic and cultural status which contributed to the quality of urban environments. 5. CONCLUSIONS & SUGGESTIONS Evidence shows that show that the physical expansion of cities in the recent decades has produced undesirable economic, social and environmental effects, highlighting the importance of sustainable development and environment preservation. The physical expansion of cities in the north of Iran has brought about widespread changes in the agricultural land use, degrading environmental quality. This article Attempts to investigate the impacts of physical growth of Babolsar on the quality of city environment different districts and to determine the pattern of physical expansion. The results showed that Babolsar city had been subject to a high physical growth of 40 percent mainly in form of urban sprawl. Also, the analysis of questionnaires revealed that besides a significant correlation between the physical expansion of the city and the quality of three indicators (welfare- social services, commercial services and recreational services), Districts 3, 2 and 4 were superior in terms of environmental quality. In fact, these districts had improved socio-economic and cultural status which contributed to the higher quality of urban environments.