پویش جمعیتی و الگوهای پوشش زمین در منطقه کلان ‌شهری اصفهان

رشد شتابان جمعیت شهری و تمرکز فزاینده آن در مناطق کلان ‌شهری، از بارزترین تحولات سکونتگاه‌های ایران معاصر است. پویش‌های فضایی - زمانی جمعیت، منجر به تغییرات پیچیده‌ای بر الگوهای پوشش زمین شده است. این مقاله با هدف بررسی و تحلیل تحولات فضایی - زمانی جمعیت شهری و الگوهای پوشش زمین ناشی از آن در چند دهه اخیر در منطقه کلان‌شهری اصفهان صورت گرفته است. روش تحقیق در این پژوهش توصیفی-تحلیلی است و با استفاده از تحلیل داده‌های سرشماری و آمار بلوک‌های شهری همچنین روش طبقه‌بندی تصاویر ماهواره لندست انجام‌شده است. یافته‌های پژوهش نشان می‌دهد در طی دهه‌های اخیر افزایش مطلق جمعیت شهری از محدوده 35 کیلومتری به محدوده 25 کیلومتری شهر اصفهان رسیده است. همچنین نتایج نشان می‌دهد که پویش فضایی - زمانی جمعیت شهری در منطقه کلان‌شهری اصفهان در مرحله تمرکزگرایی و توسعه گسترده قرار دارد. متناسب با پویش فضایی - زمانی جمعیت شهری، الگوی تغییرات پوشش زمین نیز دستخوش تحولات گسترده‌ای شده است و مهم‌ترین الگوی رشد شهری ناشی از تحولات جمعیتی در منطقه کلان‌شهری اصفهان حاکی از آن است که الگوی نیمه‌متمرکز این منطقه در دهه 1360 به سمت الگویی متمرکز و فشرده در دهه 1390 سوق پیداکرده است.

population survey and land cover patterns in isfahan metropolitan area

the rapid growth of the urban population and its increasing concentration in metropolitan areas is one of the most obvious developments in the settlements of contemporary iran. spatio-temporal population movements have led to complex changes in land cover patterns. this article aims to investigate and analyze the spatial-temporal changes in the urban population and the resulting land cover patterns in the last few decades in the metropolitan area of isfahan. the research method in this research is descriptive-analytical, and by using the analysis of census data and statistics of urban blocks, as well as the method of classification of landsat satellite images, it has been done. the findings of the research show that during recent decades, the absolute increase of the urban population has reached the area of 35 km to the area of 25 km of isfahan city. the results show that the spatial-temporal movement of the urban population in the isfahan metropolitan area is in the stage of centralization and extensive development. according to the spatio-temporal movement of the urban population, the land cover pattern has also undergone extensive changes. the most important pattern of urban growth resulting from demographic changes in the metropolitan area of isfahan indicates that the semi-centralized pattern of this region in the 1981s turned into a centralized pattern and was pushed in the 2011s.extended abstractintroductionthe rapid growth campaign around isfahan took various forms, such as the expansion of surrounding cities, the transformation of villages into cities, the destruction of some villages, the creation of new cities, and the development of countless industrial towns. as a result of these developments, firstly, the urban centers around isfahan expanded greatly, and secondly, with the extensive development of the extra-urban communication network, the economic, social, and physical-spatial relations between isfahan and the neighboring cities entered a new stage in which finally led to the formation of the metropolitan area of isfahan. methodologythe data for the study of population changes in isfahan metropolitan area are the data of the general population and housing census of iran, which was collected from 1956 to 2016 on a ten-year basis. the present research method is based on the developmental-applicative goal and descriptive-analytical methodology based on library studies and field investigations. this research aims to investigate the spatial-temporal developments of population growth and urban development in the metropolitan area of isfahan from 1986 in a period of thirty years to 2016. land cover maps have been produced using tm and etm + satellite images in 1986 and 2016, and envi software has been used for pre-processing, processing, and subsequent calculations. after classifying the images into four main classes, including built-up land, barren land, vegetation, and water, a visual method was used to improve the classification results. the results showed that the overall accuracy of classification results of satellite images in 1986 and 2016 is 88% and 91%, respectively. results and discussionthe investigation of spatial-temporal patterns of land cover in isfahan metropolitan area shows that in 1986, built-up lands with an area of about 130 square kilometers (13000 hectares) covered 0.42% of the area. the main focus of the lands built in 1986 was in the metropolis of isfahan. in 2016, with the passing of 30 years, considerable changes are taking place in the metropolitan area of isfahan. the built-up area has increased significantly to more than 617 square kilometers, which is 2.01% of the isfahan metropolitan area, and compared to 2016, it has experienced an almost 5-fold growth.