ارزیابی شهر جدید سهند با استفاده از سیستم ظرفیت برد شهری(u.c.c.a.s)

طرح مسئله: ازجمله چالش‌های اصلی در شهرهای بزرگ به‌ویژه کلان‌شهرها افزایش بی‌رویۀ جمعیت بدون توجه به ظرفیت خدمات و تاسیسات، پاسخ‌گو به نیازهای اساسی شهروندان است. ایجاد رابطه‌ای متعادل بین جمعیت و ظرفیت منابع مورداستفاده به‌منظور پایداری منابع باکیفیت استاندارد برای نسل‌های آتی، ضرورت توجه به مقولۀ ظرفیت برد را در تدوین برنامه‌های شهری آشکار می‌کند. ظرفیت برد نقش بسزایی در پایداری محیط‌های شهری دارد، به ایجاد تعادل بین میزان جمعیت و منابع موجود در شهر و به تبع آن مدیریت بهینۀ شهری کمک می‌کند. هدف: شناخت عوامل موثر بر پایداری زیستی، سنجش ظرفیت جمعیت‌پذیری و ارائۀ راهبردهای مدیریت برای بهبود شهر از اهداف این پژوهش است. روش پژوهش: پژوهش حاضر توسعه‌ای– کاربردی و روش تحقیق از نوع تحلیلی _ توصیفی است. اطلاعات موردنیاز پژوهش به روش اسنادی- کتابخانه‌ای و میدانی تهیه شده است. برای بی‌مقیاس‌سازی شاخص‌های (جمعیت، آب، برق و فضای سبز) از روش فازی استفاده و سپس شاخص‌های مذکور در محیط نرم‌افزار arcgis با روش‌های آمارۀ گیتس اردجی، تحلیل خود همبستگی فضایی موران، پهنه‌بندی تکنیک موریس و مدل عدد فشار تجزیه‌وتحلیل شده است. نتایج و نوآوری پژوهش: نتایج نشان‌دهندۀ آن است که مقدار موران جمعیت، آب، برق و فضای سبز به‌ترتیب 0.17، 0.15، 0.15 و 0.03 است. به‌طوری که سه شاخص اول از الگوی خوشه‌ای قوی پیروی می‌کنند؛ در حالی که شاخص فضای سبز به‌صورت پراکنده در سطح شهر توزیع شده است. بیشترین توان جمعیت‌پذیری ظرفیت تحمل شاخص‌های آب، برق و فضای سبز به‌ترتیب برابر با 105639، 129121 و 528540 نفر است. براساس تحلیل‌های آستانۀ ظرفیت تحمل جمعیت، مصرف آب و توزیع برق شهر جدید سهند در بازۀ فشار بحرانی قرار گرفته است؛ در حالی که شاخص فضای سبز در آستانۀ مطلوب است. به‌طوری که در چندین سال اخیر شهر دارای سرانۀ فضای سبز بسیار خوبی بوده و ظرفیت تحمل آن بیش از 80 درصد است.

evaluation of the new city of sahand using the urban carrying capacity assessment system

among the main challenges in big cities, especially megacities, is the excessive increase in population regardless of the capacity of services and facilities to meet the basic needs of citizens. identifying the factors affecting biological sustainability, measuring population capacity, and providing management strategies to improve the city were among the goals of this research. the information needed for the research was prepared via document-library and field methods. the fuzzy method was used to descale the indicators of population, water, electricity, and green space. then, the mentioned indicators were used in the arcgis software environment with the methods of gates ardeji statistics, moran’s spatial autocorrelation analysis, morris technique zoning, together with the model. after analyzing the pressure number, the results showed that the moran values of population, water, electricity, and green space were 0.17, 0.15, 0.15, and 0.03, respectively. therefore, the first three indicators followed a strong cluster pattern, while the green space index was scattered and distributed in the surface of the city. the maximum capacity of the population, carrying capacity of water, electricity, and green space indicators were equal to 105639, 129121, and 528540 people, respectively. based on the analysis of population tolerance threshold, water consumption, and electricity distribution, the new city of sahand was in the critical pressure range, while the green space index was at the optimal threshold so that in the last several years, the city had had a very good green space per capita. its bearing capacity was more than 80%. introductionwith the growth of urbanization and urbanism, the problems of the urban environment have reached a critical level, while one of the most important issues in the today’s world is the problem of preserving the environment. to achieve sustainable urban development, it is necessary to establish appropriate laws and regulations and correctly implement them, as well as changing consumption patterns and environmental attitudes. the purpose of creating new cities can be attraction of the population overflow of cities, reduction of the economic activities of the mother city, regional development, and the use of natural resources, as well as optimal distribution of the population. in fact, these cities are created to help solve the economic, social, and environmental problems of big cities. therefore, creation of new cities is a response to &megalopolis& or excessive concentration of population and economic activities in big cities. the new city of sahand (tabriz) is an example of these new cities, which has been created to attract the overflowing population of tabriz metropolis with a high population density compared to other areas. the purpose of this research was to evaluate the urban range capacity system in the new city of sahand by relying on the indicators of population, water, electricity, and green space and trying to estimate the population capacity of the city from an environmental point of view and the amount of pressure on it besides determining which indicator can be applied in its planning. materials methodsthe information required for the research was collected by directly referring to the city institutions, such as new sahand city municipality, new sahand city development company, new city water and sewerage department, east azerbaijan power distribution company, etc., as well as studying documents and electronic library resources, and conducting field studies. the statistical population of the present study included the citizens of the new city of sahand. due to the fact that the statistical blocks were not ready to be obtained in 2022 from the data of the previous years (2012-2017), the population of the city in 2022 was fulfilled. the urban range capacity indicators studied in this research were population (population in 2017 and 2022), water (production and annual water consumption of the new city of sahand in 2022 in cubic meters), electricity (total number of subscribers in domestic, public, agricultural, and industrial sectors and other users, road lighting (based on people and energy consumption in 2022), and green space (areas of parks and green spaces based on each phase and number of the existing parks). these 4 indicators (population, water, electricity, and green space) were first descaled by the fuzzy method and then, the hot-cold spot method and moran’s spatial autocorrelation were used to analyze the spatial distribution of the urban range capacity system in the arc gis 10.8.1 software environment. the indicators used were measured and a consolidated index was obtained by using the morris zoning technique. finally, it was determined which phases of the new city of sahand had services and facilities and which ones lacked them. research findingsaccording to the general and housing population census of 2015, the new city of sahand had a population of 82494, while the city of tabriz as the mother city had a population of 1,558,693. the increase in the price of housing in the city of tabriz and appropriateness of its price in the new city of sahand, compared to the metropolitan city of tabriz, especially for the low and middle-income classes, as well as the policy of building mehr housing in the new city of sahand had greatly increased the population of the studied city so that the population growth rate of the studied city had reached from 12.66% during the years of 2007-2012 to more than 27.27% during the years 2012-2017. this rate had also increased greatly during the last 5 years according to the estimates. the population of the new city of sahand in 2022 had reached more than 275000 people. it should be noted that out of the total of 5 phases designed for this city, phase 5 had not yet been used and was empty. thus, the mentioned phase was defined as zero in the calculations and only phases 1, 2, 3, and 4 of the new city of sahand were analyzed in the analysis of hot and cold spots. discussion of results conclusiontoday, the dominant view in the field of sustainability of cities is that they should be able to provide a good quality of living for their citizens and be receptive to the population as much as possible. excessive density of population in urban environments is one of the most important factors in creating environmental problems in cities. in this research, according to the standards defined based on the indicators of population, water, electricity, and green space, evaluation of the urban range capacity system in the new city of sahand was done by using the method of hot-cold spots and spatial autocorrelation analysis. moran’s spatial autocorrelation analysis was used to determine the spatial distributions of the mentioned indicators for the existing 4 phases of the new city of sahand. the results showed that the moran’s values for the indices of population, water, electricity, and green space were 0.17, 0.15, 0.15, and 0.03, respectively. therefore, the first three indicators followed a cluster pattern, while the green space index was distributed in a scattered pattern throughout the city. accordingly, the threshold population capacity, water consumption, and electricity distribution of the new city of sahand were in the critical pressure range, while the green space index was on a favorable threshold; hence, the city had had a very good green space per capita in recent years and its tolerance capacity was more than 80%.