نوع مقاله : مقاله پژوهشی

نویسندگان

• حسن محمدیان مصمم ¹
• پویا جودی گل لر ²

¹ استادیار گروه شهرسازی، دانشکده معماری و شهرسازی، دانشگاه هنر اصفهان، اصفهان، ایران

² استادیار گروه مهندسی فضای سبز، دانشکده کشاورزی، دانشگاه تبریز، تبریز، ایران.

چکیده

برنامه‌ریزان شهری و منطقه‌ای در کشور ما، از تأمین یکی از بنیادی‌ترین نیازهای شهروندان که همواره کاتالیز دگردیسی اجتماعی و هویت فرهنگی و توسعه اقتصادی بوده (یعنی غذا) تقریباً غفلت کرده و تمایلی به درگیری و مشارکت در زمینه مسائل آن را ندارند. بدین‌سان جدایی اجتماعی _ فضایی فزاینده شهروندان از نظام‌های غذایی رخ داده و این در حالی است که در سرتاسر تاریخ، دفاع و کنترل تأمین غذا شالوده پیدایش، تکامل و حیات شهرهای ایران را شکل داده و نقشی بنیادین در توسعه جامعه‌گانی ایفا نموده و شرط لازمِ بقا و رفاه آنها بوده است. بر این اساس، پژوهش حاضر، با هدف نیل به امنیت‌غذایی و پایداری نظام غذایی در منطقه کلانشهری تهران و با بهره‌گیری از وضعیت هستی‌شناسی میانجی، معرفت‌شناسی فلسفه آزاد و روش ترکیبی و رویکرد پراگماتیک آن، ابتدا به مفهوم‌سازی امنیت غذایی، نظام غذایی شهری، دگردیسی فضایی و تشریح نقش و رسالت برنامه‌ریزان شهری در مسئله غذا پرداخته و سپس با هدف مشخص کردن نقاط اهرمی و عرصه‌های مداخله برنامه‌ریزان شهری و منطقه‌ای، به تحلیل دگردیسی‌های فضایی منطقه کلانشهری تهران طی چند دهه گذشته و اثرات آن بر نظام غذایی با مدل معادلات ساختاری واریانس_محور پرداخته است. نتایج نشان می‌دهد که این منطقه دگردیسی‌های فضایی چشمگیری را تجربه کرده و این تحولات در مجموع اثر منفی بر نظام غذایی منطقه نداشته است؛ اما در زیرلایه‌های «فیزیکی» و «فعالیت‌ها و ویژگی‌های جامعه و اشتغال»، اثر منفی داشته و پایداری نظام غذایی را به مخاطره انداخته است. در نهایت با جمع‌بندی مفاهیم نظری و مسائل ناشی از کنش متقابل دگردیسی‌های فضایی منطقه کلانشهری تهران و زیرلایه‌ها، سیاست‌ها و راهکارهایی در جهت بهبود نظام غذایی منطقه پیشنهاد داده شده است.

کلیدواژه‌ها

• امنیت‌غذایی
• نظام غذایی
• دگردیسی‌های فضایی
• منطقه کلانشهری تهران

موضوعات

• زیست پذیری شهری

عنوان مقاله [English]

Impacts of Spatial Transformation on the Food System of the Tehran Metropolitan Region

نویسندگان [English]

• Hassan Mohammadian Mosammam ¹
• pouya Joodi Gollar ²

¹ Department of Urban Planning and design, Faculty of Architecture and Urban Planning, Art University of Isfahan, Isfahan, Iran.

² Department of Landscape Engineering, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.

چکیده [English]

Highlights

Overall spatial transformation did not undermine the food system, but physical and socio-economic changes threatened its sustainability.
The Tehran metropolitan region has experienced significant spatial transformations.
Not all dimensions of spatial transformation exert the same influence on food systems.
Urban and regional planning can play a strategic role in strengthening food security.

 
Introduction
The world’s population has reached 8.2 billion and is projected to increase to 10.3 billion by the mid-2080s. Approximately 757 million people experience hunger, while 2.8 billion cannot afford a healthy diet. Iran faces rapid urban growth, the loss of fertile agricultural land, water scarcity, recurrent droughts, land subsidence, dependence on imports, and increasing food insecurity. Yet food remains largely absent from urban and regional planning agendas. This omission is particularly important in the Tehran Metropolitan Region, which has undergone profound spatial transformation. Covering 18,815 km² and containing approximately 15.98 million people, the region has experienced rapid urbanization, fragmented metropolitan governance, agricultural land conversion, environmental degradation, and socio-spatial inequalities. This study conceptualizes food security, food systems, and spatial transformation; identifies major multidecadal transformations in the region; and evaluates their effects on the regional food system. The main hypothesis is that recent spatial transformations have contributed to food-system unsustainability.
Theoretical Framework
The food system is conceptualized as a socio-ecological system formed through interactions between biophysical and social environments. Its principal stages comprise inputs, production, processing, transportation and distribution, consumption, and recycling and disposal. Spatial transformation is understood as multidimensional change in the organization of urban and regional systems over time. The analysis distinguishes three interrelated layers: the physical layer; the network layer; and the layer of activities and characteristics of society and employment. This framework allows the aggregate effect of metropolitan transformation to be distinguished from the contrasting effects of its constituent dimensions.
Methodology
This applied research adopted a pragmatic mixed-methods design combining documentary analysis with a web-based survey. Purposive sampling was used to incorporate the perspectives of actors and researchers associated with food-system issues. A 10-member expert panel evaluated the validity and reliability of the research instruments. The Content Validity Ratio was 0.74 for spatial-transformation indicators and 0.77 for food-system stages; the corresponding Content Validity Index values were 0.81 and 0.80, respectively. Cronbach’s alpha was 0.712 for spatial transformation and 0.835 for the food system. The final assessment comprised 70 indicators: 9 physicals, 19 network, and 42 related to activities and characteristics of society and employment. Descriptive and inferential statistical analyses included one-sample t tests, correlation analysis, and variance-based structural equation modeling using Partial Least Squares (PLS-SEM). Tehran and Alborz Provinces were treated as a single case representing the Tehran Metropolitan Region/foodshed because relevant official data are primarily compiled within administrative boundaries.
Results and Discussion
Substantial transformation occurred across all three spatial layers. In the physical layer, the region experienced declining biodiversity, reduced renewable water availability, increased water consumption, groundwater deficits, the drying of shallow wells, springs, and qanats, soil erosion, and growing pressure on agricultural land and ecological capacity. In the network layer, transportation and energy infrastructure expanded, the urban system moved toward greater polycentricity, and regional flows became denser, more multidirectional, and more evenly distributed. In the activities and characteristics of society and employment layer, major changes included population growth and density, demographic restructuring, economic and employment shifts, institutional fragmentation, rising greenhouse gas emissions, and the continued conversion of agricultural land and orchards.
PLS-SEM identified a strong direct relationship between overall spatial transformation and the food system (β = 0.957; t = 11.210). However, the hypothesis that spatial transformation had an overall negative effect was rejected; the aggregate directional effect was interpreted as neither clearly positive nor negative, with a path coefficient of 0.425 and t = 1.96. Disaggregated analysis revealed sharply differentiated effects. Transformation of the physical layer had a strong negative effect on the food system (β = −0.946; t = 2.012), whereas transformation of the network layer had a strong positive effect (β = 0.805; t = 16.65). Transformation of activities and characteristics of society and employment also had a strong negative effect (β = −0.926; t = 62.04). Thus, the aggregate relationship masks opposing mechanisms: network transformation supports food-system functioning, whereas physical-environmental degradation and adverse socioeconomic and employment-related transformations threaten sustainability.
Conclusion
The study demonstrates that food should be treated as an integral component of urban and regional planning rather than as an issue confined to agriculture or the economy. Although spatial transformation as a whole was not found to exert a net negative effect on the food system of the Tehran Metropolitan Region, the physical layer and the activities and characteristics of society and employment generated substantial sustainability pressures. Planning priorities therefore include integrating food into urban and regional planning, establishing an integrated institutional framework at the city-region scale, protecting agricultural land through coherent zoning, strengthening urban and peri-urban agriculture, managing water, soil, and land resources sustainably, developing shorter supply chains and local and regional food-distribution hubs, recovering organic waste for safe and productive reuse, promoting sustainable consumption, and strengthening a polycentric regional spatial structure. The central contribution is to demonstrate that spatial transformation does not affect food systems uniformly; its effects are layer-specific and require differentiated interventions that distinguish transformations supporting food-system functioning from those undermining long-term sustainability.

کلیدواژه‌ها [English]

• food security
• food system
• spatial transformations
• Tehran metropolitan area