Remote Sensing and GIS Applications in Environmental Sciences

Spatio-temporal assessment of urban air pollution in Isfahan using ground monitoring and radar observations

Document Type : Original Article

Authors

Department of Physical Geography - Faculty of Geographical Sciences and Planning - University of Isfahan

10.22034/rsgi.2026.68897.1146

Abstract

Objective: Rapid urbanization and intensive industrial development have led to critical air pollution challenges in Iranian megacities, with Isfahan facing one of the most severe conditions. This study aims to analyze the spatiotemporal patterns of major air pollutants in Isfahan during 2018–2023.
Methods: We employed Sentinel-5P (TROPOMI) satellite data combined with ground-based monitoring stations to evaluate the spatial distribution and temporal trends of five key pollutants: nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), fine particulate matter (PM2.5), and the UV Aerosol Index (UAI). Spatial analyses were conducted to identify concentration gradients and pollution hotspots across urban districts.
Results: NO₂ and CO concentrations were consistently higher in central and northern areas, declining towards the east and south. SO₂ showed fluctuating spatial patterns across years, while UAI levels were mainly elevated in the eastern and northeastern districts. PM2.5 concentrations were also concentrated in central and northern zones. Temporally, a notable decline in NO₂, CO, PM2.5, and UAI levels occurred in 2020, coinciding with COVID-19 restrictions, followed by an increase in subsequent years as activities resumed.
Conclusions: The findings highlight the dominant role of anthropogenic sources, particularly traffic and industrial activities, in shaping air quality patterns in Isfahan. Integrating satellite and ground-based data provides a reliable approach for monitoring urban air pollution and offers a scientific basis for developing sustainable air quality management strategies in industrial megacities.

Keywords

Main Subjects

با رشد فزاینده شهرنشینی و توسعه صنعتی، کلان‌شهرهای ایران با چالش‌های جدی ناشی از آلودگی هوا مواجه‌اند و اصفهان به‌عنوان یکی از قطب‌های صنعتی کشور در سال‌های اخیر شرایط بحرانی‌تری را تجربه کرده است.

هدف پژوهش حاضر، تحلیل فضایی ـ زمانی آلاینده‌های اصلی هوا در کلان‌شهر اصفهان طی دوره ۱۳۹۷ تا ۱۴۰۲ با استفاده از داده‌های ماهواره‌ای Sentinel-5P (سنجنده (TROPOMI) و داده‌های ایستگاه‌های سنجش زمینی است. در این مطالعه، توزیع مکانی و روند زمانی پنج آلاینده شامل دی‌اکسید نیتروژن (NO₂)، مونوکسید کربن (CO)، دی‌اکسید گوگرد (SO₂)، ذرات معلق کوچک‌تر از ۲.۵ میکرون (PM₂.₅) و شاخص UV Aerosol Index (UVAI) مورد بررسی قرار گرفت، به‌طوری‌که داده‌های آلاینده‌ها از ایستگاه‌های زمینی پایش کیفیت هوا و تصاویر ماهواره‌ای گردآوری شد. برای تحلیل و تلفیق داده‌ها از روش‌های درونیابی مکانی استفاده گردید و در ادامه به‌منظور بررسی روابط مکانی و الگوهای توزیع آلاینده‌ها از مدل‌های رگرسیون خطی معمولی (OLS) و رگرسیون وزنی جغرافیایی (GWR) بهره گرفته شد.

نتایج نشان داد که، آلاینده‌های NO₂ و CO بیشترین تمرکز را در مناطق مرکزی و شمالی شهر داشته و از مرکز به سمت شرق و جنوب کاهش یافته‌اند. غلظت SO₂ پراکنشی نوسانی و متغیر در سال‌های مختلف داشته، در حالی که مقادیر UVAI عمدتاً در شرق و شمال‌شرق شهر بالاتر بوده است. همچنین PM2.5 در مناطق مرکزی و شمالی در سطوح بالاتری مشاهده شد. تحلیل روند زمانی نشان داد که در سال ۱۳۹۹ همزمان با اعمال محدودیت‌های کرونایی، کاهش معناداری در مقادیر آلاینده‌های NO₂، CO، PM2.5  و UVAI رخ داد، اما از سال ۱۴۰۰ به بعد غلظت‌ها مجدداً افزایش یافته و به سطح پیش از همه‌گیری بازگشتند. همچنین این یافته‌ها نشان می‌دهد که، منابع انسان‌ساخت، به‌ویژه ترافیک و فعالیت‌های صنعتی، نقش اصلی در شکل‌گیری الگوهای آلودگی هوای اصفهان دارند. بهره‌گیری از داده‌های ترکیبی ماهواره‌ای و زمینی می‌تواند مبنای مناسبی برای سیاست‌گذاری محیط‌زیستی و برنامه‌ریزی جهت مدیریت پایدار کیفیت هوا در این کلان‌شهر فراهم آورد.

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Remote Sensing and GIS Applications in Environmental Sciences
Volume 6, Issue 19
July 2026
  • Receive Date: 02 September 2025
  • Revise Date: 06 December 2025
  • Accept Date: 29 January 2026