Assessing the cooling effects of built-up areas for mitigating thermal discomfort in semi-arid urban environments: a case study of Tehran

IF 2.8 3区地球科学 Q2 ASTRONOMY & ASTROPHYSICS

Advances in Space Research Pub Date : 2026-03-15 Epub Date: 2026-01-12 DOI:10.1016/j.asr.2026.01.025

Firouz Aghazadeh , Akbar Rahimi , Mohammad Karimi Firozjaei , Vladimir Ondrejicka , Maros Finka

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引用次数: 0

Abstract

Urbanization has significantly transformed land-use patterns and continues to influence thermal comfort in cities. This study explores how built-up areas contribute to reducing thermal discomfort in semi-arid regions, focusing on Tehran from 2000 to 2024. Landsat 7 and 8 satellite data were used to classify land use, derive Land Surface Temperature (LST), and assess thermal stress through the Discomfort Index (DI). To evaluate cooling performance, several indicators were applied, including Temperature and Discomfort Index variations for both Urban Green Spaces (UGS) and built-up areas (Temperature Urban Green Space (TUGS), Temperature Built-up (TBU), Discomfort Index Urban Green Space (DIUGS), and Discomfort Index Built-up (DIBU)), as well as Apparent Temperature differences (Apparent Temperature Urban Green Space (ATUGS), and Apparent Temperature Built-up (ATBU)). During the study period, built-up areas expanded from 55% to 68%, while UGS coverage peaked at 18% in 2014 before declining to 14% in 2024. Despite their ecological importance, green spaces showed only a slight cooling influence, with mean LST decreasing by just −0.13°C. However, DI dropped more noticeably (−0.51°C), indicating the importance of humidity in shaping thermal comfort. Meanwhile, UGS temperatures increased from 36.0°C to 38.7°C, whereas built-up zones experienced a minor cooling trend. Cooling indices revealed a gradual loss of cooling benefits from UGS and an enhanced moderating effect from built-up structures. TUGS decreased from 2.92 to −0.40, while TBU increased from 1.09 to 2.56. Similarly, ATUGS weakened from −3.54 to 0.36, whereas ATBU improved from −1.09 to −2.77. Correlation analysis showed that larger UGS patches still offer better cooling, although patch complexity has limited impact. Overall, the findings underscore growing urban heat pressure in Tehran and the weakening role of green spaces in temperature regulation. At the same time, they highlight the emerging significance of built-up morphology and shading features in improving thermal comfort across a rapidly urbanizing landscape.

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评估建成区在半干旱城市环境中缓解热不适的冷却效果：德黑兰的案例研究

城市化极大地改变了土地利用模式，并继续影响着城市的热舒适。本研究探讨了建成区如何有助于减少半干旱地区的热不适，重点是2000年至2024年的德黑兰。利用Landsat 7和8卫星数据对土地利用进行分类，得出地表温度（LST），并通过不适指数（DI）评估热应力。为了评估降温效果，采用了几个指标，包括城市绿地（UGS）和建成区的温度和不适指数变化（城市绿地温度（TUGS）、建筑温度（TBU）、城市绿地不适指数（DIUGS）和建筑不适指数（DIBU）），以及视温差（城市绿地表观温度（ATUGS）和建筑表观温度（ATBU））。在研究期间，建成区面积从55%扩大到68%，而UGS覆盖率在2014年达到18%的峰值，然后在2024年下降到14%。尽管具有重要的生态意义，但绿地仅表现出轻微的降温影响，平均地表温度仅下降- 0.13°C。然而，DI下降更为明显（- 0.51°C），表明湿度在塑造热舒适方面的重要性。与此同时，UGS温度从36.0°C上升到38.7°C，而建成区则有轻微的降温趋势。冷却指数显示，UGS的冷却效益逐渐丧失，而建筑结构的调节作用增强。TUGS从2.92下降到- 0.40，TBU从1.09上升到2.56。同样，ATUGS从−3.54下降到0.36，而ATBU从−1.09上升到−2.77。相关分析表明，较大的UGS补丁仍然提供更好的冷却效果，尽管补丁复杂性的影响有限。总的来说，研究结果强调了德黑兰日益增长的城市热压力和绿地在温度调节中的作用减弱。同时，他们强调了在快速城市化的景观中，建筑形态和遮阳特征在改善热舒适方面的新兴意义。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Advances in Space Research 地学天文-地球科学综合

CiteScore

5.20

自引率

11.50%

发文量

800

审稿时长

5.8 months

期刊介绍： The COSPAR publication Advances in Space Research (ASR) is an open journal covering all areas of space research including: space studies of the Earth''s surface, meteorology, climate, the Earth-Moon system, planets and small bodies of the solar system, upper atmospheres, ionospheres and magnetospheres of the Earth and planets including reference atmospheres, space plasmas in the solar system, astrophysics from space, materials sciences in space, fundamental physics in space, space debris, space weather, Earth observations of space phenomena, etc. NB: Please note that manuscripts related to life sciences as related to space are no more accepted for submission to Advances in Space Research. Such manuscripts should now be submitted to the new COSPAR Journal Life Sciences in Space Research (LSSR). All submissions are reviewed by two scientists in the field. COSPAR is an interdisciplinary scientific organization concerned with the progress of space research on an international scale. Operating under the rules of ICSU, COSPAR ignores political considerations and considers all questions solely from the scientific viewpoint.