MICROCLIMATE-BASED EVALUATION OF OUTDOOR THERMAL COMFORT IN COLD CLIMATE REGIONS: The Case of Hilalkent TOKİ

Öz

This study comparatively evaluates the existing and five different urban design scenarios developed for the Hilalkent TOKİ housing area in Erzurum, using ENVI-met simulations for both summer and winter periods. Outdoor thermal comfort was analyzed primarily through Physiological Equivalent Temperature (PET), along with air temperature, wind speed, and relative humidity parameters. The summer simulation results revealed pronounced differences among the scenarios, highlighting tree density as a key determinant of thermal comfort. The scenario incorporating a 30% increase in tree coverage produced the lowest PET values due to enhanced shading and evapotranspiration effects, thereby significantly reducing heat stress. In contrast, scenarios including water surfaces, bare soil, and green roof applications provided only limited improvements in thermal comfort during the summer period. During the winter period, all scenarios were characterized by cold stress conditions resulting from low air temperatures. Scenarios incorporating water surfaces exhibited adverse effects in winter due to increased relative humidity levels. When both summer and winter periods were evaluated together, the scenario with a 30% vegetation increase emerged as balanced and sustainable option, offering improved outdoor thermal comfort conditions throughout the year. The findings of this study indicate that urban design strategies in cold-climate cities should be developed based on season-sensitive, tree-oriented, and microclimate-based approaches.

Anahtar Kelimeler

• ENVI-met 5.6.1
• vegetation
• residential garden
• Physiologically Equivalent Temperature (PET)

SOĞUK İKLİM BÖLGELERİNDE DIŞ MEKÂN TERMAL KONFORUNUN MİKROİKLİM TABANLI DEĞERLENDİRİLMESİ: Hilalkent TOKİ örneği

Öz

Bu çalışmada, Erzurum Hilalkent TOKİ yerleşim alanı için geliştirilen bir mevcut beş farklı kentsel tasarım senaryosu, ENVI-met simülasyonları kullanılarak yaz ve kış dönemleri için karşılaştırmalı olarak değerlendirilmiştir. Dış mekân termal konforu; Fizyolojik Eşdeğer Sıcaklık (PET) başta olmak üzere hava sıcaklığı, rüzgâr hızı ve bağıl nem parametreleri üzerinden analiz edilmiştir. Yaz dönemi sonuçları, senaryolar arasındaki farkların belirginleştiğini ve özellikle ağaç yoğunluğunun termal konfor üzerinde belirleyici bir rol oynadığını göstermiştir. %30 ağaç artışı içeren senaryo, gölgeleme ve evapotranspirasyon etkileri sayesinde en düşük PET değerlerini üretmiş ve ısı stresini anlamlı biçimde azaltmıştır. Buna karşılık, su yüzeyi, toprak zemin ve yeşil çatı uygulamaları yaz döneminde sınırlı iyileşme sağlamıştır. Kış döneminde ise tüm senaryolarda düşük hava sıcaklıklarına bağlı olarak soğuk stres koşullarının hâkim olduğu belirlenmiştir. Su yüzeyi içeren senaryolar, artan bağıl nem nedeniyle kış döneminde olumsuz bir etki göstermiştir. Yaz ve kış dönemleri birlikte değerlendirildiğinde, %30 bitki oranına sahip senaryo, yıl boyu dengeli ve sürdürülebilir dış mekân termal konfor koşullarını sunan senaryo olarak öne çıkmıştır. Çalışma sonuçları, soğuk iklim kentlerinde kentsel tasarım kararlarının mevsime duyarlı, ağaçlandırma ağırlıklı ve mikro iklim temelli yaklaşımlar doğrultusunda ele alınması gerektiğini ortaya koymaktadır.

Anahtar Kelimeler

• ENVI-met 5.6.1
• vejetasyon
• toplu konut bahçesi
• Fizyolojik Eşdeğer Sıcaklık (FES)

Kaynakça

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