Thermal comfort in urban microclimate areas and future-oriented climatic modeling: The case of Diyarbakır city center

Urbanization and escalating global warming are significant issues of the last century and the forthcoming century. The phenomenon of urban heat islands, which are a consequence of unregulated development and high-density construction, particularly in large cities, have a significant impact on human thermal comfort. This study focuses on four central districts in Diyarbakır city center, which has a hot and dry climate in summer and a cool and humid climate in winter. Four different areas representing the traditional architectural structure of the region (Sur), traditional and modern structure (Yenişehir), modern structure (Kayapınar), and unplanned urban structure (Bağlar) were considered. Simultaneously, this study utilised three decades of climate data procured from stations under the administration of the Turkish Meteorological General Directorate, complemented by on-site meteorological measurements. In four distinct study areas, four different scenarios were analysed across two seasons. The first scenario comprised 20% grass, the second scenario 80% grass, the third scenario coniferous plants, and the fourth scenario deciduous plants.In the course of the study, scenarios were created using ENVI-met software with existing data. The validity of the present scenarios was ascertained by means of Landsat 8 satellite surface temperature analysis and on-site measurements. In future scenarios, the SARIMAX model, which operates on a machine learning infrastructure, was employed to predict the climate variables of the study areas for the year 2050. The scenarios of the predicted climate variables were evaluated with ENVI-met software, and the results were obtained. The findings, based on the available data (2022), indicate that scenario 4, with a 41.8 °C PET value, yielded the optimal outcome in the summer months within the urban and modern structure. Additionally, scenario 3, with a 46.3 °C PET result, demonstrated its efficacy in the modern structure. The current scenario also exhibited a 44.3 °C PET value in the urban structure and scenario 4, with a 47.6 °C PET value, in the traditional structure. With regard to the scenarios for the winter months, although similar results were obtained in all scenarios in the study area of traditional and modern structures, Scenario 4 provided the most comfortable environment with an PET value of 29.5 °C in the Bağlar district, especially in the distorted structure. In the future summer scenarios, scenario 4 demonstrated the highest performance with an PET value of 47°C in the Yenişehir district, which exhibits a combination of modern and traditional structures. Conversely, scenario 4 exhibited the most comfortable values with PET values of 49.2°C in modern texture, 46.2°C in skewed urban texture, and 38.3°C in traditional structure, respectively. In the context of the winter season, Scenarios 1 and 2 resulted in the creation of more comfortable areas across all study areas. The findings of this study will provide a foundation for local and administrative administrations, particularly at the urban scale. Keywords: Thermal comfort,Diyarbakir, ENVI-met, SARIMAX