The effect of built environment parameters on microclimate and outdoor thermal comfort in different urban textures: The case of Konya city

Due to the increased greenhouse gas emissions as a result of intensive industrialization and urbanization, temperatures increase in urban centers and differences occur compared to rural areas. This is known as the urban heat island effect. The urban heat island effect causes many negative conditions in cities, the most important of which is uncomfortable outdoor environments, resulting in health problems. Due to its many negative consequences, the urban heat island effect has been tried to be reduced especially in recent years and many strategies have been developed. Chief among these are increasing urban vegetation and raising albedo. The urban heat island effect can be affected by many conditions such as population density, urban morphology, thermal properties of urban surface materials, vegetation density in urban areas, anthropogenic heat release, evapotranspiration, wind speed, cloud cover and urban energy balance. For this reason, it also shows differences in regions with different characteristics within the city center. These differences also affect the users within the city in different dimensions. In this study, it is aimed to determine the effect of urban heat island effect on outdoor thermal comfort in summer and winter seasons for different areas in 6 different local climate zones (LCZ) in Konya city with BSk (cold-semi-arid) climate and to find the most thermally comfortable areas in the city. For the analyses, the dates of July 10, a typical summer day, and January 10, a typical winter day, were determined and 10-year (2012-2021) hourly air temperature, wind speed and relative humidity values of these dates were obtained from "Konya Regional Station". Analyses were carried out using ENVI-met simulation program with the average hourly data. Using the obtained climate parameters (Ta, Ws, RH, MRT) and the BIO-met module in the same simulation program, PET (Physiological equivalent temperature) values, which is a thermal comfort index, were found as average for summer and winter seasons. These values were used by calculating the average of 10 different points within the whole local climate zone. With the findings obtained, the general relationships between the parameters were questioned, changes in climate parameters during the day were observed, maximum, minimum and average values were determined. Comparisons between the reference meteorological station (RMI) and different local climate zones were evaluated. In other stages, the urban heat island effect and outdoor thermal comfort levels were determined in all local climate zones, and the relationships between them and built environment parameters were questioned. Finally, points with different characteristics within a local climate zone were compared. According to the results, it was found that there were strong correlations between SVF-PET and SVF-MRT for the summer season, while no correlation was found in the winter season. All climate parameters were found to vary continuously in summer and winter at different points within the local climate zone and at different time intervals. As a result of the comparisons with the reference meteorological station, the existence of the urban heat island effect for summer and winter seasons in all 6 different local climate zones located in the city center is determined. In summer and winter seasons, this effect is highest in LCZ-1 and lowest in LCZ-6. As a result of outdoor thermal comfort analysis, it was observed that the most comfortable zone in summer was LCZ-1 and the least comfortable zone was LCZ-4. In winter season, the most comfortable zone is LCZ-3 and the least comfortable zone is LCZ-4. Among the built environment parameters, total plan area to total area ratio, total building volume and building surface area are found to be strongly related to the urban heat island effect and outdoor thermal comfort in summer and winter seasons. Among the built environment parameters, h/W ratio and building floor area ratio were not found to be correlated for both seasons.