Analysis of outdoor thermal comfort and air pollution under the influence of urban morphology in cold-climate cities: Erzurum/Turkey

The increase in population in urban areas has increased the demand for housing. In cities that could not adapt to the population increase, the attempt to fit more houses in a unit area has emerged. This situation caused the application of created designs ignoring the natural and microclimate data of the cities. Since Erzurum is located on the high plain surrounded by mountains, it is one of the coldest cities in Turkey with its long-term annual mean temperature of 5.7 degrees C. The aim of this research is to reveal the effects of the urban morphology on thermal comfort and its relationship with air pollution in Erzurum. Steps of the research methodology can be summarized as determination of measurement areas, physiologically equivalent temperature (PET) analysis, air pollution analysis, and mapping. The city center is located at an altitude of 1850 m from the sea level, and the open rural area has the lowest altitude of 1650 m from the sea level with respect to the surrounding mountainous terrain. The microclimate data of the meteorological stations in the three study areas and government monitoring station and air pollution data have been recorded hourly in 2018. The recorded data was analyzed with the RayMan pro 2.1 model, which is a widely used simple index PET for obtaining outdoor thermal comfort. According to the research results, the highest PET value of Erzurum was obtained in the city center as 11.4 degrees C and then the urban transformation district as 6.3 degrees C, and the lowest PET was obtained from the open rural area as 4.5 degrees C. In the areas that have low PET values and cold stress issues, it was observed that the air pollution data are low. The city center was detected to have the highest air pollution parameters. It was determined that urban morphology, air pollution, and thermal comfort had significant correlations.