ABSTRACT
The objective of this study was to analyze air pollution and thermal environment in Turkey's cold region before, during, and after COVID-19 in 2019, 2020 and 2021. The CO, NO2, O3, PM10 and SO2 data from the state air quality stations, as well as ground air temperature data from six weather stations, and land satellite images from the USGS website using ArcGIS 10.4.1 software were collected in January, March, April and August of 2019, 2020 an 2021. In order to evaluate the impact of COVID-19 measures and restrictions on cold region cities, air pollution indicators, land surface temperature and air temperature as well as statistical data were analyzed. The results indicated that the CO, NO2, PM10 and SO2 emissions decreased by 14.9%, 14.3%, 47.1% and 28.5%, but O3 increased by 16.9%, respectively, during the COVID-19 lockdown in 2020 as compared to these of the pre-COVID-19 levels in 2019. A positive correlation between air temperature and O3 in 2019 (r2 = 0.80), and in 2020 and 2021 (r2 = 0.64) was obtained. Air temperature in 2020 and 2021 decreased due to lockdowns and quarantine measures that led to lower O3 emissions as compared to 2019. Negative correlations were also found between air temperature and NO2 (r2 = 0.60) and SO2 (r2 = 0.5). There was no correlation between air temperature and PM10. During the COVID-19 lockdown and intense restrictions in April 2020, the average LST and air temperature values dropped by 14.7 °C and 1.6 °C respectively, compared to April 2019. These findings may be beneficial for future urban planning, particularly in cold regions.
ABSTRACT
Currently, cities are at the center of the debate on global warming since land use and land cover change (LULC) in cities are considered to be major contributors to global climate change. In this study, Çarsi and Dogukent Neighborhood areas in the city center of Elazig province, Turkey, were examined in terms of land use and land cover (LULC). Both areas were chosen because they have different patterns and features, such as different residential densities, street aspect ratios and orientations, impervious surfaces, vegetation, and elevations. The aim is to assess the effect of the different patterns of these settlements on the land surface temperature (LST) using Landsat 8 satellite images in the summertime, July 19, 2021. The results showed that the maximum, minimum, and average LST of the Dogukent Neighborhood, which is characterized by uniform streets with dense vegetation and streets oriented to the NE-SW or NW-SE, were recorded as 44.4, 38.4, and 41.0 °C, respectively, while 45.4, 40.4, and 43.8 °C were recorded in the Çarsi Neighborhood characterized by excessive residential areas and deep streets with lack of vegetation oriented to the E-W direction. However, the average difference is around 2.8 °C, implying that residential areas with mid-building heights and vegetated streets oriented to NE-SW or NW-SE are thermally better than those with high aspect ratio streets and lacking vegetation and oriented to E-W. It was found that small variations in land elevation of these areas do not significantly affect the LST. The results of this study will set an example not only for the city of Elazig, but also for the determination of urban transformation areas, new housing areas, and climate change in most cities of Turkey and other countries, and will provide support for sustainable and more livable urbanization in most cities. Transferring the data obtained by local governments to the physical plan decisions could also contribute to preventing climate change.
