Abstract
Urban heat islands (UHI) and rapid urbanisation create new health risks for residents of urban territories. The authors consider lawns as an eco-stabilising factor of the urban environment and an element of ensuring the environmental safety of the capital. The purpose of this study was to determine the qualitative state of lawns to the factors of the urban ecosystem and their thermoregulatory function. To determine the impact of anthropogenic factors on research objects, the study assessed the amount of emissions into the atmospheric air from stationary and mobile sources, satellite maps of the intensity of nitrogen dioxide emissions (NO2 ) and sulphur dioxide (SO2 ) in the city’s air basin, heat distribution, and normalised difference moisture index (NDMI). To assess the condition and quality of lawns, the methods of assessing the grasslands of A.A. Laptev (1983) and an unmanned aerial vehicle (UAV) were used. It was established that the results of the evaluation of lawn coenoses using the method of O.O. Laptev and UAV are correlated (r=0.87). Lawn areas that were rated as in “satisfactory condition” are characterised by a higher temperature on the heat map and lower NDMI values. Indicators of lawn cover that were rated as in “good condition” correlate with surface temperature and NDMI. The difference in surface temperatures over the area of the experimental sites reaches 5°C and depends on the objects surrounding the perimeter. It was established that lawn areas adjust the thermal mode of the urban system in the warm period of the year, and reduce the temperature of the asphalt surface by about 0.5°C, and together with flower and woody plants – by about 0.9°C. The study results improve the understanding of the physiological effects of heat stress on lawn areas, which allows developing practical strategies for managing urban green spaces with limited water resources and anthropogenic loads