The study of effects of greenery on temperature reduction in urban areas

Abstract

Urban landscape is largely characterized by high degree of built space, high share of artificial surface material and the reduction of green areas, which leads to changes in the microclimate and the deterioration of thermal comfort in outdoor urban space. One of the most important roles of urban greenery is the impact on the reduction of air temperature due to less heating of green space compared to paved surfaces and due to tree shading. The paper analyses the influence of urban greenery on temperature reduction. Aim of the study was to measure the difference in warming up of grassy surfaces and paving materials commonly used for public areas and to evaluate the impact of tree shading on the surface cooling during the day. For this purpose, measuring of surface temperatures was performed during the summer months in 2015 in the central city zone of the city of Nis. The measuring included: grass, asphalt as most commonly used paving material, and concrete tiles commonly used for pedestrian areas. Results show the temperature of grass is significantly lower than the temperature of paved surface at any time of day. In the case of paved surfaces, temperature of shaded or partially shaded material is lower than the temperature of surface exposed to sunlight during the whole day, a temperature difference exists even after nocturnal cooling. The results indicate the importance of green areas for cooling of urban spaces, due to their lower warming and surface shading from tree canopy. IntroductionUrban environment is defined as the physical environment in urban areas, with its complex mix of natural elements (including air, water, land, climate, flora and fauna) and the built environment, i. e. a physical environment constructed or modified for human habitation and activity encompassing buildings, infrastructure and urban open spaces [1]. The process of urbanization brought about changes in cityscape, reduction of green areas and increase of paved areas, and the changes of city climate and emergence of so called urban heat islands (UHI). The UHI represent the areas inside cities where the air temperature is higher than the air temperature of the surrounding area. With higher temperatures, energy consumption in-_______________ Djekić, J. P., et al.: The Study of Effects of Greenery on Temperature Reduction …

Predicting changes in land use/land cover and seasonal land surface temperature using multi-temporal landsat images in the northwest region of Bangladesh

“…Massive infrastructural development increases the proportion of impervious and paved surfaces, which retained more energy and radiated more heat [ 65 , 66 ]. On the other hand, green space consists of penetrable layers and emitted less heat due to tree shading, which helps to reduce the heat [ 67 ].…”

Micrometeorological and Hydraulic Properties of an Urban Green Space on a Warm Summer Day in a Mediterranean City (Attica–Greece)

“…According to the results of the study of Ðekić et al [72], a distinct variation between the temperatures of various surfaces in UGSs was identified, particularly in the high solar radiation hours-around noon. More specifically, they found that the temperature difference between the grass surface (coolest) and the dark asphalt varied between 9 and 19.7 • C, whereas in our study it was on average 16.3 • C. In addition, Ðekić et al [72] also observed a difference of 10-24.5 • C between the hottest surface temperature and that of the ambient air, a range that is in line with the findings of our study where the respective difference between the asphalt and the ambient air temperature, measured by the meteorological station, was 18.2 • C. Similarly, Ðekić et al [72] mention that for the hotter period of measurements (mid-July to mid-August) the average maximum temperature for all artificial surfaces was well above 50 • C (average 52.1 • C in our study for all artificial materials ranging from 49.6 • C for the internal paved corridors to 54.4 • C for asphalt), while the grass-covered area more or less matched the temperature of the ambient environment, which is also in line with our study, since the temperature differences of grass and shrubs against ambient air temperature measured by our station were very close (38.0-35.8 • C and 36.7-36.1 • C, respectively.…”

Design Study Co-Working Space Building Based On Bioclimatic Architectural Principles

“…C. Relation to landscape Landscapes or green areas can make buildings cooler and also the aesthetic purposes (Diana et al, 2021). Vegetation affects room temperature regulation because it has a cooling (Dekić et al, 2018). The shade from the tree helps lower temperatures and reduces energy use (Dekić et al, 2018).…”

“…Vegetation affects room temperature regulation because it has a cooling (Dekić et al, 2018). The shade from the tree helps lower temperatures and reduces energy use (Dekić et al, 2018). Based on figure 3.5, landscape area of this building has less green area.…”