According to the measurements of the urban climate research group of the University of Szeged, urban green areas can significantly reduce the heat load and improve the comfort of the people who live there – the public relations directorate of the higher education institution informed MTI.
According to the announcement, the group examines the precise spatial and temporal characteristics of urban heat island intensity, measures the role of built-up areas in the strengthening of the process, and also provides a forecast of the phenomenon.
The heat load on the human body is quantified using the Physiologically Equivalent Temperature (PET) index. The meter simultaneously takes into account the air temperature, wind speed, level of air humidity, and the amount of energy from solar radiation, as these four factors together affect the feeling of heat, so it is more “eloquent” than a simple air temperature data.
If the body is subjected to very high heat stress, even in the case of a healthy person, the heat balance can quickly be upset, which can have serious health consequences, such as heat stroke. This is even more critical in the case of people who are sensitive to it, such as small children, the elderly, and people with cardiovascular disease.
Since the 2010s, Szeged researchers have continuously and comprehensively collected data on how mosaic a settlement’s heat stress map can be. Where there is no green space, the PET index value of heat load can be even 10-15 degrees higher in the summer heatwave, and the difference in surface temperature can be even greater. In addition, the energy “harvested” by buildings and paved surfaces during the day is radiated as heat at night, so in the inner cities, there is no relief for the environment or the human body, while in a suburban, greener area, the night brings relief.
It is therefore important that city planners take this into account and create public spaces that can mitigate heat stress as effectively as possible. The most obvious means of this are green and water surfaces, the former – especially trees – can significantly improve the microclimate through shading, and the latter through evaporation.