Original scientific paper
Surface Urban Heat Island in Ptuj
Igor Žiberna
orcid.org/0000-0003-4796-4061
; Faculty of Arts, University of Maribor, Maribor, Slovenia
*
* Corresponding author.
Abstract
Urban areas today represent the dominant ecosystem for humanity, as 55% of the world‘s population lives in cities. Projections show that this share could increase to 68% by the middle of the 21st century. It has been proven that every clustered settlement with over 1000 inhabitants already forms a recognizable heat island. At the beginning of 2024, 56,8% of the population lived in 240 settlements with over 1000 inhabitants in Slovenia. A good half of the population of Slovenia is therefore in one way or another under the influence of higher temperatures due to heating of the air in settlements. The heat load in settlements is also further fueled by positive trends due to global warming. Studying urban ecosystems is therefore important in these circumstances if we want to maintain the quality of the living environment in cities.
The settlement of Ptuj is one of the larger Slovenian settlements in terms of population. With 23872 inhabitants, it ranked 8th among 6039 Slovenian settlements in 2024. The settlement of Ptuj is ranked 59th in terms of area and 11th in terms of population density. It is therefore a settlement that is already large enough for anthropogenic influences on changing the local climate to be reflected in the formation of an urban heat island.
The surface urban heat island in Ptuj is closely related to land use, especially the level of building. In Ptuj, the highest surface temperatures are found on closed, densely built-up areas with an impermeability level of over 80% and on industrial and commercial areas. These areas are east and south of the Pragersko-Ormož railway line in the area where shopping centres and manufacturing and service activities are currently located in the eastern part of Ptuj. Higher temperatures also occur in the area of the old town centre between Grajski grič and the Drava river, and in the stretch between the General Hospital of dr. Jože Potrč - the Ptuj School Centre - the shopping centre with parking lots along Volkmerjeva cesta. The surface heat island is the largest and most intense in the summer, when smaller heat islands merge into one in the area of trade, service and manufacturing activities in the south-eastern part of Ptuj.
The surface urban heat island is more intense in autumn than in spring, and is least developed in winter, which is partly due to the influence of snow cover, which homogenizes the physical properties of the surface (albedo, specific heat, thermal conductivity, etc.). When planning the future spatial development of Ptuj, more attention will need to be paid to green and water areas in the more densely built-up parts of the city. One solution could be to introduce smaller tree-lined avenues along newly created streets, which would change the energy balance due to transpiration and shading of the surface. It might also be a good idea to consider arranging newly planned parking lots. These could be covered with appropriately shaped paving stones that would allow for the growth of short grass. Of course, this is associated with additional maintenance costs and more difficult plowing in winter. However, it will be necessary to internalize the fact that the expansion of built-up areas in cities, coupled with the global warming trend, increases heat loads in cities, which lowers the quality of the living environment, and at the same time affects vulnerable groups of people (children, elderly residents, patients, socially isolated groups of the population) the most. Changes in local and global climate will have to become a new important element and criterion in spatial planning of settlements.
Keywords
urban climate; surface urban heat island; heat load; Ptuj
Hrčak ID:
334425
URI
Publication date:
31.7.2025.
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