Izvorni znanstveni članak
Surface urban heat island in Varaždin
Igor Žiberna
orcid.org/0000-0003-4796-4061
; Filozofski fakultet, Sveučilište u Mariboru, Slovenija
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* Dopisni autor.
Sažetak
Urban ecosystems today represent the dominant environment for the majority of the world‘s population. Urban ecosystems are characterized by predominantly anthropogenic energy sources and higher energy density. The result is an anthropogenically altered “metabolism”, which is the result of changed land use and artificial energy sources created by human activity. This is also reflected in cities in changed local climatic characteristics, and most notably in the formation of the urban heat island. The formation of the urban heat island in conditions of global warming causes additional heat stress for the inhabitants of these cities, which reduces the quality of the living environment. Case studies of urban heat islands can thus show us hot spots in cities and can represent the basis for planning to mitigate the consequences of local and global climate change with the aim of improving or at least maintaining the quality of the living environment. The settlement of Varaždin had a population of 36187 in 2021. This ranked Varaždin in 10th place among settlements in the Republic of Croatia. In our case, we analyzed surface temperatures in the wider Varaždin area. To analyze the surface urban heat island, we used the remote sensing method, namely images from the Landsat 8 satellite in the 10th and 11th channels, which record radiation in the infrared part of the spectrum. In the analysis, we used 22 satellite images for days when the weather was completely clear over Varaždin. The images used cover the time window between 2019 and 2024. The images are evenly distributed across the climatic seasons (five images each in winter, spring, summer and autumn). The average annual temperatures of the surface urban heat island in the Varaždin area fluctuate between 11,1 °C and 24,1 °C. The warmest pixel in the area under consideration is not located in the old city centre, but in the area of the Lumini shopping centre in the south-eastern part. Other areas with the highest surface temperatures are also located in areas of trade and service activities. The area of the shopping centre north of Gospodarska ulica stands out, the area of the Varteks S-Park complex west of Zagrebačka ulica, the area of the Supernova Varaždin shopping centre south of Optujska ulica and the Varaždin metal industry complex. The lowest surface temperatures occur in the area of Varaždin Lake, and within the built-up area, the southern part of the buildings of the Comet d.o.o. company, park areas (Stari grad, the park east of Ulica Ratimir Hercega together with the city cemetery, Šetalište Vatroslava Jagića) and some green areas consisting of fields and meadows and which in the eastern and northern parts of Varaždin extend into the denser built-up area in the form of piers. The surface urban heat island in the area under consideration shows a pronounced seasonal regime. It is most developed and structured in summer, and least in winter. In spring, the heat island is more structured, although in autumn the surface temperatures are generally higher than in spring, as the city is still overheated from summer. We can also conclude that due to the appropriate approach to urban development of Varaždin, there are still some green areas left in the city, which significantly mitigate excessive overheating, especially in the summer months. The water surface of Varaždin Lake also reduces heat loads in the summer months. When planning possible future shopping centers in Varaždin and its outskirts, it would be a good idea to consider the use of light surfaces on roofs and parking areas and the use of as many green areas as possible in the form of trees, which would shade the surroundings with their canopies and mitigate overheating due to the increased consumption of latent energy during transpiration.
Ključne riječi
urban climate; surface urban heat island; heat load; Varaždin
Hrčak ID:
350980
URI
Datum izdavanja:
25.6.2026.
Posjeta: 0 *