The Effects of Elevation on Thermal Bioclimatic Conditions in Uludağ (Turkey)

Onur Çalışkan, Necla Türkoğlu, Andreas Matzarakis


This study compares the thermal bioclimatic conditions recorded at Bursa (100 m) and Uludağ (1878 m) meteorological stations at 7:00, 14:00 and 21:00 LST (local standard time) between 1975 and 2006, by using the physiologically equivalent temperature (PET), which is calculated from meteorological parameters. The effects of elevation-dependent environmental and atmospheric conditions on thermal perception (i.e., PET) values were analyzed and assessed. The analysis showed that the mean annual difference between PET values in Bursa and Uludağ was 12 ºC. The difference was lower in winter (9 ºC PET) and higher in summer (15 ºC PET). The highest difference between PET values occurred in the afternoon (16 ºC PET) and the lowest difference occurred in the morning (8.4 ºC PET). The differences occur as a result of high altitude and higher surface albedo due to snowfall, which leads to lower PET values and thus to less comfortable thermal conditions. The mean PET values of Bursa and Uludağ decrease 0.67 ºC every 100 m.


Thermal comfort; bioclimatic conditions; vertical gradient; physiologically equivalent temperature; Turkey

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