Geographia Polonica Vol. 90 No. 4 (2017)

The article presents the evolution of water temperature changes in the Wisłok river (the upper Vistula basin) as an effect of Besko reservoir, existing since 1978, with a capacity of 15 million m3 . The thermal effect of this small Carpathian reservoir is compared to that of larger reservoirs located in the region. As has been found in the analysis, the direction (increase or decrease) of the annual water temperature variations in the Wisłok as a consequence of the thermal conditions in the reservoir is the same as in other Carpathian rivers downstream of larger reservoirs. On the other hand, the scale of that effect is much smaller and it is observable in a shorter section of the river compared to other rivers with reservoirs. Therefore, the thermal effects of Besko reservoir may be considered of little significance for the natural environment.

24 cm