Choiński, AdamŁawniczak, AgnieszkaPtak, Mariusz2018-07-042018-07-042013Badania Fizjograficzne, Seria A, Tom 64, 2013, s. 39-49978-83-7654-221-82081-6014http://hdl.handle.net/10593/23614This study presents the characteristics of ice phenomena occurring on selected lakes in the Wielkopolski National Park based on long-term observations of Góreckie Lake (1971–1992) and fieldwork performed in February 2012 on six other water bodies. The investigation revealed the advancement of ice phenomena appearance within the space of twenty years, as well as the advancement of their disappearance. Such a situation also concerned the ice cover. In turn, the analysis of maximum ice thickness showed an incre- asing trend, while the number of days with compact ice cover decreased. No direct relationship was observed between the rise in average annual water temperature and the delay in the appearance of ice phenomena in a subsequent year. Variation in ice cover thickness measured on the six lakes studied in February 2012 was low and amounted to only 5.5 cm. The thickest (35 cm) and the thinnest (29.5 cm) ice was recorded on the same water body. Fieldwork showed that ice cover thickness was mostly determined by climatic conditions and not influenced by the individual features of the consecutive lakes.polinfo:eu-repo/semantics/openAccessice phenomenalakesWielkopolski National ParkArtykułhttps://doi.org/10.2478/bfpz-2013-0003