The aim of the study was to identify patterns of ice-related phenomena on 39 selected anthropogenic water bodies in the Silesian Upland in southern Poland. The core research was conducted in the winter season of 2009/2010, between December and March. Field measurements and observations were conducted every two days during the freezing and thawing phases and every four days at the time of continuous ice cover. Data were interpolated to cover days without observations. Differences in the ice cover phenology on these water bodies were caused by natural conditions (morphometric and hydro-meteorological) and human activity (thermal pollution). Two principal groups of anthropogenic water bodies were identified in terms of the ice phenomena: lakes and ponds with a natural or quasi-natural pattern of ice phenomena and water bodies featuring various degrees of human impact. The thickness of the ice-cover was found to vary, which was a source of great danger to the users of the water bodies in the winter season.

The traditions related to mining activities in the Silesia-Cracow area go back to the 11 th century when lead, silver, and iron ores were exploited from open pit mines. For centuries, the growth in ore exploitation was an incentive for the development of other industries (hard coal mining, steelmaking). This, in consequence, resulted in progressive urbanization. The areas analyzed are of highly transformed character, mainly because of mining activities. These changes are especially seen in relation to the aquatic environment since this component is exposed to heavy modifications due to the mining processes. Hence the study was carried out in order to determine the quantitative changes in the surface hydrographic network. It was found, that of the 62 main watercourses (existing during the whole analyzed period) 25 changed only slightly in terms of their length, 20 shortened by a few hundred meters and 17 lengthened. In the case of the aggregated length of the tributaries, the value increased for the 41 main watercourses, for 10 of them it was constant and was reduced slightly for a further 11. The areas where the length of the watercourses increased and the drainage density grew were found to be as well those where the total area of wetlands decreased. The element of the hydrographic network which was affected by the most changes was the water bodies. During the analyzed period of over 200 years, their number increased from 154 to 1413.KEY WORDS: zinc and lead deposit, mining, Silesia-Cracow deposit area, hydrographic network, water body, wetland ARTICLE HISTORY: