Hydrology and hydrogeology of Bubovice Stream

The Bubovice stream is typical by sinking water in some segments. Especially in last years the loss of water is so high, that the stream riverbed is mostly completely dry except the topmost part of the stream. What determines the intense water losses in Bubovice stream is considered an important issue. The objective of this theses was to determine the causes of water losses and find out, if at least a minimum flow of Bubovice stream could be restored. The solution of the problem is very complex, because the Bubovice stream basin is located in a karst region of Bohemian Karst, which is typical by its complex water flow in heterogenous rock environment. Historical documents show that water losses occurred already 80 years ago, before recent climatic change. The water losses are at present time twice as high as were in 1990s in the upper part of catchment of Bubovice stream based on discharge measurements. The losses are caused mainly by infiltration of water to limestone. The contribution of evapotranspiration to water losses is marginal. It was found that 2 out of 5 parts of stream catchment show permanent water losses. Based on very different concentrations of sodium and chloride ions it is evident, that water that sinks in the upper part of Bubovice stream catchment flows away from the orographic..