Karst can be found all over the Slovenia with the exception of its northeastern part. Karst aquifers are an important source of drinking water, but due to their characteristics can also be very vulnerable. The Master thesis includes an analysis of annual low, mean and maximum daily discharge or water level trends for 14 karst springs in Slovenia. Time series of 53 years was used in the analysis, with the exception of three karst springs with shorter sets of hydrological data measurements. The process of karst formation, characteristics of karst aquifer and the mechanism of water flow and recharging in the karst aquifer are presented. Additionally, different types of karst springs are described and a general overview of karst springs in Slovenia is given. Statistical analysis of the discharge trends was performed by using the Mann-Kendall test and method of linear regression. Trend change point in mean annual discharge was detected by using the Pettitt test. Detected change point divided the mean annual discharge time series in two separate time series and trend for subseries was analysed.
All time series used in the thesis were previously reviewed and missing values were filled in, so only complete times series of hydrological and meteorological data were used. Trends and changes in water temperature were analysed for 7 karst springs.
Trends in annual amount of precipitation and trends in air temperature for selected meteorological stations were also identified. Correlation between annual amounts of precipitation and discharges were calculated as well.
The results of hydrological analysis show statistically significant decrease in mean annual discharge in 12 of the 14 karst springs that were included in the analysis. Additionally a decreasing trend in annual low discharge values for 11 out of 14 karst springs was detected. Water temperature is increasing in 5 of 7 selected karst springs - for 3 of them the increasing trend is also statistically significant. Year 1982 was most often detected as the change point in the investigated samples.