The role of the epikarst zone in karst aquifer recharge processes

The study of Orangeville Rise (USA, Indiana) and Hubelj (SW Slovenia) karst springs’storm hydrographs was the principal theme of our research. We used three and four component hydrograph separation techniques that were based on natural tracers. The resultsare similar in both study areas. They are in agreement with actual research hypothesis where it is supposed that an important part of the karst aquifer’s recharge arrives, rapidly and in concentrated form, from the epikrarst zone. The synthesis of data demonstrates thatepikarst water could occupy up to 50 % of the karst spring discharge during the precipitation event that should not be neglected in karst aquifer’s protection strategies.