The chemical composition of surface water and groundwater is subject to constant changes, which result primarily from meteorological factors (for instance, size and intensity of atmospheric precipitation), hydrological factors (for instance, the degree of hydration of the mountain massif and changes in river flows), and geological-lithological factors (the type of bedrock). The aim of the present research was to examine the hydrological and chemical regime of surface and underground waters in the Bystra and Sucha Woda mountain stream catchments.Between December 2013 and December 2016, 77 series of measurements were collected at the rhythm of twice a month (n = 611 water samples) from 8 sites, which represented both surface waters (watercourses, ponds) and underground waters (karst springs). The studied area possesses very distinct geological duality. The southern part is a crystalline region, and the northern part is made up of sedimentary rocks. During the field studies, the following have been measured: water levels of the watercourses, flow rates, and physicochemical characteristics of water, such as electrical conductivity, pH and water temperature. At the same time, water samples were collected for laboratory analyses, which included general mineralization and concentrations of Ca 2+ , Mg 2+ , Na + , K + , HCO 3 -Sajdak, M., Siwek, J., Bojarczuk, A., Żelazny, M. (2018). Hydrological and chemical water regime in the catchments of Bystra and Sucha Woda, in the Tatra National Park. Acta Sci. Pol., Formatio Circumiectus, 18(3), 161-173. DOI: 162 www.formatiocircumiectus.actapol.net/pl/ composition of the Bystra stream water, draining the crystalline-sedimentary (karst) part of the catchment, was strictly dependent on the chemical composition of groundwater from the Goryczkowy and lower Bystra karst springs.
