Flow Duration Curves (FDC) for Selected Mountain Catchments in Slovakia.

The article presents the characteristics of the Flow Duration Frequency (FDC) curve statistics of the Hornád River and its tributaries for a period of 60 years (1961-2020) and compares the flow duration curves divided into decades (1961-1970, 1971-1980, 1981- 1990, 1991-2000, 2001-2010 and 2011-2020). High flows corresponding to the flow of 10% (Q10) and 25% (Q25), medium flows corresponding to the flow of 50% (Q50) and low flows corresponding to the flow of 70% (Q75) and 90% (Q90) were analyzed. The study covered 7 catchments located in the Hornád river catchment (eastern Slovakia). The greatest variability of flows in individual decades in relation to the multi-year period 1961-2020 was recorded in all threshold ranges at the station in Prešov Sekčov. The highest values were recorded in the range of low flows (Q90), for which the coefficient of variation was 0.38 (Q90) and 0.27 (Q75). A high coefficient of variation Cv was also recorded for the Košické Olšany station in terms of low flows for Q75 and Q90, which were 0.21 and 0.19, respectively. At the remaining stations, the variability of Cv ranged from 0.08 to 0.15 for Q75 and Q90. The variability of high flows (Q10 and Q25) ranged from 0.11 to 0.17 for all catchments except for the Prešov Sekčov station, for which the values were 0.21 and 0.27, and Stratená 0.19 and 0.18, respectively.