Evaluation of Ecological Flow and Concentrations of Pollutants in Selected River Basin in Eastern Slovakia

From the hydrological characteristics of the stream and river basins are particularly serious its extremes, that is, maximum and minimum flow rates and water levels. In the past, emphasis was placed on maximum discharges that occur in river basins and that are usually catastrophic. Currently, the emphasis is also put on the minimum flow rate - coupled with drought. Processing of the minimum (ecological) monthly discharges and their evaluation and trend lines is also the subject of this paper. Scientific aspect of the work is determination of minimum flow and also the evaluation of water quality through the concentration of pollutants in the water flow. Data were obtained from the Slovak Hydrometeorological Institute and include minimum monthly flow rates (for the period from 1995 to 2013) from river stations in Eastern Slovakia: Svit (river Poprad), Ižkovce (river Laborec), KoÅ¡ické OlÅ¡any (river Torysa) and concentrations of pollutants (Ptot, N-NO2) from the same hydrometric stations for the same years. Concentrations of pollutants have decreasing trend (for almost all cases) in the monitored period.